First power supply - Page 1
Forum section: electronics / beginners

author: Zynch
author_rank: Newbie
timestamp: March 02, 2021, 12:11:04 pm
content: HelloSo I know this was probably asked a million times already but here I am with another one.I’m starting to equip my home lab and looking to buy a bench power supply. I really don’t know what to get and am looking for some help.I’ve read a few posts here but it’s not helping much.I work with absolutely anything from microcontrollers, led strips (not going for crazy lengths that require insane amps), stepper projects and random industrial automation stuffWhat I’m looking for:- at least 24 V output to cover my 3d printer and random industrial automation components- 3 - 5 A would probably suffice for notprobably no more than 1 output, if there are more, they can be fixed 5/12 V- if it has connectivity (rs232, usb, ethernet, …) it could be fun to play with in the future- a decent user interfaceAt the moment I’m looking at what TME (tme.eu) has on offer, as I have a couple of things I’m looking to order from them already, otherwise anything that I can order from within the EU without getting extorted with shipping works.Budget: about 150€ before taxI'm not looking to spend too much, but am willing to pay more if there is someting good quality that will last

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 02, 2021, 12:26:33 pm
content: This is the one I snap bought when I didnt know anything at all.I remember Dave from eev blog says he hates these twin course and fine knob power supplies and theres cooler one's that have a winder instead that dials it and its better to control... and I agree with him, the fine knob doesnt seem to make barely any difference at all, and u have to sit there a while just tweaking it a micrometre overshooting up and down until you get it right.I'm probably going to step up to a better one soon.What would be good for my next one->* ac output, (I ended up making a marx generator cause I was stuck with dc so long! but it forces you to learn how to make your own oscillators, so maybe its good going without it as a beginner.)* more volts. (If u can have a power supply put out 500 volts, then u can get spark gaps to work without even using a doubler or a transformer.)Trap for young players->Theres a strange thing that happens if you power a circuit with not enough resistance and heaps of parallel pathways, the power supply will not output full voltage, because it hasnt got enough watts to hit the amp/current requirement, thats one of the first things you have to learn, that the current is the maximum current, it doesnt necessarily get to it, and if you are undershooting your watts, itll actually put out less current than what is designated.If im saying anything wrong now, I will stand a n00b corrected.BTw ive never shocked myself with this power supply by itself, but the marx generator did and the capacitors did.One way to give yourself a nasty shock is just in turn charge up a heap of capacitors in series and grab both ends.

author: andersthuresson
author_rank: Contributor
timestamp: March 02, 2021, 03:29:58 pm
content: I got a Riden from AliExpress together with the most powerful switching power supply I could find. It's 60V / 12A. The nice thing is that you can pick and choose a cheaper switching power supply to get the cost down. This is the most powerful power supply I have. Time will tell if the quality is good but the built of the thing seems just fine.

author: larsdenmark
author_rank: Regular Contributor
timestamp: March 02, 2021, 03:45:24 pm
content: Anything you spend on thing with serial, USB, GPIB interface will take things away from safety, sturdiness and other important features, but it shouldn't be impossible to get.This is bare minimum (68€):https://www.reichelt.com/dk/en/laboratory-power-supply-unit-0-30-v-0-5-a-stabilized-kd3005d-p148149.htmlWith USB (93$):https://www.reichelt.com/dk/en/laboratory-power-supply-unit-0-30-v-0-5-a-stabilized-pro-kd3005p-p148150.htmlI own a Manson (this one has USB, 199€)https://www.reichelt.com/dk/en/programmable-laboratory-power-supply-unit-with-usb-interface-hcs-3202-p106617.htmlNote that Korad, Manson and many other power supply "brands" are made by someone else and are sold by many names. Personally I would avoid the Korad as there are way too many stories about lack of quality.

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: March 02, 2021, 03:48:14 pm
content: I bought this one, it really works very well.

author: ledtester
author_rank: Super Contributor
timestamp: March 02, 2021, 04:16:05 pm
content: QuoteJust wanted to chime in here to say that you should get a dedicated supply for your 3d printer. It has fixed requirements. It doesn't need adjustable voltage or current or displays. Besides, you don't want to tie up your only power supply when you are running your 3d printer (for hours and hours at a time.) A fixed supply can be very cheap compared to an adjustable bench supply.

