Re: [time-nuts] newbie question Thunderbolt supply
Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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] newbie question Thunderbolt supply
Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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] newbie question Thunderbolt supply
Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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. ___ 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] newbie question Thunderbolt supply
Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 9:38 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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. ___ 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] newbie question Thunderbolt supply
On 08/27/2012 10:09 AM, Jerry wrote: Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly A layer of Kapton (polyimide) tape would be electrically insulating but still conduct heat well enough for this application. You could then put a thermal pad under that and not have to worry about it being conductive or (I think) capacitative. I'd prefer the pad to the grease because the bottom of a PCB has lots of pointy bits that would keep the plane of the PCB spaced away from the plate, and thermal grease is not very effective as a filler material. It would also be springy enough to maintain contact with the bottom of the PCB. I'm still not entirely sure this is a good idea though, seems like a low-temp oven for the whole tbolt would be better if you want thermal stability. -- m. tharp ___ 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] newbie question Thunderbolt supply
There are components and traces. Bert In a message dated 8/27/2012 10:10:45 A.M. Eastern Daylight Time, jster...@att.net writes: Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 9:38 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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. ___ 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] newbie question Thunderbolt supply
Sorry I thought the discussion was about the bottom case of the TBolt, not the PCB, being in contact with a larger thermal mass. jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 10:44 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply There are components and traces. Bert In a message dated 8/27/2012 10:10:45 A.M. Eastern Daylight Time, jster...@att.net writes: Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 9:38 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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. ___ 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. ___ 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] newbie question Thunderbolt supply
On Mon, Aug 27, 2012 at 3:48 AM, ew ewkeh...@aol.com wrote: te and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren What happens if you flood the entire assembly in transformer oil? Aside from making a mess. Or look here: Thermal-Thermal_Pads_Tapehttp://www.frozencpu.com/cat/l2/g8/c487/list/p1/Thermal-Thermal_Pads_Tape.html -- 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] newbie question Thunderbolt supply
Hi It's probably easier to put the TBolt inside a sealed box along with a small /low speed / quiet fan. Let the moving air equalize everything. If vibration is a concern, mount the fan on some sort of isolators. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Monday, August 27, 2012 12:02 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] newbie question Thunderbolt supply On Mon, Aug 27, 2012 at 3:48 AM, ew ewkeh...@aol.com wrote: te and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren What happens if you flood the entire assembly in transformer oil? Aside from making a mess. Or look here: Thermal-Thermal_Pads_Tapehttp://www.frozencpu.com/cat/l2/g8/c487/list/p1/Th ermal-Thermal_Pads_Tape.html -- 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. ___ 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] newbie question Thunderbolt supply
There are thermal pads that are thermally conductive. You typically see them in laptops and, oddly, optical drives. They're usually one or two mm thick and very soft and squishy. Pull the bottom plate off any full-size optical drive and you'll probably find one or two pieces. I see lots of them on the auction site, but I have no personal experience with those. It looks like there's at least one or two that are available in large pieces and I saw thicknesses from 0.4mm up to 4.0mm. I wouldn't expect these to move heat nearly as well as a thin layer of thermal grease (which is itself a thermal insulator), but for some applications it works and is the only practical solution. Ed On 8/27/2012 10:12 AM, Bob Camp wrote: Hi The pad stuff is normally an insulator. It's not very stable, so there may be better alternatives. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 10:44 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply There are components and traces. Bert In a message dated 8/27/2012 10:10:45 A.M. Eastern Daylight Time, jster...@att.net writes: Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 9:38 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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. ___ 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
