Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
On 6/25/11 5:03 PM, Neville Michie wrote: An interesting question about making a 50/60 hertz source, Does a 120 to 12 volt transformer have enough inductance to use as a 12 to 120 volt transformer? Remember, the inductance is proportional to the square of the no of turns, where as voltage is proportional. sure... you're thinking about the turns per volt/core cross section kind of thing, right? If it works for 120/12, it will work for 12/120. Where you would get into trouble is trying to use it for 24/240 or something. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Group, My plan for precision 60 Hz was to use a Caesium standard and an HP 3320B synthesizer. At about that time, some 200 watt amplifiers became available on eBay. They were designed for public buildings to do elevator music or emergency announcements. Accordingly, they ran on 120 VAC 60 Hz or 28 VDC. 24 VDC was fine but wouldn't quite deliver 200 watts. I bought two. The transformers are large, and have 70.7 volt line outputs. Low voltage boost transformers can get closer to 120 VAC if turning up the volume won't do it. Never got around to it, and need to lighten the load on the basement floor. The Caesium standard has been sold. Please write to b...@iaxs.net for details. I'm in Minneapolis, MN. Also have a Liebert 2 KW sine wave UPS that requires 96 VDC. Bought eight 12V 33 AH batteries for it to keep the time rack running. Six of them died with shorted cells after 6 years, so the Liebert is available. Bill Hawkins ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Last year I picked up a frequency standard that inputs 120VAC (or 12V DC) and drives a 6 0Hz Synchron motor based clock and also has a 120V 60 CPS output on the back. I wasn't sure what I was going to do with it, but now I know I can run my old telechron synchronous clocks with this when the power companies stop the 60Hz. There is no manufacturer's name on the unit, but maybe a list member can identify it from the pictures at: http://www.telechron.com/60CPS/60CPS.html ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Mitchell, I'm not sure, as I couldn't see anything to hint at the maker on the cabinet. I also couldn't see who made the clock movement either, as their was no name on the clock face. Of course, companies like HP and others bought those from a good OEM manufacturer to use, so I doubt they made the movement. I take it that that is an ocxo on the one side? If so, there could be some identifying mark on the case somewhere, or inside the metal box. Another place to look would be on either side of the PC board, especially on the trace side, as they sometimes etched the company name on them. I wouldn't mind owning one of these myself, it's neat! Best, Will *** REPLY SEPARATOR *** On 6/26/2011 at 6:06 PM Mitchell Janoff wrote: Last year I picked up a frequency standard that inputs 120VAC (or 12V DC) and drives a 6 0Hz Synchron motor based clock and also has a 120V 60 CPS output on the back. I wasn't sure what I was going to do with it, but now I know I can run my old telechron synchronous clocks with this when the power companies stop the 60Hz. There is no manufacturer's name on the unit, but maybe a list member can identify it from the pictures at: http://www.telechron.com/60CPS/60CPS.html ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Hello Mitchell, I believe this is a W. F. Sprengnether Instrument Co. Inc. TS-100 (presumably used for driving seismometers). I have a pretty much identical unit and it remained a mystery until I took the rack panel off to reveal the logo on the front of the chassis. http://www.bdairfield.com/stan/time-nuts/Sprengnether-clock/IMG_4547.JPG I think that when I got my unit, the cover was flipped around so the top overhang was on the back. This way the overhang does not run into the rack panel, but it puts the frequency adjust hole on the wrong side of the unit. In the picture above, you can see the (presumably) OCXO with its cover removed. There is a heater around the outside of the crystal housing. What I presume is the dividers have a silicon compound dribbled over them. In this area is 10 red modules (at least one of which is 7 pins and marked Erie 22254A). The circuitry that presumably drives the transformer for the 60 Hz output includes a 2N1302, a 2N1303 and three power transistors that I think are marked 2N456A. I don't think I'd put mine in my bedroom. It clicks pretty loudly every minute. Stan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Mitchell Janoff Sent: Sunday, June 26, 2011 3:06 PM To: time-nuts@febo.com Subject: Re: [time-nuts] No more 60Hz,How do I discipline 120VAC 60Hz from a UPS Last year I picked up a frequency standard that inputs 120VAC (or 12V DC) and drives a 6 0Hz Synchron motor based clock and also has a 120V 60 CPS output on the back. I wasn't sure what I was going to do with it, but now I know I can run my old telechron synchronous clocks with this when the power companies stop the 60Hz. There is no manufacturer's name on the unit, but maybe a list member can identify it from the pictures at: http://www.telechron.com/60CPS/60CPS.html ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
I collect clocks an have many clocks with 60Hz Synchronous Motors. How would I go about Disciplining a 60Hz 120VAC source from an Unintteruptable Power Supply (UPS)? This would solve both my problem with power outages and the new problem of possibly undisciplined power from the power companies (Henry Warren must be rolling over in his grave!) I have no Idea how you would disciple such a low frequency at such a high voltage and deliver the power required to drive several (or many) Clocks. I assume you would start with a commercially available UPS and either a disciplined 1 Second or 10Mhz source such as a thunderbolt (also powered off the UPS or the batteries in the UPS). Does anyone have an suggestions for circuits which would do this disciplining? Thanks Don ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Don, The easiest way would be to convert the line voltage to make a 12 Vdc source, then use an inverter that you can add a xtal control to its oscillator, or even add a GPS disciplined source to drive it. However, that won't help with power outage, unless you would use a UPS, or maybe a generator that will kick in when the line voltage starts to drop. The transformer to use is a simple 24 Vac, center tap secondary, that you then use as the primary, and drive it with 12 volts on either side with the oscillator. You feed the center tap with 12 Vdc, and switch the two outer legs to ground via transistors or FET's. The secondary is what was the 120 Vac primary, and you have to source for the clocks. I built a 60 Hz inverter a few years back, and it didn't really require much. I can't recall the chip I used for the oscillator, but it did work, and it gave me 60 Hz like I wanted. Most cheaper inverters, if I remember, run at a higher frequency than that, which are now sold on the market. They do this to get the transformer size down. While you're at it, you might want to check the motors loaded rpm in those clocks to see how accurate they are. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 9:50 AM Don Mimlitch wrote: I collect clocks an have many clocks with 60Hz Synchronous Motors. How would I go about Disciplining a 60Hz 120VAC source from an Unintteruptable Power Supply (UPS)? This would solve both my problem with power outages and the new problem of possibly undisciplined power from the power companies (Henry Warren must be rolling over in his grave!) I have no Idea how you would disciple such a low frequency at such a high voltage and deliver the power required to drive several (or many) Clocks. I assume you would start with a commercially available UPS and either a disciplined 1 Second or 10Mhz source such as a thunderbolt (also powered off the UPS or the batteries in the UPS). Does anyone have an suggestions for circuits which would do this disciplining? Thanks Don ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
