What is the best PPSU? - Page 1
Forum section: electronics / beginners

author: MMDuino
author_rank: Regular Contributor
timestamp: July 16, 2016, 08:31:25 am
content: Hello everyone,For the beginners "like me" what I should buy of those guys (SIGLENT-SPD3033X, RIGOL-DP831 or OWON ODP3032)?...Thanks in advance

author: bitseeker
author_rank: Super Contributor
timestamp: July 16, 2016, 10:39:14 pm
content: There is much to choose from when it comes to power supplies. The "best" is the one that fits your needs, because almost everything has tradeoffs (more does not necessarily mean better).So, what do you need it for and what's your budget? Even as a beginner, there are likely a few things you have in mind that you plan to build, test, fix, etc. It's not cost-effective to buy for every conceivable project from the beginning.

author: rstofer
author_rank: Super Contributor
timestamp: July 16, 2016, 11:57:19 pm
content: I'm pretty sure I prefer the Rigol DP832 to the DP831. Buy the 832 and hack it to get the features of the 832A. The process is well understood.That is, if even having a bench power supply makes sense. I've been doing this a LONG time without one and I might buy one next month. But I want it specifically as an instructional aid to a budding EE. For my own purposes, well, I haven't had one in 60 years, I'm not sure I absolutely need one now.There are fixed voltage linear supplies available. There are hundreds of DIY projects. There are even wall warts - except switching power supplies are noisy. Lots of alternatives.

author: Brumby
author_rank: Unknown
timestamp: July 17, 2016, 03:48:42 am
content: I was without a bench PSU for many years also. Got by with plug packs and multi-tap transformers. Then one day I picked up an Altronics kit for one. A few years later I built it. It's the same unit that has appeared in the background of Dave's videos (which is missing the knob for the current limit pot) - before his last move.Calibration of the internal metering isn't brilliant - and maybe one day I'll get inside it to fine tune that - but it's good enough for day-to-day. Having one around, however, just makes life SO much easier.... and you may find yourself reaching for it more often than you might have thought.

author: julian1
author_rank: Frequent Contributor
timestamp: July 17, 2016, 06:35:15 am
content: I followed Dave's advice and use these,What I like most is no fan noise!.Also, simple linear design, full schematics are available, CV and CC, and reasonably priced.

author: MMDuino
author_rank: Regular Contributor
timestamp: July 17, 2016, 07:07:21 am
content: Thank you so much for your reply,Due to the bad Electrical system conditions we have it here I'm trying to build a small Electronics projects such as a Protection circuits for the Air Conditioners Split Type, Refrigerators, Freezers and most of the home appliances, as you know it's difficult to get work here and i'm trying to get out of the hole...so I need a power supply with resolution up to 1 mV, 1 mA as well as with a negative source to be hooked up to the negative pin of the OpAmp TL074 (This IC will be used in my projects) to let me configure my circuits as I need/want...Thank youQuote from: bitseeker on July 16, 2016, 10:39:14 pm

author: R005T3r
author_rank: Frequent Contributor
timestamp: July 17, 2016, 11:19:27 am
content: Without thinking twice, I bought an agilent U8002A, 0-30V 5A, and it's a very fitting choice for my needs(I've saved up 6 months). I recommend you to take a look also at other brands as well.I've learn that cheap lab instrumentation is probably not worth buying unless you know what to expect from it (bugs included). I mean, if you look other topics, a lot of users are experiencing issues with "cheap instruments" (yep, power supply included). I tell you this because there are a lot of "traps" out there when making your own projects. If you can't trust your instruments, you have a bigger problem to solve: device related problem? Instrument related problem? you will ever have that doubt. So, my advice would be: save up and buy yourself a good power supply, you won't regret it: a good instrument lasts forever, a bad instrument lasts 6 months!.I'm not saying you should buy ultra high end instruments,(such as keithley SMUs): it's not the right tool for your needs. Stick to a good brand and a good and reliable product and care about features specifically for your needs

author: jpb
author_rank: Super Contributor
timestamp: July 17, 2016, 12:15:44 pm
content: I've been very happy with my TTi PL320QMD but am looking at getting a second supply as well (two channels isn't enough for some of my experiments). But there is a huge range of options and trades off to consider.I like simple linear supplies as efficiency doesn't really matter for a bench supply and neither does weight really but size is a bit of a drawback and they are less flexible in distributing voltage/current between outputs than some of the post-regulated switched mode ones.Prices for good brands (R&S, Keysight, TTi) are pretty steep as well.My personal order of priority is something like:Low ripple/good stabilityClear readout of I and VBoth current and voltage limitingRemote sensing for Voltage (though to be honest, I tend to be too lazy to connect this up)Small and neat (as possible - given all the above)Not too eye-wateringly expensive.low fan noise or preferably no fan at all.I'm less bothered aboutremote controlarb outputability to fit in a 19inch rackefficiency

author: bitseeker
author_rank: Super Contributor
timestamp: July 18, 2016, 07:26:43 pm
content: Quote from: MMDuino on July 17, 2016, 07:07:21 amVery good. So, it sounds like you don't need a lot of current. What about voltage? Probably a maximum of 15V or 30V?If you must buy new, then the ones you listed will likely work well for you, but for the Rigol take a look at the DP832 instead of the 831. If you have access to used gear, that's often a cost-effective way to acquire power supplies. I have several power supplies in my home lab, only one of which I purchased new.Regarding resolution, although it's great to have single mV- and mA-level display, it often costs more. Many power supplies provide fine output control, but do not display it, so you could just use a DMM to see more resolution and save some money in the process (i.e., cost vs. convenience). In the case of the DP832, there's a hack to enable the high-resolution display.