Re: [time-nuts] newbie question Thunderbolt supply
The thermal pads are, generally, electrically 'insulative' but heat 'conductive'. However, the screws that are usually used to mount the TBolt are metal and conduct electricity. Therefore, the main focus should be to transfer heat for the purpose of keeping the TBolt at a constant temperature. The transfer of electricity is secondary. The screws provide DC and AC conductivity and the pads augment AC conductivity. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Jerry Sent: Monday, August 27, 2012 9:09 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] newbie question Thunderbolt supply Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 9:38 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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. ___ 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] newbie question Thunderbolt supply
Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. In my opinion every thing else is an overkill. Working with very low noise PLL's I have found that getting rid of switcher noise is much easier than 60 Hz. There are other pin compatible alternatives to the TC7662A, even a 555 will work, just more components. Bert Kehren In a message dated 8/25/2012 8:10:07 P.M. Eastern Daylight Time, li...@rtty.us writes: Hi The easy way to do a TBolt supply is to start with something between 15 and 18 volts. Regulate down to 12 and 5 with linear regulators. 7805's are fine for the +5. Something like a LT1764 might be better for the +12. The -12 supply is very low current and does not matter much. People have had good luck with voltage inversion chips off the +15 and then something like a 79L12. Bob On Aug 25, 2012, at 6:41 PM, Edgardo Molina xe1...@amsat.org wrote: Dear Chris, Good afternoon. I am in the process of mounting my TBolt to a 2U 19 rack enclosure and was looking for a decent power supply. I found the Cisco unit and I am ordering a couple of them just in case. It would really be nice if I could have access to the diagram of the upgrade you did on yours to recreate the same performance from the Cisco unit. Please do not feel compromised if it is difficult to share. I didn't mean to be rude and if my note causes you any discomfort please kindly disregard it. I jumped into the thread because of experiencing the same doubts as the originator of it. Redondo Beach? I love visiting there whenever visiting my brother who lives in Rancho Palos Verdes. I would invite you lunch anytime just for the pleasure of meeting you in person. Thank you. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Aug 25, 2012, at 3:26 PM, Chris Albertson albertson.ch...@gmail.com wrote: On Sat, Aug 25, 2012 at 1:06 PM, Jerry jster...@att.net wrote: I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any performance loss if the +12vdc rail and the -12vdc rail are off by a few % in opposite directions, e,g +11.7 vdc and -12.3vdc ? The true nuts here on the time nuts list will tell you that the noise from a switching power supply is bad and that you need a regulated linear power supply. But for most practical purposes the Cisco supply is a good one. Being only slightly nuts myself. I use the Cisco supply but I built a small power adaptor board with matching connectors and some pi filters made with RF choke and capacitors. I realy don't thing the filters are needed but I wanted a connectorized installation and a small choke was as easy to solder in as a length of wire. -- 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. ___ 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] newbie question Thunderbolt supply
Hi The only real disadvantage of a 7812 / 340-12 is it's relatively high drop out voltage compared to a 1764 (or similar). Stability of any of them will be impacted more by thermal issues than anything else. The colder you can keep the 12V regulator, the more stable it will be. The +12 is by far the most sensitive supply line on the TBolt. Bob On Aug 26, 2012, at 6:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. In my opinion every thing else is an overkill. Working with very low noise PLL's I have found that getting rid of switcher noise is much easier than 60 Hz. There are other pin compatible alternatives to the TC7662A, even a 555 will work, just more components. Bert Kehren In a message dated 8/25/2012 8:10:07 P.M. Eastern Daylight Time, li...@rtty.us writes: Hi The easy way to do a TBolt supply is to start with something between 15 and 18 volts. Regulate down to 12 and 5 with linear regulators. 