I would suggest looking at double conversion UPSs. The plain UPSs put out square waves (more or less). A double conversion UPS takes the mains, converts to DC, filters it big time (easier to do with DC), the creates a true sine wave. These show up on craigslist often. -Original Message- From: Don Mimlitch donm...@yahoo.com Sender: time-nuts-boun...@febo.com Date: Sat, 25 Jun 2011 09:50:01 To: time-nuts@febo.comtime-nuts@febo.com Reply-To: Don Mimlitch donm...@yahoo.com, Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS I collect clocks an have many clocks with 60Hz Synchronous Motors. How would I go about Disciplining a 60Hz 120VAC source from an Unintteruptable Power Supply (UPS)? This would solve both my problem with power outages and the new problem of possibly undisciplined power from the power companies (Henry Warren must be rolling over in his grave!) I have no Idea how you would disciple such a low frequency at such a high voltage and deliver the power required to drive several (or many) Clocks. I assume you would start with a commercially available UPS and either a disciplined 1 Second or 10Mhz source such as a thunderbolt (also powered off the UPS or the batteries in the UPS). Does anyone have an suggestions for circuits which would do this disciplining? Thanks Don ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
On Sat, Jun 25, 2011 at 9:50 AM, Don Mimlitch donm...@yahoo.com wrote: I collect clocks an have many clocks with 60Hz Synchronous Motors. How would I go about Disciplining a 60Hz 120VAC source from an Unintteruptable Power Supply (UPS)? Most comercial UPS are quite crude. Theu make square wave AC. In your case, I think the way to go is to build a precision 60 Hz oscillator . It can be very low power and work at 5 volts. I would deriv the 60Hz from a 10Mhz reference, either devide it down then drive a PLL or use a DDS chip.Filer it then usethis precission 60Hz signal to feed something that looks a lot like an audio amplifier. This kind of design is expensive if you need many watts but you clocks likely don't need many watts. The amplified can run from a high voltage DC source. As (I assume) we don't care about efficiency you can drive the amp with a 200V DC linear supply like you'd find in a tube based amp. the feedback loop of the typical audio amp is replaced be an an AC voltage comparator. Feed back drive the output to exactly 120V. Use a different design if you care about power consumption and waste heat. The above is a simple on line supply. A comerical UPS like this is more complex and uses a SMPS for the high voltage and runs the SMPS from a battery that is also being charged from AC mains. These use a crystal for a freq. reference. You might just buy one and replace the crystal with a DDS drive from your 10Mhz reference. But these comercial on-line units are not cheap like home computer backups -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
There is a story about BF Skinner, the behavioral professor. His students decided to change his behavior. They took the synchronous clock on the wall and hooked it up to a variable frequency power source. Every class, they would increase the frequency a bit. Skinner would teach faster and faster until he caught on to the trick. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Chris, That's close to what I did, but I think the chips output to the switching transistors was a modified squarewave, made to act like a sine wave, where the waveform is stair-stepped. One could use a plain 60Hz crystal controlled oscillator, and start out with push-pull amplifier stages to get to the final switching power you need, the same or similar as building up a push-pull transmitter. The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap, with quite high power ratings. Any switching types like this do require extra power which is expended in heat, and you would have to calculate those losses for the main DC supply transformer. Motorola had an application note on doing this in their catalogs around 1965-1970. That was back in the time of the large Ger. switching transistors too. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 10:25 AM Chris Albertson wrote: On Sat, Jun 25, 2011 at 9:50 AM, Don Mimlitch donm...@yahoo.com wrote: I collect clocks an have many clocks with 60Hz Synchronous Motors. How would I go about Disciplining a 60Hz 120VAC source from an Unintteruptable Power Supply (UPS)? Most comercial UPS are quite crude. Theu make square wave AC. In your case, I think the way to go is to build a precision 60 Hz oscillator . It can be very low power and work at 5 volts. I would deriv the 60Hz from a 10Mhz reference, either devide it down then drive a PLL or use a DDS chip.Filer it then usethis precission 60Hz signal to feed something that looks a lot like an audio amplifier. This kind of design is expensive if you need many watts but you clocks likely don't need many watts. The amplified can run from a high voltage DC source. As (I assume) we don't care about efficiency you can drive the amp with a 200V DC linear supply like you'd find in a tube based amp. the feedback loop of the typical audio amp is replaced be an an AC voltage comparator. Feed back drive the output to exactly 120V. Use a different design if you care about power consumption and waste heat. The above is a simple on line supply. A comerical UPS like this is more complex and uses a SMPS for the high voltage and runs the SMPS from a battery that is also being charged from AC mains. These use a crystal for a freq. reference. You might just buy one and replace the crystal with a DDS drive from your 10Mhz reference. But these comercial on-line units are not cheap like home computer backups -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Depending on your skills and amount of time you want to spend on this: 1. As you said, find a commercial UPS and just tie it to a time-nuts grade 10MHz. I assume most modern UPS will be based on a $1 ARM or PIC processor - if they run on external oscillator you can use a DDS chip to generate the exact frequency they need to generate your 60. Hz. You would need to find out the exact fractional relationship they use for this. For instance, say a micro runs from a 25MHz oscillator, has an internal 10kHz interrupt that flips the output square wave every 83 counts. It generates a 60.24Hz that was 'OK' for the original product. You would want to feed it with 24.9MHz, derived from your good 10MHz via DDS. The risk is that some UPS might just use micro's internal oscillator with no access. 