WANTED: Power supply in mv steps - Page 1
Forum section: electronics / general

author: SirDan
author_rank: Contributor
timestamp: December 10, 2011, 08:49:54 pm
content: Can anyone recommend a power supply that can output low voltage in millivolts? Minimum output can be as high as 40 mv but would like in 5mv or better resolution. 1mv resolution is desirable.Thanks,

author: requim
author_rank: Regular Contributor
timestamp: December 13, 2011, 08:38:20 pm
content: Not sure that I'd recommend this (only because I have no experience with it) but this should do the trick:http://www.ebay.com/itm/PD-Power-Designs-model-2005-Precision-Power-Source-DC-Power-Source-/350496915310?pt=LH_DefaultDomain_0&hash=item519b3e7f6e#ht_7693wt_1185I'd suggest searching eBay using "precision power source" or something similar that should at least give you a starting point from which to identify what's out there.You didn't mention what voltage range(s) you're looking to cover so I'm assuming you need low voltage. If you can stand having 10 mV steps I'd recommend one of the Agilent/HP e3600 series power supplies (e3610, e3611, e3612, e3613, e3614, e3615, e3620, e3630, e3631, ... ) I have a few of them and they are excellent. You can find them on eBay for a song and a dance if you are patient.

author: Short Circuit
author_rank: Frequent Contributor
timestamp: December 13, 2011, 09:33:45 pm
content: My Keithley 2304A apears to do 5mV steps all the way from 0V (controls imply 1mV resolution, but output changes only every 5mV change).

author: tinhead
author_rank: Super Contributor
timestamp: December 13, 2011, 10:45:32 pm
content: No idea what max. voltage (well, you can use two PSUs in series - one for offset one for extra steps with 10:1 dividerto increase resolution), but consider something like that :10mV resolution with 2000 steps -> Rohde & Schwarz NGPV, e.g. ebay item 270633865279Sure you need GPIB to control it, but the commands are very basic, a simple whatever based (e.g. FTDI) controller is enough.

author: SirDan
author_rank: Contributor
timestamp: December 15, 2011, 05:32:23 am
content: Thank you to all that replied. Ordering one from ebay as suggested.Best Regards,

author: bfritz
author_rank: Regular Contributor
timestamp: December 15, 2011, 05:41:16 am
content: It may be too late, but...B&K 915x series seems to have plenty of resolution.http://www.bkprecision.com/products/docs/datasheets/915x_datasheet.pdf

author: requim
author_rank: Regular Contributor
timestamp: December 18, 2011, 09:20:31 am
content: Yeah those BK Precision supplies definitely appear to have the precision. I probably should have posted that the Agilent 6600 series power supplies do at least 1mV resolution as well but those are quite expensive. Suppose I should have asked what your budget was. Oh well..Out of curiosity which power supply did you end up ordering?

author: amspire
author_rank: Super Contributor
timestamp: December 18, 2011, 11:58:01 am
content: There is a different approach to this.Go after one of the Fluke 42XX programmable precision power supplies.They include a Fluke 14 bit accurate D/A with something like a 16 bit adjustment precision. So on the +/-16V range, they have a 1mv step size. On the +/- 64V range, they have a 4mV step size.They are 4 quadrant fast bipolar supplies which means they can output both positive and negative voltages and they can sink or source current. The settling time to 0.01% is something like 100uS.They often sell pretty cheaply as they have one tiny little problem - no control panel. The control is via a simple parallel data connection on the back, so if you are prepared to make your own control panel, you can get a bargain. Some have the optional GPIB instead of the parallel interface. There is a Fluke control panel available, but it is not hard to make something better with today's components. The smaller models are 100mA. The larger models are 1A. Some are binary (the one I prefer), and some are binary coded digital.The BCD models are the 4210A (100mA), 4250A(1A) and the 4270A(0.5A +/-99.99V maximum)The Binary models are the 4216A(100mA), 4265A(1A) and the 4275A(0.5A 0.0005V steps on low range, +/-110V maximum).If anyone is interested, here is the spec sheet for the series:http://www.slack.com/Spec/Fluke4275A.pdfI seem to remember that although the BCD are spec'ed to go to 9.999V (or whatever the range goes to), you can send hex to the decades which means you can get over 16V out on the same range if you want to.Not the greatest general purpose power supply, but if you want something that is super stable, very fast, that can sink or source, and that sometimes are available very cheaply, these are an interesting option.Richard

author: SirDan
author_rank: Contributor
timestamp: December 21, 2011, 11:47:40 pm
content: Thanks again to everyone that replied, all good suggestions. I ended up winning a bid on a Power Designs power supply that does millivolt steps. Paid $75.00 + shipping.http://www.ebay.com/itm/PD-2005A-Calibrated-Precision-Power-Source-/130617359398?pt=LH_DefaultDomain_0&hash=item1e6966bc26Scroll down a bit.

author: Unknown
author_rank: Unknown
timestamp: December 22, 2011, 12:03:51 am
content: Looks like a good find at a fairly low price.

author: requim
author_rank: Regular Contributor
timestamp: December 22, 2011, 12:54:25 am
content: Nice find. That should definitely do the trick. I don't think there are too many power supplies you can find for less that will do mV stepping. Congrats.

author: tekfan
author_rank: Frequent Contributor
timestamp: December 22, 2011, 04:58:23 am
content: That looks like a later model of this supply:http://amplifier.cd/Test_Equipment/other/2005.htmlVery nice retro design with a temperature controlled zener reference.

author: saturation
author_rank: Super Contributor
timestamp: April 01, 2012, 05:53:40 pm
content: An amazing supply. I regret not hearing about them during their prime.See more here:https://www.eevblog.com/forum/general-chat/what-is-a-good-power-supply/msg101788/#newQuote from: tekfan on December 22, 2011, 04:58:23 am

author: bingo600
author_rank: Super Contributor
timestamp: April 05, 2012, 04:53:29 am
content: Just bought 2 of theseHP 6632Bhttp://www.ebay.de/itm/220975363992Havent received them yet , but they wouldfit the requirement/Bingo

author: saturation
author_rank: Super Contributor
timestamp: April 05, 2012, 01:03:16 pm
content: Congratulations! I just bought several Power Designs precision models.I just received one, and given they are mostly 30-40 years old, its going through a lot of testing.But here's some interesting tidbits:While its step voltage adjustment is mV, it can be easily adjusted to 1uV precision, it could be more but my DVM are stable only to 100nV with difficulty. Its as stable as a calibrator. 24 hour drift is 20 ppm! Under DC loads to 1A, its can hold uV stability, dial in accuracy and settles quickly under simple dynamic load tests [ parallel resistors of 10 ohms connected intermittently]; I haven't had a chance to time it yet on a scope.The linearity problems discussed by amplifier.cd and rako.com could most likely be dirty contacts on the dial. Repeat action and blow cleaning has improved mine, its still in cal after over 30+ years.Compared to the qualities on stand alone supplies available today, even the spec sheet of the E36xx series by Agilent, these Power Designs are, to date, orders of magnitude better in stability, accuracy and regulation.I paid $25 for it, and $50 for the others.Quote from: bingo600 on April 05, 2012, 04:53:29 am