7805's are fine for the +5. Something like a LT1764 might be better for the +12. The -12 supply is very low current and does not matter much. People have had good luck with voltage inversion chips off the +15 and then something like a 79L12. Bob On Aug 25, 2012, at 6:41 PM, Edgardo Molina xe1...@amsat.org wrote: Dear Chris, Good afternoon. I am in the process of mounting my TBolt to a 2U 19 rack enclosure and was looking for a decent power supply. I found the Cisco unit and I am ordering a couple of them just in case. It would really be nice if I could have access to the diagram of the upgrade you did on yours to recreate the same performance from the Cisco unit. Please do not feel compromised if it is difficult to share. I didn't mean to be rude and if my note causes you any discomfort please kindly disregard it. I jumped into the thread because of experiencing the same doubts as the originator of it. Redondo Beach? I love visiting there whenever visiting my brother who lives in Rancho Palos Verdes. I would invite you lunch anytime just for the pleasure of meeting you in person. Thank you. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Aug 25, 2012, at 3:26 PM, Chris Albertson albertson.ch...@gmail.com wrote: On Sat, Aug 25, 2012 at 1:06 PM, Jerry jster...@att.net wrote: I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any performance loss if the +12vdc rail and the -12vdc rail are off by a few % in opposite directions, e,g +11.7 vdc and -12.3vdc ? The true nuts here on the time nuts list will tell you that the noise from a switching power supply is bad and that you need a regulated linear power supply. But for most practical purposes the Cisco supply is a good one. Being only slightly nuts myself. I use the Cisco supply but I built a small power adaptor board with matching connectors and some pi filters made with RF choke and capacitors. I realy don't thing the filters are needed but I wanted a connectorized installation and a small choke was as easy to solder in as a length of wire. -- 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. ___ 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
Re: [time-nuts] newbie question Thunderbolt supply
On 08/26/2012 02:07 PM, Bob Camp wrote: Hi The only real disadvantage of a 7812 / 340-12 is it's relatively high drop out voltage compared to a 1764 (or similar). Stability of any of them will be impacted more by thermal issues than anything else. The colder you can keep the 12V regulator, the more stable it will be. The +12 is by far the most sensitive supply line on the TBolt. Switcher to give a fairly stable voltage, filtered for noise and then linear stepdown for the last step. It's been done in high power audio amplifiers the last 20 years or so. Cheers, Magnus ___ 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] newbie question Thunderbolt supply
Having played with most combinations I could think of including the 1764 there is a lot to be said about the stability of the 7812 and mounting every thing on one plate since power dissipation of the OCXO decreases with increase in ambient temperature and current fluctuation is minimal since input from the switcher is very stable and 78 tabs are bolted to the aluminum plate. I am staying with 5 V regulator fed by 7812. Using battery backup changes every thing and I use a switcher for the 5V followed by a LDO and a separate switcher for the 12 V again followed by a LDO. Bert Kehren In a message dated 8/26/2012 8:09:03 A.M. Eastern Daylight Time, li...@rtty.us writes: Hi The only real disadvantage of a 7812 / 340-12 is it's relatively high drop out voltage compared to a 1764 (or similar). Stability of any of them will be impacted more by thermal issues than anything else. The colder you can keep the 12V regulator, the more stable it will be. The +12 is by far the most sensitive supply line on the TBolt. Bob On Aug 26, 2012, at 6:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. In my opinion every thing else is an overkill. Working with very low noise PLL's I have found that getting rid of switcher noise is much easier than 60 Hz. There are other pin compatible alternatives to the TC7662A, even a 555 will work, just more components. Bert Kehren In a message dated 8/25/2012 8:10:07 P.M. Eastern Daylight Time, li...@rtty.us writes: Hi The easy way to do a TBolt supply is to start with something between 15 and 18 volts. Regulate down to 12 and 5 with linear regulators. 7805's are fine for the +5. Something like a LT1764 might be better for the +12. The -12 supply is very low current and does not matter much. People have had good luck with voltage inversion chips off the +15 and then something like a 79L12. Bob On Aug 25, 2012, at 6:41 PM, Edgardo Molina xe1...