2. If you want to go a little further (and possibly spend more money in parts than a commercial UPS would cost you), you can use that DDS to output 60Hz and drive the monster FETs directly (well some isolation / gate driver required). Simplest is square wave, switch between sink/source to +/- DC rails. Linear drive (like class B amp) to generate is inefficient. Filtering square wave leads to large passives. Filtering stepped square waves is a bit better, but switching between two rails with high frequency PWM will generate a sine wave that is simpler to filter. Possibly you can find some kit or schematics on the web, just replace the time base... I'd get a good sinewave UPS (compare eBay, old, assume bad battery, compare to new, Hong Kong) and add a REF-IN BNC to a DDS. -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Don Mimlitch Sent: Saturday, June 25, 2011 9:50 AM To: time-nuts@febo.com Subject: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS I collect clocks an have many clocks with 60Hz Synchronous Motors. How would I go about Disciplining a 60Hz 120VAC source from an Unintteruptable Power Supply (UPS)? This would solve both my problem with power outages and the new problem of possibly undisciplined power from the power companies (Henry Warren must be rolling over in his grave!) I have no Idea how you would disciple such a low frequency at such a high voltage and deliver the power required to drive several (or many) Clocks. I assume you would start with a commercially available UPS and either a disciplined 1 Second or 10Mhz source such as a thunderbolt (also powered off the UPS or the batteries in the UPS). Does anyone have an suggestions for circuits which would do this disciplining? Thanks Don ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
The cheapie inverters I've seen use a hgh frequency DC-DC cnverter to make about 170 VDC, and then an H-bridge output stage, driven with a modified square wave to make the AC. Pretty crummy, IMO. -John == Don, The easiest way would be to convert the line voltage to make a 12 Vdc source, then use an inverter that you can add a xtal control to its oscillator, or even add a GPS disciplined source to drive it. However, that won't help with power outage, unless you would use a UPS, or maybe a generator that will kick in when the line voltage starts to drop. The transformer to use is a simple 24 Vac, center tap secondary, that you then use as the primary, and drive it with 12 volts on either side with the oscillator. You feed the center tap with 12 Vdc, and switch the two outer legs to ground via transistors or FET's. The secondary is what was the 120 Vac primary, and you have to source for the clocks. I built a 60 Hz inverter a few years back, and it didn't really require much. I can't recall the chip I used for the oscillator, but it did work, and it gave me 60 Hz like I wanted. Most cheaper inverters, if I remember, run at a higher frequency than that, which are now sold on the market. They do this to get the transformer size down. While you're at it, you might want to check the motors loaded rpm in those clocks to see how accurate they are. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 9:50 AM Don Mimlitch wrote: I collect clocks an have many clocks with 60Hz Synchronous Motors. How would I go about Disciplining a 60Hz 120VAC source from an Unintteruptable Power Supply (UPS)? This would solve both my problem with power outages and the new problem of possibly undisciplined power from the power companies (Henry Warren must be rolling over in his grave!) I have no Idea how you would disciple such a low frequency at such a high voltage and deliver the power required to drive several (or many) Clocks. I assume you would start with a commercially available UPS and either a disciplined 1 Second or 10Mhz source such as a thunderbolt (also powered off the UPS or the batteries in the UPS). Does anyone have an suggestions for circuits which would do this disciplining? Thanks Don ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
If I were tasked with this job, I'd buy an older UPS of adequate size for your load, with the ability to use external batteries, that puts out either sine or modified square waves. Older, because the controller will be easier to modify. BUT, before purchase, I'd make sure that, at least, a schematic is available. IMO, the easiest route is a modified UPS. The biggest task will be getting the prints. FWIW, -John == Don, The easiest way would be to convert the line voltage to make a 12 Vdc source, then use an inverter that you can add a xtal control to its oscillator, or even add a GPS disciplined source to drive it. However, that won't help with power outage, unless you would use a UPS, or maybe a generator that will kick in when the line voltage starts to drop. The transformer to use is a simple 24 Vac, center tap secondary, that you then use as the primary, and drive it with 12 volts on either side with the oscillator. You feed the center tap with 12 Vdc, and switch the two outer legs to ground via transistors or FET's. The secondary is what was the 120 Vac primary, and you have to source for the clocks. I built a 60 Hz inverter a few years back, and it didn't really require much. I can't recall the chip I used for the oscillator, but it did work, and it gave me 60 Hz like I wanted. Most cheaper inverters, if I remember, run at a higher frequency than that, which are now sold on the market. They do this to get the transformer size down. While you're at it, you might want to check the motors loaded rpm in those clocks to see how accurate they are. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 9:50 AM Don Mimlitch wrote: I collect clocks an have many clocks with 60Hz Synchronous Motors. How would I go about Disciplining a 60Hz 120VAC source from an Unintteruptable Power Supply (UPS)? This would solve both my problem with power outages and the new problem of possibly undisciplined power from the power companies (Henry Warren must be rolling over in his grave!) I have no Idea how you would disciple such a low frequency at such a high voltage and deliver the power required to drive several (or many) Clocks. I assume you would start with a commercially available UPS and either a disciplined 1 Second or 10Mhz source such as a thunderbolt (also powered off the UPS or the batteries in the UPS). Does anyone have an suggestions for circuits which would do this disciplining? Thanks Don ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