author: MMDuino
author_rank: Regular Contributor
timestamp: July 18, 2016, 07:41:46 pm
content: Quote from: bitseeker on July 18, 2016, 07:26:43 pmThanks for your reply...Unfortunately I don't have a precision DMM to read mA or mV, and for the Rigol DP831 I'm trying to get one (to be PPSU and Precision DMM at same time) with original high resolution update to get 2nd ch for a -+3.300 V to be accurate supply as a VCC, then the 3rd ch to play with it on the negative pin of the OpAmp and finally 1st ch to be applied on the Positive pin of the same OpAmp, as a result I can make a comparator amplifier to be as a sensor for the 220 VAc after putting 3 Mohm resistor in the front.

author: bitseeker
author_rank: Super Contributor
timestamp: July 18, 2016, 08:47:36 pm
content: Yes, that will work. My recommendation, though, would be to buy a less-sophisticated power supply (fewer features, etc.) and get a high-resolution DMM. There will be more to measure in your projects than just the supply rails, so the DMM is more critical than a precision supply. You'll want your circuit to be able to tolerate less than perfect power, anyway.

author: Kilrah
author_rank: Unknown
timestamp: July 18, 2016, 09:19:33 pm
content: If you're looking at low cost and constant current isn't your main concern I'm pretty happy with this:https://www.eevblog.com/forum/testgear/tekpower-tp3016m-handheld-power-suppy/

author: MMDuino
author_rank: Regular Contributor
timestamp: July 19, 2016, 09:07:20 am
content: Quote from: Kilrah on July 18, 2016, 09:19:33 pmThanks for your reply, there are 2 disadvantages of this Power Supply:1- This is a SMPS and it will be noisycomparing with the Linear Programmable power supplies.2- It's still out of my requirement, it has only 10 mV resolution!.Thanks again

author: Kilrah
author_rank: Unknown
timestamp: July 19, 2016, 09:30:53 am
content: Quote from: MMDuino on July 19, 2016, 09:07:20 amI was building upon the previous poster's suggestion that you use some of the savings from one (or more) cheaper PSU(s) to buy a decent multimeter or 2. You won't go far if the only thing you can measure is the supply.I have a hard time understanding why you'd need a super super clean and hugely precise PSU just to power an opamp...

author: bitseeker
author_rank: Super Contributor
timestamp: July 19, 2016, 03:29:51 pm
content: MMDuino,I'd say there are a couple of ways for you to proceed.1. Get one of the three power supplies you originally listed, if at least one of them meets your desired specifications. Any of them will likely be more than enough.2. Review the datasheets of the components you'll be using and choose the supply that meets or exceeds the power requirements of those components and satisfies your desired specifications.To refine the choices beyond this would require diving much deeper into the the many characteristics of power supplies and their associated trade-offs, which could keep you undecided for a while. It's better to get going on your projects and gain experience that will inform your future equipment choices.For example, one of my precision power supplies provides 20V and 1A with an almost-nonexistent ripple voltage of 0.1mV peak-to-peak (vs. 2mVpp and 0.35mVrms on the DP832A) and voltage selection resolution of less than 0.05mV (vs. 1mv on the DP832A). And it has no fan!However, current selection resolution is only 10mA, the display resolution is only 250mV and 10mA, and it has only one output.So, why did I choose it? Well, I rarely operate a power supply in constant current mode, so precision current control is not important to me. My DMM can display voltage down to 0.0001mV, so display resolution on the power supply is not important beyond being able to see that it is still operating near the desired settings. I have a non-precision triple-output supply for general purpose use, so this one is for precision voltage purposes. Schematics and parts are readily available, so it's easy to repair if something goes wrong. It has an amazingly cool user interface, so I get some visual enjoyment from its aesthetics, even when it's not on. And it cost me less than $100, so I can devote funds to more important or more variety of tools and equipment.

author: MMDuino
author_rank: Regular Contributor
timestamp: July 19, 2016, 04:01:05 pm
content: Quote from: bitseeker on July 19, 2016, 03:29:51 pmReally you start to change my directions/thinking about my requirements for the PPSU,,,Beside that, Yesterday I faced another problems(with my design) that I should have an AC power supply/Source or VARIAC to control the 220 vAc...anyhow, there is a lot of money should be spent to get a precision, practical and active design...Thank you again...

author: bitseeker
author_rank: Super Contributor
timestamp: July 19, 2016, 05:18:15 pm
content: You're welcome. Regarding AC power supplies, if you just need different AC voltages, a variac/autotransformer is sufficient. I assume you'll be using it to simulate less than perfect mains voltage levels. A true AC power supply is much more expensive because it will usually enable you to select a variety of output frequencies, in addition to voltage. For standard 50 and 60 Hz, a variac is fine.