On the power supply hunt, and clone wars.. - Page 1
Forum section: electronics / general

author: lightning
author_rank: Newbie
timestamp: March 14, 2014, 05:39:08 am
content: Hi AllBefore I begin I must admit, sure I'm a newbie, but I readhttps://www.eevblog.com/forum/reviews/newbies-please-read-before-posting-24540/and I thoroughly searched the entire forum for an answer before I concluded I had to make this post. Similar questions to this one were posted before but not one that exactly answers my question, so here we are!In advance,thank you, all those who take the time to help me.So,I am looking for a DC power supply to test efficiency on sensitive electronics.12v-17v / 7a are the main ranges I would be using but it would be nice to have the wattage available at least around 250.The electronics I am dealing with are extremely sensitive so noise should be left to an absolute minimum and frequency/voltage/current as stable as possible. Not like Yihua (https://www.eevblog.com/forum/reviews/beware-yihua-yh-305d-bench-psu/) variable power supplies.The power supply should be linear, have power protection built in, and have a digital display. One output is sufficient, but as the saying goes, the more the merrier O0I know HP Agilent is pretty much Quality, Inc. but I wasn't looking to spend much more than $200.I was looking more at the likes ofhttp://www.mastechpowersupplies.com/regulated-power-supply-mastech-hy3010d.htmlbut heck if I know quality from cheap clones.What would you recommend if you were in my shoes?-Lightning

author: BravoV
author_rank: Super Contributor
timestamp: March 14, 2014, 05:45:51 am
content: Quote from: lightning on March 14, 2014, 05:39:08 amDefine the metric for the noise, stability and etc, people should able to tell if that budget is realistic or not to your requirement.

author: lightning
author_rank: Newbie
timestamp: March 14, 2014, 06:02:59 am
content: Quote from: BravoV on March 14, 2014, 05:45:51 amRipple & Noise 20 Hz to 20 MHzVoltage rms: preferable not too far from single digit mV (or low double digits)Voltage Peak-to-Peak: Less than 100 mVCurrent rms: preferable not too far from single digit mA (or low double digits)Readback Accuracy at 25°C ±5°CVoltage: Less than 1%, preferably closer to low double digit %Current: Less than 1%, preferably closer to midrange double digit % (or lower why not)Keep in mind the priority is rms goals over the readback accuracy goals.Thanks again so much for your interest to help me-Lightning

author: quarros
author_rank: Regular Contributor
timestamp: March 14, 2014, 09:00:48 am
content: Quote from: lightning on March 14, 2014, 06:02:59 amHiI have to ask: Is the high wattage an immediate need, or you just future-proofing? I ask this because most precision laboratory power supply that has really stable voltage/current regulation are usually not exceeding 5A in current. So at the moment I would advise you to hunt for two 6632B (or just one for start) on ebay and use them in parallel. Right now to my knowledge (which may mean nothing) it is your "cheapest" option considering your requirements. But if you're an American you could hunt for an old system power supply from HP / Agilient. There are a lot of these popping up all over ebay and some extremely cheap. Sorry for not being any more specific, or for reiterating the old mantra Agilient, Agilient, HP, etc...

author: lightning
author_rank: Newbie
timestamp: March 14, 2014, 09:10:16 am
content: Quote from: quarros on March 14, 2014, 09:00:48 amHi Quarros!Thanks a ton for lending your expertise and time to help me outHigh wattage is just future-proofing, probably actuallyneedcloser to 150watt. The 10A current is a must though.What is the closest power supply to meeting my requirements at under $200? (even if it's a bit more off than I'd specified earlier).Mantra Shmantra, it's all good hereThanks-Lightning

author: quarros
author_rank: Regular Contributor
timestamp: March 14, 2014, 12:31:38 pm
content: Quote from: lightning on March 14, 2014, 09:10:16 amOkay So.Please define your nationality or at least a continent. I'm asking this because most low noise power supply's are linear ones and that means it has a very heavy big transformer inside. So the shipping could amount as much as the buying price of the unit.But for example I saw this on ebay:http://www.ebay.com/itm/6653A-HP-Agilent-DC-Power-Supply-/271340949574?pt=LH_DefaultDomain_0&hash=item3f2d2e5046According to the datasheet it should fill the bill:http://cp.literature.agilent.com/litweb/pdf/5990-9305EN.pdfSpecification wise it is an overkill, but hey it is cheap now

author: robrenz
author_rank: Super Contributor
timestamp: March 14, 2014, 12:49:35 pm
content: If you live in the US get (2 or 3) HP6114A supplies and you can parallel them for the max amps you need. There is no lower noise higher stability higher precision power supply available.