I remember that on the NASA Manned Flight Tracking Stations during the Apollo program, inside one of the racks of the timing subsystem was a big Marantz HiFi amplifier. It was used to amplify a 60 Hz signal derived from the Cesium reference to drive the common wall clocks that were in many places. Of course, the operations time displays were digital. Regards, Ignacio, EB4APL On 25/06/2011 18:50, Don Mimlitch wrote: I collect clocks an have many clocks with 60Hz Synchronous Motors. How would I go about Disciplining a 60Hz 120VAC source from an Unintteruptable Power Supply (UPS)? This would solve both my problem with power outages and the new problem of possibly undisciplined power from the power companies (Henry Warren must be rolling over in his grave!) I have no Idea how you would disciple such a low frequency at such a high voltage and deliver the power required to drive several (or many) Clocks. I assume you would start with a commercially available UPS and either a disciplined 1 Second or 10Mhz source such as a thunderbolt (also powered off the UPS or the batteries in the UPS). Does anyone have an suggestions for circuits which would do this disciplining? Thanks Don ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap That's a good point.So use two of them. One to power a high current amp that produces a 12V AC signal from a high precision 60Hz input. Then the other to convert the 12V to 120V. This avoids the need for a high voltage DC power supply. Likely cuts the total cost in half at least. So just use use 12V supply to the amp and then a cheap 12V transformer connected backwards to step up to the desired voltage. The second advantage of this design is that you can connect a lead acid gell cell battery in parallel to the 12V DC supply and if the AC fails the battery will power the amp for a while. This way there is no switching so the 60Hz wave remains continuously even if AC mains fails. This is something most UPS don't do but for this application you don't want the 60Hz sine wave to be broken. As long as the load is only a few milliamps of AC this should not be hard to do. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
More clock memories... I remember in school the wall clocks would synchronize. I assume their was a company that made what we would call a networked clock today. This synchronization would occasionally make the clock go backwards. HP at one time had a Cesium reference/clock in the lobby of their Santa Clara site. Supposedly it was also the 10MHz reference for the facility. This is the place where Apple is going to build the spaceship. Sacrilege in my opinion. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Chris, Yup, that's all I did. Use the line to keep the batteries charging, and when the line goes down, the battery or batteries just keep on supplying the system. Mine wasn't a sine wave though, but a modified square wave, however it worked like a charm. I got the idea from a website, and modified it to my taste, but it really didn't cost much with all the surplus transformers available, and there is a huge number available with high power ratings. I used a bank of NPN switching transistors, and I forget what they were, but they had slightly higher ratings than a 2N3055. There was a driver circuit between them and the chip. I can't remember if Maxim, or another, made the IC, as I would have to try to find my info on the supply, because I sold it about two years after I finished it. One could try to find an older sine wave UPS, and modify it, but it would need to be a 60Hz output supply, because the transformer would be sized incorrectly, with a higher frequency rating, when dropping it down to 60 Hz. As John mentioned earlier, the el-cheapo inverters are pretty much junk, and run as high as 1 kHz, if I recall. They were made to run small TV's, etc, that don't require a fixed line frequency, since they all have hot chassis now that don't use isolation transformers. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 11:55 AM Chris Albertson wrote: The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap That's a good point.So use two of them. One to power a high current amp that produces a 12V AC signal from a high precision 60Hz input. Then the other to convert the 12V to 120V. This avoids the need for a high voltage DC power supply. Likely cuts the total cost in half at least. So just use use 12V supply to the amp and then a cheap 12V transformer connected backwards to step up to the desired voltage. The second advantage of this design is that you can connect a lead acid gell cell battery in parallel to the 12V DC supply and if the AC fails the battery will power the amp for a while. This way there is no switching so the 60Hz wave remains continuously even if AC mains fails. This is something most UPS don't do but for this application you don't want the 60Hz sine wave to be broken. As long as the load is only a few milliamps of AC this should not be hard to do. -- Chris Albertson Redondo Beach, California __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Chris, No I didn't say the output was 1000 Hz. No way. What I said (a bit amplified) was that the cheapie inverters use a high frequency, think 50 KHzish, DC-DC converter to make about 170 VDC, then use that to feed an H bridge, driven with either a square wave or a modified square wave, to make the output. You snmply need to vary that drive frequency to get 50, or 60, or any frequency you want. There is no output transformer. In fact, that is the cleverness of the design... no big, heavy, expensive magnetics. -John === As John mentioned earlier, the el-cheapo inverters are pretty much junk, and run as high as 1 kHz, if I recall. They were made to run small TV's, etc, that don't require a fixed line frequency, since they all have hot chassis now that don't use isolation transformers. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 11:55 AM Chris Albertson wrote: The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap That's a good point.So use two of them. One to power a high current amp that produces a 12V AC signal from a high precision 60Hz input. Then the other to convert the 12V to 120V. This avoids the need for a high voltage DC power supply. Likely cuts the total cost in half at least. So just use use 12V supply to the amp and then a cheap 12V transformer connected backwards to step up to the desired voltage. The second advantage of this design is that you can connect a lead acid gell cell battery in parallel to the 12V DC supply and if the AC fails the battery will power the amp for a while. This way there is no switching so the 60Hz wave remains continuously even if AC mains fails. This is something most UPS don't do but for this application you don't want the 60Hz sine wave to be broken. As long as the load is only a few milliamps of AC this should not be hard to do. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
