advice on the choice of bench power supply - Page 1
Forum section: electronics / testgear

author: arivel
author_rank: Regular Contributor
timestamp: August 03, 2021, 01:35:45 pm
content: Hello everybody.I would like to ask you for advice on choosing a laboratory power supply for my hobby but with the best quality-price ratio.it will be used to power TTL integrated circuits, CMOS,dual poweredoperational amplifiers (OPAMP), thyristors, optocouplers, relays ecc . Maximum Badget € 100Can you explain to me in a few words very briefly the advantages and disadvantages between the various types? For example linear, switching.So far I have visited the pages of the following brands without investigating much about them:Aplab-tekpower-mastech-voltaq-Korad-kaito-Dr-meter — dazheng-instekWhich would you choose among these?Hello and thanks

author: wizard69
author_rank: Super Contributor
timestamp: August 04, 2021, 06:04:59 pm
content: It really depends upon where you are at with your involvement in electronics. Personally I see the understanding of power supplies and their operation, as critical to becoming conversant in electronics. As such I strongly suggest building your own fixed voltage power supply to learn the basics of their design. Part of the reason I suggest this avenue is that one of the highest failure points in electronics is in the power supply section. So even if analog isn't your long term goal it really pays to understand the technology.As for the purchase of a supply, if your interest is digital systems in most cases a switching supply is fine. If you are dealing with op-amps it depends upon your goals but you may need very low noise analog supplies. In the end most labs end up with several power supplies, some homemade some purchased.Now when it comes to a brand it really depends upon what you believe about their quality. Your best bet here is to find a few models to consider and then read any legitimate reviews you can find.Quote from: arivel on August 03, 2021, 01:35:45 pm

author: J-R
author_rank: Super Contributor
timestamp: August 04, 2021, 09:58:48 pm
content: I propose the Korad KA3005D:https://www.amazon.com/KORAD-KA3005D-Precision-Adjustable-Regulated/dp/B0084JFWNYA few years ago when I jumped back in to electronics I picked up some of these and some other inexpensive linear supplies. I think the interface is the best compared to the other "knob" interfaces and the accuracy has been quite good. Older versions had a loud fan but my understanding is that they've fixed that in the latest versions. Maybe someone else can chime in? In my case I replaced the fans with ones with a temperature sensor glued to the heatsink.Don't get the Korads with the interface where you push the knob for coarse/fine and also avoid the supplies with separate coarse/fine knobs. For frequent use they are a pain in the neck to use. If you're just going to set the supply to 5V and leave it all day, then I suppose it won't matter...

author: JDBoyd
author_rank: Newbie
timestamp: August 07, 2021, 04:12:35 pm
content: Korad KA3005D seems like a fine place to start for many people. However, since the original asker mentions "dual powered operational amplifiers", I suspect a 2 or 3 channel supply would be a better fit for not a lot more money than buying two of the KA3005Ds. The Siglent SPD3303X-E caught my eye, but at the time I ended up getting the KA3005D simply because it would arrive much sooner.

author: arivel
author_rank: Regular Contributor
timestamp: August 07, 2021, 07:55:30 pm
content: let's start by putting some stakes.linear power supply (no switching).central output connected to the central socket of the transformer, not to the casing.

author: masterx81
author_rank: Frequent Contributor
timestamp: August 07, 2021, 09:31:07 pm
content: I have a korad ka3305p. Dual independent supply, plus a 5v fixed output. Does the job.

author: arivel
author_rank: Regular Contributor
timestamp: August 08, 2021, 12:44:05 pm
content: thanks for the replies.other requirement:passive heat sink. no fan

author: arivel
author_rank: Regular Contributor
timestamp: August 11, 2021, 07:07:54 am
content: Hello.I have two things to ask you.I noticed that there are power supplies that have acronyms such as PS305D or S-LS-33 in common with different brands. What does this mean ? . do these abbreviations identify a specific type of power supply?.apparently there are no single channel power supplies with output connected to the central socket of the transformer to obtain dual power supply.therefore there can be two solutions.1) take a two-channel power supply2) take two power supplies equal to one channel to be connected in series.it seems that a separate network ground terminal is required to achieve this, do you confirm?

author: masterx81
author_rank: Frequent Contributor
timestamp: August 11, 2021, 09:25:40 am
content: 3005 305 = 30v 5aS-LS-33 = 30v 3a3305 = 30v, 3 ch, 5a.etc.If you want dual supply you need or 2 units or a dual channel unit, and connecting externally the outputs. In most supply the outputs are floating, also on dual channel units. So that you can combine them. For example the korad 3305 allow to connect them in series or parallel via a simple press of a button (for 60v 5a or 30v 10a output). Instead if you want a +/- output you need to bridge them externally.And good luck finding something without fan, the choice will be very limited. Also smps units (so with high efficiency) have fans, linear is way more difficult.

author: arivel
author_rank: Regular Contributor
timestamp: August 27, 2021, 10:54:21 am
content: I found these:some exceed the established budget, albeit slightlyhttps://www.pce-italia.it/html/dati-tecnici-1/alimentatore-tavolo-pkt-1540.htmhttps://accusrc.com/product-Topward-3303D-7980#:~:text=Topward%203303D%20for%20sale%20%24129.00%20%7C%20In%20Stock%20%7C%20AccuSource%20Electronicshttps://www.komerci.de/shop/stromversorgung/Labornetzgeraete/qj3005e-pk-labornetzgeraet-regelbar-30v-5a-passiver-kuehlunghttp://www.signalhawk.in/DC_Power_Supplies.pdfhttp://china-mch.com/web/index.php?topclassid=16&classid=104&id=99&lanstr=en&wap=1having a compact power supply with two 5V and 0-30V outputs could be useful.is there anyone who has had experience with the last two? .i would be curious to know how they are.of this the first on the lefthttp://www.signalhawk.in/DC_Power_Supplies.pdf

author: wizard69
author_rank: Super Contributor
timestamp: August 28, 2021, 06:46:42 pm
content: I have no experience with any of the items links I followed. It looks like the SignalHawk is built in India and frankly that would be motivation as I believe the world needs to curtail business with China as much as possible. I have no idea what the quality is like for the SignalHawk but then again I have no idea with respect to the rest. That being said there is always issues at the low end.One thing to look out for, on the low end, is that the output connectors are on a proper 3/4" pitch. This is one unexpected curve that you need to watch out for with items form China.As for your desire for a passive heat sink, I really think that such a requirement is a mistake. Even a switching supply would benefit from a fan. With modern controls and fans the noise level would be pretty low. I'm not saying passive cooling is impossible but it would result in a larger device with a larger heat sink. A fan just allows for the compact supplies, even switching supplies, most people want these days.Quote from: arivel on August 27, 2021, 10:54:21 am