author: Rigby
author_rank: Super Contributor
timestamp: March 14, 2014, 01:20:46 pm
content: Quote from: robrenz on March 14, 2014, 12:49:35 pmHe'd need 5 of them to get to 10A... You're right about the quality of these supplies, of course.Maybe there's a Power Designs model that would suit? I'm not as familiar with that make as I'd like to be.

author: quarros
author_rank: Regular Contributor
timestamp: March 14, 2014, 01:41:17 pm
content: I really hope you where the one who bought it lightning... It wasn't even 3 hours since I posted it.

author: lightning
author_rank: Newbie
timestamp: March 14, 2014, 07:34:04 pm
content: Quote from: Rigby on March 14, 2014, 01:20:46 pmrobrenz thanks for suggesting a solution for meAs Rigby said though I would need 5 of them which would bring my total to about $1k.Is there any unit maybe close to Aiglent quality and the specs I listed that is sufficient but not necessary the super expensive Aiglent?(How about Mastech HY3010D?)Quote from: quarros on March 14, 2014, 01:41:17 pmhaha, I'm American and I passed out because it was so late. I didn't buy anything yet! Still need the closest solution to what I'm loooking for in under $200. And lets not forget a digital screenAny ideas?

author: Rigby
author_rank: Super Contributor
timestamp: March 14, 2014, 08:50:30 pm
content: Those requirements and that budget... you'll find something eventually, but it will take time.1) High power2) Very low cost3) Quickly obtainablePick two; can't have all three.

author: quarros
author_rank: Regular Contributor
timestamp: March 14, 2014, 08:52:17 pm
content: Quote from: lightning on March 14, 2014, 07:34:04 pmI'm Sorry to hear... Well that's Life. The Powersupply I posted earlier was the perfect match for your required specs and it was 180 USD (500W 35V 15A Single output) but someone jumped on it. The only other advice I can give is to look for a similar Agilient "system power supply" (the ones for automated measurements, testing jig, no DC output at the front panel). These units can be bought a little above 200 USD. And have tight specifications for noise.I found one that may fit your criteria but this time I pm the details instead.

author: lightning
author_rank: Newbie
timestamp: March 14, 2014, 09:59:37 pm
content: Quote from: Rigby on March 14, 2014, 08:50:30 pmWhat's behind door number 2? and uhm, I'll pair that one with... door number 3!. Yes I'm sure.Thanks-Lightning

author: Rigby
author_rank: Super Contributor
timestamp: March 14, 2014, 10:11:00 pm
content: Didn't you say you wanted a 300W supply? That qualifies as high power. 20V @ 10A is still high as far as precision bench power supplies go, forget about affordable bench supplies.

author: lightning
author_rank: Newbie
timestamp: March 14, 2014, 11:26:14 pm
content: Quote from: Rigby on March 14, 2014, 10:11:00 pmAt least around 250 watt. But at this point I am willing to go to the bare minimum if that's the only way I enter the price range and general spec area I specified. The bare minimum would technically be 17V - 7A, or 119watt. The likely closest standard spec to this would be 20V - 10A, so 200watt. Any hope at this power level?In regards to the precision bench power supplies, Agilent averages at least 200% in price next to its competitors. Any reason why other brands such as Instek and Mastech have not been recommended for precision bench power supplies yet?Teh noob, I know.

author: robrenz
author_rank: Super Contributor
timestamp: March 14, 2014, 11:35:14 pm
content: I have a Mastech GPC3030D for many years that performs very well. I had to connect the front panel ground jacks to ground but other than that it performs very well including sub 2mV rms ripple.

author: Rigby
author_rank: Super Contributor
timestamp: March 15, 2014, 12:03:35 am
content: 20V @ 10A... I have two HP 6286A supplies that do this, and they go to 24V 12A, though not at the guaranteed performance necessarily (it depends on the line voltage, according to the manual.) They are not precision supplies, though. Agilent has the manual, check the specs and see if they meet your needs.