John, I didn't mean to say you said all that, just that the new inverters are cheap. I wrote that I thought some ran at around 1 kHZ, as I had an old one that did, and used a toroidal transformer in it. The new ones, as far as I am aware, are similar to the new-style switching power supplies, like the ones Maxim and a few others show in their app notes. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:37 PM J. Forster wrote: Chris, No I didn't say the output was 1000 Hz. No way. What I said (a bit amplified) was that the cheapie inverters use a high frequency, think 50 KHzish, DC-DC converter to make about 170 VDC, then use that to feed an H bridge, driven with either a square wave or a modified square wave, to make the output. You snmply need to vary that drive frequency to get 50, or 60, or any frequency you want. There is no output transformer. In fact, that is the cleverness of the design... no big, heavy, expensive magnetics. -John === As John mentioned earlier, the el-cheapo inverters are pretty much junk, and run as high as 1 kHz, if I recall. They were made to run small TV's, etc, that don't require a fixed line frequency, since they all have hot chassis now that don't use isolation transformers. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 11:55 AM Chris Albertson wrote: The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap That's a good point.So use two of them. One to power a high current amp that produces a 12V AC signal from a high precision 60Hz input. Then the other to convert the 12V to 120V. This avoids the need for a high voltage DC power supply. Likely cuts the total cost in half at least. So just use use 12V supply to the amp and then a cheap 12V transformer connected backwards to step up to the desired voltage. The second advantage of this design is that you can connect a lead acid gell cell battery in parallel to the 12V DC supply and if the AC fails the battery will power the amp for a while. This way there is no switching so the 60Hz wave remains continuously even if AC mains fails. This is something most UPS don't do but for this application you don't want the 60Hz sine wave to be broken. As long as the load is only a few milliamps of AC this should not be hard to do. -- Chris Albertson Redondo Beach, California __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Certainly, the inverters can run that low, but if so they sing a lot. Best, -John = John, I didn't mean to say you said all that, just that the new inverters are cheap. I wrote that I thought some ran at around 1 kHZ, as I had an old one that did, and used a toroidal transformer in it. The new ones, as far as I am aware, are similar to the new-style switching power supplies, like the ones Maxim and a few others show in their app notes. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:37 PM J. Forster wrote: Chris, No I didn't say the output was 1000 Hz. No way. What I said (a bit amplified) was that the cheapie inverters use a high frequency, think 50 KHzish, DC-DC converter to make about 170 VDC, then use that to feed an H bridge, driven with either a square wave or a modified square wave, to make the output. You snmply need to vary that drive frequency to get 50, or 60, or any frequency you want. There is no output transformer. In fact, that is the cleverness of the design... no big, heavy, expensive magnetics. -John === As John mentioned earlier, the el-cheapo inverters are pretty much junk, and run as high as 1 kHz, if I recall. They were made to run small TV's, etc, that don't require a fixed line frequency, since they all have hot chassis now that don't use isolation transformers. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 11:55 AM Chris Albertson wrote: The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap That's a good point.So use two of them. One to power a high current amp that produces a 12V AC signal from a high precision 60Hz input. Then the other to convert the 12V to 120V. This avoids the need for a high voltage DC power supply. Likely cuts the total cost in half at least. So just use use 12V supply to the amp and then a cheap 12V transformer connected backwards to step up to the desired voltage. The second advantage of this design is that you can connect a lead acid gell cell battery in parallel to the 12V DC supply and if the AC fails the battery will power the amp for a while. This way there is no switching so the 60Hz wave remains continuously even if AC mains fails. This is something most UPS don't do but for this application you don't want the 60Hz sine wave to be broken. As long as the load is only a few milliamps of AC this should not be hard to do. -- Chris Albertson Redondo Beach, California __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
John, Yes, this one whined when it ran. It was under the seat in a pop-up camper I owned. It had a battery hold down in the floor, and the inverter was bolted to the wall behind it. The only way to muffle the whine was to have the seat cushion in place. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:55 PM J. Forster wrote: Certainly, the inverters can run that low, but if so they sing a lot. Best, -John = John, I didn't mean to say you said all that, just that the new inverters are cheap. I wrote that I thought some ran at around 1 kHZ, as I had an old one that did, and used a toroidal transformer in it. The new ones, as far as I am aware, are similar to the new-style switching power supplies, like the ones Maxim and a few others show in their app notes. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:37 PM J. Forster wrote: Chris, No I didn't say the output was 1000 Hz. No way. What I said (a bit amplified) was that the cheapie inverters use a high frequency, think 50 KHzish, DC-DC converter to make about 170 VDC, then use that to feed an H bridge, driven with either a square wave or a modified square wave, to make the output. You snmply need to vary that drive frequency to get 50, or 60, or any frequency you want. There is no output transformer. In fact, that is the cleverness of the design... no big, heavy, expensive magnetics. -John === As John mentioned earlier, the el-cheapo inverters are pretty much junk, and run as high as 1 kHz, if I recall. They were made to run small TV's, etc, that don't require a fixed line frequency, since they all have hot chassis now that don't use isolation transformers. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 11:55 AM Chris Albertson wrote: The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap That's a good point.So use two of them. One to power a high current amp that produces a 12V AC signal from a high precision 60Hz input. Then the other to convert the 12V to 120V. This avoids the need for a high voltage DC power supply. Likely cuts the total cost in half at least. So just use use 12V supply to the amp and then a cheap 12V transformer connected backwards to step up to the desired voltage. The second advantage of this design is that you can connect a lead acid gell cell battery in parallel to the 12V DC supply and if the AC fails the battery will power the amp for a while. This way there is no switching so the 60Hz wave remains continuously even if AC mains fails. This is something most UPS don't do but for this application you don't want the 60Hz sine wave to be broken. As long as the load is only a few milliamps of AC this should not be hard to do. -- Chris Albertson Redondo Beach, California __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
