.@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 0H
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
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
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
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 pro
-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
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
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: [t
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 proportion
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. Als
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
___
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
I
> 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 fou
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
*
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 semiconduct
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 *
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
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
> 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 m
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 modifi
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 the
> 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 avoi
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 pla
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 schemat
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
uts@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 p
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
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
On Sat, Jun 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)?
Most comercial UPS are quite crude. Theu make square wave AC. In
you
-
From: Don Mimlitch
Sender: time-nuts-boun...@febo.com
Date: Sat, 25 Jun 2011 09:50:01
To: time-nuts@febo.com
Reply-To: Don Mimlitch ,
Discussion of precise time and frequency measurement
Subject: [time-nuts] No more 60Hz, How do I discipline 120VAC 60Hz from a UPS
I collect
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
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 (H
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