@amsat.org wrote: Dear Chris, Good afternoon. I am in the process of mounting my TBolt to a 2U 19 rack enclosure and was looking for a decent power supply. I found the Cisco unit and I am ordering a couple of them just in case. It would really be nice if I could have access to the diagram of the upgrade you did on yours to recreate the same performance from the Cisco unit. Please do not feel compromised if it is difficult to share. I didn't mean to be rude and if my note causes you any discomfort please kindly disregard it. I jumped into the thread because of experiencing the same doubts as the originator of it. Redondo Beach? I love visiting there whenever visiting my brother who lives in Rancho Palos Verdes. I would invite you lunch anytime just for the pleasure of meeting you in person. Thank you. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Aug 25, 2012, at 3:26 PM, Chris Albertson albertson.ch...@gmail.com wrote: On Sat, Aug 25, 2012 at 1:06 PM, Jerry jster...@att.net wrote: I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any performance loss if the +12vdc rail and the -12vdc rail are off by a few % in opposite directions, e,g +11.7 vdc and -12.3vdc ? The true nuts here on the time nuts list will tell you that the noise from a switching power supply is bad and that you need a regulated linear power supply. But for most practical purposes the Cisco supply is a good one. Being only slightly nuts myself. I use the
Re: [time-nuts] newbie question Thunderbolt supply
On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. One of the advantages of generating waste heat like that is that you can but the heat to good use. I build a temperature controlled fan. It is very simple a temperature sensor IC connects to an opamp that drives a power transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and I can't see any RF on the DC using my old 365 Tek scope or by using a more sensitive RF power meter. 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] newbie question Thunderbolt supply
Hi all: I'm using buck regulators from our ebay friends, e.g. 130704328176 at a little over $1.00 apiece, settable to 5 v or 12 v or whatever, capable of 3 A with good heatsink. Foldback protection. Better than a 3-legged fuse, as my good gaffer Argus calls 'em. Don Bob Camp Hi The only real disadvantage of a 7812 / 340-12 is it's relatively high drop out voltage compared to a 1764 (or similar). Stability of any of them will be impacted more by thermal issues than anything else. The colder you can keep the 12V regulator, the more stable it will be. The +12 is by far the most sensitive supply line on the TBolt. Bob On Aug 26, 2012, at 6:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. In my opinion every thing else is an overkill. Working with very low noise PLL's I have found that getting rid of switcher noise is much easier than 60 Hz. There are other pin compatible alternatives to the TC7662A, even a 555 will work, just more components. Bert Kehren In a message dated 8/25/2012 8:10:07 P.M. Eastern Daylight Time, li...@rtty.us writes: Hi The easy way to do a TBolt supply is to start with something between 15 and 18 volts. Regulate down to 12 and 5 with linear regulators. 7805's are fine for the +5. Something like a LT1764 might be better for the +12. The -12 supply is very low current and does not matter much. People have had good luck with voltage inversion chips off the +15 and then something like a 79L12. Bob On Aug 25, 2012, at 6:41 PM, Edgardo Molina xe1...@amsat.org wrote: Dear Chris, Good afternoon. I am in the process of mounting my TBolt to a 2U 19 rack enclosure and was looking for a decent power supply. I found the Cisco unit and I am ordering a couple of them just in case. It would really be nice if I could have access to the diagram of the upgrade you did on yours to recreate the same performance from the Cisco unit. Please do not feel compromised if it is difficult to share. I didn't mean to be rude and if my note causes you any discomfort please kindly disregard it. I jumped into the thread because of experiencing the same doubts as the originator of it. Redondo Beach? I love visiting there whenever visiting my brother who lives in Rancho Palos Verdes. I would invite you lunch anytime just for the pleasure of meeting you in person. Thank you. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Aug 25, 2012, at 3:26 PM, Chris Albertson albertson.ch...@gmail.com wrote: On Sat, Aug 25, 2012 at 1:06 PM, Jerry jster...@att.net wrote: I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any performance loss if the +12vdc rail and the -12vdc rail are off by a few % in opposite directions, e,g +11.7 vdc and -12.3vdc ? The true nuts here on the time nuts list will tell you that the noise from a switching power supply is bad and that you need a regulated linear power supply. But for most practical purposes the Cisco supply is a good one. Being only slightly nuts myself. I use the Cisco supply but I built a small power adaptor board with matching connectors and some pi filters made with RF choke and capacitors. I realy don't thing the filters are needed but I wanted a connectorized installation and a small choke was as easy to solder in as a length of wire. -- 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.