John, I forgot to add, that an H bridge could work for a clock motor, since those are used to drive ac motors in industry every day. You would have a sqauare wave though, unless it was modified. If I recall, that's the way a lot of the AC drives work today, using four sets of switching semiconductors, unless the motor is small enough to be ran off a power chip. In this case, I wonder how an AC drive would act if it ran a clock motor? Set it at 60 Hz, and be done with it? Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:55 PM J. Forster wrote: Certainly, the inverters can run that low, but if so they sing a lot. Best, -John = John, I didn't mean to say you said all that, just that the new inverters are cheap. I wrote that I thought some ran at around 1 kHZ, as I had an old one that did, and used a toroidal transformer in it. The new ones, as far as I am aware, are similar to the new-style switching power supplies, like the ones Maxim and a few others show in their app notes. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:37 PM J. Forster wrote: Chris, No I didn't say the output was 1000 Hz. No way. What I said (a bit amplified) was that the cheapie inverters use a high frequency, think 50 KHzish, DC-DC converter to make about 170 VDC, then use that to feed an H bridge, driven with either a square wave or a modified square wave, to make the output. You snmply need to vary that drive frequency to get 50, or 60, or any frequency you want. There is no output transformer. In fact, that is the cleverness of the design... no big, heavy, expensive magnetics. -John === As John mentioned earlier, the el-cheapo inverters are pretty much junk, and run as high as 1 kHz, if I recall. They were made to run small TV's, etc, that don't require a fixed line frequency, since they all have hot chassis now that don't use isolation transformers. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 11:55 AM Chris Albertson wrote: The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap That's a good point.So use two of them. One to power a high current amp that produces a 12V AC signal from a high precision 60Hz input. Then the other to convert the 12V to 120V. This avoids the need for a high voltage DC power supply. Likely cuts the total cost in half at least. So just use use 12V supply to the amp and then a cheap 12V transformer connected backwards to step up to the desired voltage. The second advantage of this design is that you can connect a lead acid gell cell battery in parallel to the 12V DC supply and if the AC fails the battery will power the amp for a while. This way there is no switching so the 60Hz wave remains continuously even if AC mains fails. This is something most UPS don't do but for this application you don't want the 60Hz sine wave to be broken. As long as the load is only a few milliamps of AC this should not be hard to do. -- Chris Albertson Redondo Beach, California __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Sorry, that should have said DC drive, as I was writing while brain storming. However, a variable AC drive, which does control the frequency, may be able to be used. I would have to look at this more, but it might be possible, and these can be bought on the cheap at surplus sellers. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 4:12 PM Will Matney wrote: John, I forgot to add, that an H bridge could work for a clock motor, since those are used to drive ac motors in industry every day. You would have a sqauare wave though, unless it was modified. If I recall, that's the way a lot of the AC drives work today, using four sets of switching semiconductors, unless the motor is small enough to be ran off a power chip. In this case, I wonder how an AC drive would act if it ran a clock motor? Set it at 60 Hz, and be done with it? Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:55 PM J. Forster wrote: Certainly, the inverters can run that low, but if so they sing a lot. Best, -John = John, I didn't mean to say you said all that, just that the new inverters are cheap. I wrote that I thought some ran at around 1 kHZ, as I had an old one that did, and used a toroidal transformer in it. The new ones, as far as I am aware, are similar to the new-style switching power supplies, like the ones Maxim and a few others show in their app notes. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:37 PM J. Forster wrote: Chris, No I didn't say the output was 1000 Hz. No way. What I said (a bit amplified) was that the cheapie inverters use a high frequency, think 50 KHzish, DC-DC converter to make about 170 VDC, then use that to feed an H bridge, driven with either a square wave or a modified square wave, to make the output. You snmply need to vary that drive frequency to get 50, or 60, or any frequency you want. There is no output transformer. In fact, that is the cleverness of the design... no big, heavy, expensive magnetics. -John === As John mentioned earlier, the el-cheapo inverters are pretty much junk, and run as high as 1 kHz, if I recall. They were made to run small TV's, etc, that don't require a fixed line frequency, since they all have hot chassis now that don't use isolation transformers. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 11:55 AM Chris Albertson wrote: The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap That's a good point.So use two of them. One to power a high current amp that produces a 12V AC signal from a high precision 60Hz input. Then the other to convert the 12V to 120V. This avoids the need for a high voltage DC power supply. Likely cuts the total cost in half at least. So just use use 12V supply to the amp and then a cheap 12V transformer connected backwards to step up to the desired voltage. The second advantage of this design is that you can connect a lead acid gell cell battery in parallel to the 12V DC supply and if the AC fails the battery will power the amp for a while. This way there is no switching so the 60Hz wave remains continuously even if AC mains fails. This is something most UPS don't do but for this application you don't want the 60Hz sine wave to be broken. As long as the load is only a few milliamps of AC this should not be hard to do. -- Chris Albertson Redondo Beach, California __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