[time-nuts] newbie question Thunderbolt supply
I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any performance loss if the +12vdc rail and the -12vdc rail are off by a few % in opposite directions, e,g +11.7 vdc and -12.3vdc ? Tia Jerry ___ 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] newbie question Thunderbolt supply
Hi As long as the +12 is stable a few percent isn't going to hurt anything. The -12 can be off by a few volts and everything will be fine. Bob On Aug 25, 2012, at 4:06 PM, Jerry jster...@att.net wrote: I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any performance loss if the +12vdc rail and the -12vdc rail are off by a few % in opposite directions, e,g +11.7 vdc and -12.3vdc ? Tia Jerry ___ 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] newbie question Thunderbolt supply
On Sat, Aug 25, 2012 at 1:06 PM, Jerry jster...@att.net wrote: I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any performance loss if the +12vdc rail and the -12vdc rail are off by a few % in opposite directions, e,g +11.7 vdc and -12.3vdc ? The true nuts here on the time nuts list will tell you that the noise from a switching power supply is bad and that you need a regulated linear power supply. But for most practical purposes the Cisco supply is a good one. Being only slightly nuts myself. I use the Cisco supply but I built a small power adaptor board with matching connectors and some pi filters made with RF choke and capacitors. I realy don't thing the filters are needed but I wanted a connectorized installation and a small choke was as easy to solder in as a length of wire. -- 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] newbie question Thunderbolt supply
Dear Chris, Good afternoon. I am in the process of mounting my TBolt to a 2U 19 rack enclosure and was looking for a decent power supply. I found the Cisco unit and I am ordering a couple of them just in case. It would really be nice if I could have access to the diagram of the upgrade you did on yours to recreate the same performance from the Cisco unit. Please do not feel compromised if it is difficult to share. I didn't mean to be rude and if my note causes you any discomfort please kindly disregard it. I jumped into the thread because of experiencing the same doubts as the originator of it. Redondo Beach? I love visiting there whenever visiting my brother who lives in Rancho Palos Verdes. I would invite you lunch anytime just for the pleasure of meeting you in person. Thank you. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Aug 25, 2012, at 3:26 PM, Chris Albertson albertson.ch...@gmail.com wrote: On Sat, Aug 25, 2012 at 1:06 PM, Jerry jster...@att.net wrote: I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any performance loss if the +12vdc rail and the -12vdc rail are off by a few % in opposite directions, e,g +11.7 vdc and -12.3vdc ? The true nuts here on the time nuts list will tell you that the noise from a switching power supply is bad and that you need a regulated linear power supply. But for most practical purposes the Cisco supply is a good one. Being only slightly nuts myself. I use the Cisco supply but I built a small power adaptor board with matching connectors and some pi filters made with RF choke and capacitors. I realy don't thing the filters are needed but I wanted a connectorized installation and a small choke was as easy to solder in as a length of wire. -- 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. ___ 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] newbie question Thunderbolt supply
I never made a diagram. All I did was solder down a terminal block to each end of a piece of prototype board. I connected the power lines using some small inductors I had and bypassed power to ground using (I think) 0.01 caps. I mounted the Cisco power supply block to the inside of the case using hot glue. As I remember the Cisco PS needs to have one line grounded to make it turn on. I figured that out when I got zero volts on the cable. On Sat, Aug 25, 2012 at 3:41 PM, Edgardo Molina xe1...@amsat.org wrote: Dear Chris, Good afternoon. I am in the process of mounting my TBolt to a 2U 19 rack enclosure and was looking for a decent power supply. I found the Cisco unit and I am ordering a couple of them just in case. It would really be nice if I could have access to the diagram of the upgrade you did on yours to recreate the same performance from the Cisco unit. Please do not feel compromised if it is difficult to share. I didn't mean to be rude and if my note causes you any discomfort please kindly disregard it. I jumped into the thread because of experiencing the same doubts as the originator of it. Redondo Beach? I love visiting there whenever visiting my brother who lives in Rancho Palos Verdes. I would invite you lunch anytime just for the pleasure of meeting you in person. Thank you. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Aug 25, 2012, at 3:26 PM, Chris Albertson albertson.ch...@gmail.com wrote: On Sat, Aug 25, 2012 at 1:06 PM, Jerry jster...@att.net wrote: I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any performance loss if the +12vdc rail and the -12vdc rail are off by a few % in opposite directions, e,g +11.7 vdc and -12.3vdc ? The true nuts here on the time nuts list will tell you that the noise from a switching power supply is bad and that you need a regulated linear power supply. But for most practical purposes the Cisco supply is a good one. Being only slightly nuts myself. I use the Cisco supply but I built a small power adaptor board with matching connectors and some pi filters made with RF choke and capacitors. I realy don't thing the filters are needed but I wanted a connectorized installation and a small choke was as easy to solder in as a length of wire. -- 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. ___ 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. -- 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] newbie question Thunderbolt supply