John, I forgot to add, that an H bridge could work for a clock motor, since those are used to drive ac motors in industry every day. Yes, of course. You would have a sqauare wave though, unless it was modified. If I recall, that's the way a lot of the AC drives work today, using four sets of switching semiconductors, unless the motor is small enough to be ran off a power chip. In this case, I wonder how an AC drive would act if it ran a clock motor? The static inverters should not have issues with an induction motor. Set it at 60 Hz, and be done with it? Yes, but you have to get to the H bridge timing logic to do that. That's why you need the prints. -John === Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:55 PM J. Forster wrote: Certainly, the inverters can run that low, but if so they sing a lot. Best, -John = John, I didn't mean to say you said all that, just that the new inverters are cheap. I wrote that I thought some ran at around 1 kHZ, as I had an old one that did, and used a toroidal transformer in it. The new ones, as far as I am aware, are similar to the new-style switching power supplies, like the ones Maxim and a few others show in their app notes. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:37 PM J. Forster wrote: Chris, No I didn't say the output was 1000 Hz. No way. What I said (a bit amplified) was that the cheapie inverters use a high frequency, think 50 KHzish, DC-DC converter to make about 170 VDC, then use that to feed an H bridge, driven with either a square wave or a modified square wave, to make the output. You snmply need to vary that drive frequency to get 50, or 60, or any frequency you want. There is no output transformer. In fact, that is the cleverness of the design... no big, heavy, expensive magnetics. -John === As John mentioned earlier, the el-cheapo inverters are pretty much junk, and run as high as 1 kHz, if I recall. They were made to run small TV's, etc, that don't require a fixed line frequency, since they all have hot chassis now that don't use isolation transformers. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 11:55 AM Chris Albertson wrote: The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap That's a good point.So use two of them. One to power a high current amp that produces a 12V AC signal from a high precision 60Hz input. Then the other to convert the 12V to 120V. This avoids the need for a high voltage DC power supply. Likely cuts the total cost in half at least. So just use use 12V supply to the amp and then a cheap 12V transformer connected backwards to step up to the desired voltage. The second advantage of this design is that you can connect a lead acid gell cell battery in parallel to the 12V DC supply and if the AC fails the battery will power the amp for a while. This way there is no switching so the 60Hz wave remains continuously even if AC mains fails. This is something most UPS don't do but for this application you don't want the 60Hz sine wave to be broken. As long as the load is only a few milliamps of AC this should not be hard to do. -- Chris Albertson Redondo Beach, California __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
I took a look around at a few semiconductor manufacturers, and found an app note from Freescale (Motorola), on their MC3PHAC AC motor drive chip. It does use an external timebase of 4 MHz, but they only used a resonator, and this could be made way more precise. Though this is a 3 phase controller IC, they do make drives for smaller single phase motors, but I'm not sure who makes the controller IC's, nor do I know about any external time bases for them. It could be as simple as buying a surplus, single phase, AC motor drive, and setting it up for the correct speed, and adding a good timebase in place of a resonator. I have seen these types of drives sell for pennies on the dollar on ebay. It might be worth taking a look at. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 1:38 PM J. Forster wrote: John, I forgot to add, that an H bridge could work for a clock motor, since those are used to drive ac motors in industry every day. Yes, of course. You would have a sqauare wave though, unless it was modified. If I recall, that's the way a lot of the AC drives work today, using four sets of switching semiconductors, unless the motor is small enough to be ran off a power chip. In this case, I wonder how an AC drive would act if it ran a clock motor? The static inverters should not have issues with an induction motor. Set it at 60 Hz, and be done with it? Yes, but you have to get to the H bridge timing logic to do that. That's why you need the prints. -John === Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:55 PM J. Forster wrote: Certainly, the inverters can run that low, but if so they sing a lot. Best, -John = John, I didn't mean to say you said all that, just that the new inverters are cheap. I wrote that I thought some ran at around 1 kHZ, as I had an old one that did, and used a toroidal transformer in it. The new ones, as far as I am aware, are similar to the new-style switching power supplies, like the ones Maxim and a few others show in their app notes. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 12:37 PM J. Forster wrote: Chris, No I didn't say the output was 1000 Hz. No way. What I said (a bit amplified) was that the cheapie inverters use a high frequency, think 50 KHzish, DC-DC converter to make about 170 VDC, then use that to feed an H bridge, driven with either a square wave or a modified square wave, to make the output. You snmply need to vary that drive frequency to get 50, or 60, or any frequency you want. There is no output transformer. In fact, that is the cleverness of the design... no big, heavy, expensive magnetics. -John === As John mentioned earlier, the el-cheapo inverters are pretty much junk, and run as high as 1 kHz, if I recall. They were made to run small TV's, etc, that don't require a fixed line frequency, since they all have hot chassis now that don't use isolation transformers. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 11:55 AM Chris Albertson wrote: The reason for using 12 Vdc, is that you can pick them up, and 24 Vac CT transformer, on the cheap That's a good point.So use two of them. One to power a high current amp that produces a 12V AC signal from a high precision 60Hz input. Then the other to convert the 12V to 120V. This avoids the need for a high voltage DC power supply. Likely cuts the total cost in half at least. So just use use 12V supply to the amp and then a cheap 12V transformer connected backwards to step up to the desired voltage. The second advantage of this design is that you can connect a lead acid gell cell battery in parallel to the 12V DC supply and if the AC fails the battery will power the amp for a while. This way there is no switching so the 60Hz wave remains continuously even if AC mains fails. This is something most UPS don't do but for this application you don't want the 60Hz sine wave to be broken. As long as the load is only a few milliamps of AC this should not be hard to do. -- Chris Albertson Redondo Beach, California __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