Hi The easy way to do a TBolt supply is to start with something between 15 and 18 volts. Regulate down to 12 and 5 with linear regulators. 7805's are fine for the +5. Something like a LT1764 might be better for the +12. The -12 supply is very low current and does not matter much. People have had good luck with voltage inversion chips off the +15 and then something like a 79L12. Bob On Aug 25, 2012, at 6:41 PM, Edgardo Molina xe1...@amsat.org wrote: Dear Chris, Good afternoon. I am in the process of mounting my TBolt to a 2U 19 rack enclosure and was looking for a decent power supply. I found the Cisco unit and I am ordering a couple of them just in case. It would really be nice if I could have access to the diagram of the upgrade you did on yours to recreate the same performance from the Cisco unit. Please do not feel compromised if it is difficult to share. I didn't mean to be rude and if my note causes you any discomfort please kindly disregard it. I jumped into the thread because of experiencing the same doubts as the originator of it. Redondo Beach? I love visiting there whenever visiting my brother who lives in Rancho Palos Verdes. I would invite you lunch anytime just for the pleasure of meeting you in person. Thank you. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Aug 25, 2012, at 3:26 PM, Chris Albertson albertson.ch...@gmail.com wrote: On Sat, Aug 25, 2012 at 1:06 PM, Jerry jster...@att.net wrote: I am using a Cisco supply 3 voltage supply for the T-bolt. Is there any performance loss if the +12vdc rail and the -12vdc rail are off by a few % in opposite directions, e,g +11.7 vdc and -12.3vdc ? The true nuts here on the time nuts list will tell you that the noise from a switching power supply is bad and that you need a regulated linear power supply. But for most practical purposes the Cisco supply is a good one. Being only slightly nuts myself. I use the Cisco supply but I built a small power adaptor board with matching connectors and some pi filters made with RF choke and capacitors. I realy don't thing the filters are needed but I wanted a connectorized installation and a small choke was as easy to solder in as a length of wire. -- 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. ___ 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] newbie question Thunderbolt supply
li...@rtty.us said: The -12 supply is very low current and does not matter much. Is the -12 used only for the RS-232, or is it also the negative supply to the DAC? If the latter, the regulation and noise may be important. I think I remember comments about it being used by the DAC. Wasn't there some mention of the TBolt working with a dead -12 supply, but only as long as the DAC output was above 0. -- These are my opinions. I hate spam. ___ 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] newbie question Thunderbolt supply
Hi The -12 runs the RS-232 and the negative supply to the DAC buffer. As long as it's past about -7V everything works pretty well. With no negative supply the DAC may have issues. Most of the OCXOs run right around 0V…. Bob On Aug 25, 2012, at 8:55 PM, Hal Murray hmur...@megapathdsl.net wrote: li...@rtty.us said: The -12 supply is very low current and does not matter much. Is the -12 used only for the RS-232, or is it also the negative supply to the DAC? If the latter, the regulation and noise may be important. I think I remember comments about it being used by the DAC. Wasn't there some mention of the TBolt working with a dead -12 supply, but only as long as the DAC output was above 0. -- These are my opinions. I hate spam. ___ 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] newbie question Thunderbolt supply
I think I remember comments about it being used by the DAC. Wasn't there some mention of the TBolt working with a dead -12 supply, but only as long as the DAC output was above 0. That was the conclusion. Actually the units these Thunderbolts were removed from used -7VDC instead of -12VDC. Many Thunderbolts will operate with the -12VDC line grounded but it shouldn't be left floating. It wouldn't be a good idea to run the Thunderbolt without some negative voltage on this line and where it's easy to find a triple output supply, why take the chance. The +12VDC is mainly for the oven and internal to the OXCO it goes to a +5VDC linear regulator for the oscillator circuit so the +12VDC isn't as critical as the +5VDC. -Arthur ___ 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] newbie question Thunderbolt supply
I would recommend a linear regulated supply rather than a 'switching' supply. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Arthur Dent Sent: Saturday, August 25, 2012 9:25 PM To: time-nuts@febo.com Subject: [time-nuts] newbie question Thunderbolt supply I think I remember comments about it being used by the DAC. Wasn't there some mention of the TBolt working with a dead -12 supply, but only as long as the DAC output was above 0. That was the conclusion. Actually the units these Thunderbolts were removed from used -7VDC instead of -12VDC. Many Thunderbolts will operate with the -12VDC line grounded but it shouldn't be left floating. It wouldn't be a good idea to run the Thunderbolt without some negative voltage on this line and where it's easy to find a triple output supply, why take the chance. The +12VDC is mainly for the oven and internal to the OXCO it goes to a +5VDC linear regulator for the oscillator circuit so the +12VDC isn't as critical as the +5VDC. -Arthur ___ 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.