An interesting question about making a 50/60 hertz source, Does a 120 to 12 volt transformer have enough inductance to use as a 12 to 120 volt transformer? Remember, the inductance is proportional to the square of the no of turns, where as voltage is proportional. cheers, Neville Michie ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Neville, Yes, it works just as well. I have seen companies use this to make tube bias supplies, when all the windings wouldn't fit on one transformer. They would use the filament supply, and tie the 6 or 12 volt coil of a smaller transformer to it, then use the 120 vac side as the bias supply. Also, they do something similar to this in making a double-isolation transformer, by just using two transformers tied together this way. There are losses, of course, I^2 R, etc, but it still works well in the end. The inverter I constructed, used a 24 vac, center tapped, transformer, making 12 Volts for each 1/2 coil, and fed the center tap with 12 Vdc. The switching transistors connect to each end of the winding, and merely switch the current to ground. It's really the same way they made the old vibrator supplies years ago, except they ran at a higher frequency so they could get the transformer size down for automotive radios. After that, they switched from vibrators to Germanium transistors to do about the same thing, except added bias windings. About all you need to add, besides the transistors, are snubbers to kill the spikes, and an oscillator/driver. Best, Will *** REPLY SEPARATOR *** On 6/26/2011 at 10:03 AM Neville Michie wrote: An interesting question about making a 50/60 hertz source, Does a 120 to 12 volt transformer have enough inductance to use as a 12 to 120 volt transformer? Remember, the inductance is proportional to the square of the no of turns, where as voltage is proportional. cheers, Neville Michie ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Yes. -John === An interesting question about making a 50/60 hertz source, Does a 120 to 12 volt transformer have enough inductance to use as a 12 to 120 volt transformer? Remember, the inductance is proportional to the square of the no of turns, where as voltage is proportional. cheers, Neville Michie ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
The C. S. Stong 'Amateur Scientist' anthology included a 110V 60 Hz telescope-tracking drive generator project that used a reversed filament transformer. It was a bleeding-edge design for the time, using a CK722 Wien bridge oscillator (complete with HP-style pilot lamp AGC) and a couple of early germanium power transistors. The author found that he had to rewind the transformer to cut down on saturation loss, but he was otherwise able to get it to work OK with the crude solid state technology available at the time. The author didn't say as much, but I wonder if transformers sold as 'filament' transformers were designed to saturate intentionally, to limit the inrush current they would otherwise apply to cold heaters. I would expect modern transformers to work better, just because their manufacturers are more concerned with minimizing losses than they were back in the day. -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Neville Michie Sent: Saturday, June 25, 2011 5:03 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS An interesting question about making a 50/60 hertz source, Does a 120 to 12 volt transformer have enough inductance to use as a 12 to 120 volt transformer? Remember, the inductance is proportional to the square of the no of turns, where as voltage is proportional. cheers, Neville Michie ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi- bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
Filament transformers do not saturate at normal input voltages. They only saturate if the peak flux, integral of VdT, exceeds the acceptable value for the core. What does limit the current is the voltage sag due to the properly scaled sum of primary and secondary leakage inductance plus resistance. -John '=== [snip] The author didn't say as much, but I wonder if transformers sold as 'filament' transformers were designed to saturate intentionally, to limit the inrush current they would otherwise apply to cold heaters. I would expect modern transformers to work better, just because their manufacturers are more concerned with minimizing losses than they were back in the day. -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Neville Michie Sent: Saturday, June 25, 2011 5:03 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS An interesting question about making a 50/60 hertz source, Does a 120 to 12 volt transformer have enough inductance to use as a 12 to 120 volt transformer? Remember, the inductance is proportional to the square of the no of turns, where as voltage is proportional. cheers, Neville Michie ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi- bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
John, A lot of it depends on the design of the transformer, or how close to saturation its core is ran, and the way the laminations are stacked. The inverters that were self-oscillating, and used tickler bias windings, depended on saturation to work correctly, and the transformer determined the oscillation frequency. If you're using a driver/oscillator, you don't need a saturating transformer, but since square waves might be involved, there is a different formula you use to design them. Also, you can make the stack, 1/2 butt stacked, and 1/2 interleaved. What I found in using a transformer, ran at a lower flux density, is the best to use in this, say around 10 kilogauss. I think some of the so-called filament transformers were designed with just enough iron in them to get by, and ran close to saturation to begin with. I de-rated the power on the inverter I built, and it was running a modified square wave, and I got by. Also, I've read that a triangle wave is good for this, or better than a sqaure wave. Now, I wouldn't have used the transformer I did with a pure square wave, as it most likely would need to be modified for use like the author found out. Take a look at Wikibooks for Transformer Design, and it tells a lot of info on this. Best, Will *** REPLY SEPARATOR *** On 6/25/2011 at 5:40 PM John Miles wrote: The C. S. Stong 'Amateur Scientist' anthology included a 110V 60 Hz telescope-tracking drive generator project that used a reversed filament transformer. It was a bleeding-edge design for the time, using a CK722 Wien bridge oscillator (complete with HP-style pilot lamp AGC) and a couple of early germanium power transistors. The author found that he had to rewind the transformer to cut down on saturation loss, but he was otherwise able to get it to work OK with the crude solid state technology available at the time. The author didn't say as much, but I wonder if transformers sold as 'filament' transformers were designed to saturate intentionally, to limit the inrush current they would otherwise apply to cold heaters. I would expect modern transformers to work better, just because their manufacturers are more concerned with minimizing losses than they were back in the day. -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Neville Michie Sent: Saturday, June 25, 2011 5:03 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS An interesting question about making a 50/60 hertz source, Does a 120 to 12 volt transformer have enough inductance to use as a 12 to 120 volt transformer? Remember, the inductance is proportional to the square of the no of turns, where as voltage is proportional. cheers, Neville Michie ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi- bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