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: March 02, 2021, 04:48:30 pm
content: How vital is it to get a power supply that is grounded to mains? I.e. with a 3 pin plug.

author: ledtester
author_rank: Super Contributor
timestamp: March 02, 2021, 05:12:20 pm
content: Quote from: YurkshireLad on March 02, 2021, 04:48:30 pmFor development / experimentation you generally want your supply to be floating -- not grounded -- as that is the most useful configuration.However, a supply may use a 3-prong plug if it has exposed metal. That metal needs to be grounded for safety.So, a 3-prong plug is not an indication that the supply itself is grounded.

author: Zynch
author_rank: Newbie
timestamp: March 02, 2021, 07:50:00 pm
content: Quote from: ledtester on March 02, 2021, 04:16:05 pmI'm not crazy, my printer has it's own dedicated supply (24V, 17A), it was meant as testing parts for it.Quote from: larsdenmark on March 02, 2021, 03:45:24 pmThat's why I wrote it as "if it has connectivity" since it's not really needed just a nice bonus to play around with (which I probably won't touch for years tbh).The more I look the less I know and question what I should even look for and how much I wanna spend.This is gonna be a big choosing session.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: March 02, 2021, 10:36:58 pm
content: Here is just a suggestion:Get an used old variable PS with a big transformer and analog meter readout. The heavier the better.However the analog meters are not always accurate but you can always use a good multimeter to verify volts.Might save you some money and give you a starting point. for maybe 10 euros. (they are cheap in the US, I would think they would be cheap where you are)If you don't like it, you can always use it to power your small electric train! HA!I have several variable PS including a 0-40 v monster HP 6268B (600 watt?) 40 kilo weight.I use my 3 output digital display power supply sometimes.I frequently use my one output old cheap Leader analog meter PS.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 03, 2021, 12:17:51 am
content: Quote from: larsdenmark on March 02, 2021, 03:45:24 pmDifferent experience here.Have had a Korad running great for over 7 years, liked it so much I bought a second unit recently for another location. Many, many more happy users than unhappy users, I believe. KA3005D/P has a very nice user interface; accurate to roughly 10mV and 1-2 mA (can be calibrated without opening the unit); good price. Not perfect but for ~$100 it's hard to see what's better.https://uk.farnell.com/multicomp-pro/mp710503/bench-power-supply-1ch-adj-5a/dp/3410526?st=tenma%20ka3005d.... or Korad or Tenma KA3005Dall made by Korad, I thinkhttps://eleshop.eu/korad-ka3005p-0-30v-0-5a-programmable-supply.htmlHaving said that if it's just going to power a printer maybe something else can do the job for less; but if it's going to serve as an entry level linear power supply for your bench/lab, then the Korad KA3005D/P would be a very good choice, imo

author: wizard69
author_rank: Super Contributor
timestamp: March 03, 2021, 01:41:23 am
content: I'm going to make a few suggestions that probably fly against the grain here. So here are some points:There is huge value in building a power supply or two. It is one of the better ways to learn some basic electronics and building skills. This can be a simple as a three terminal regulator hooked to a plug pack to a far more complex unit. I'd avoid the complex at first.I actually consider buying a fancy bench power supply to start a lab with as a bad investment. You would be far better off buying a DMM or two and maybe even a scope if you can afford it. You will eventually want a good bench supply but after a bit of experience you will know what specs you need. Every ones needs are different.Batteries work. Some of my first adventures with electronics relied upon batteries. They are good enough to get you started for many projects and skills development labs.Power supplies are like DMM's eventually you will need another. Some times it makes sense to buy purpose specific supplies. For example if you are running 12VDC based electronics (automobile), a battery eliminator or or fixed 12 VDC supply may be smart.Likewise if you are doing a lot of stuff with industrial I/O it makes a lot of sense to buy a 24 VDC industrial supply and stick it in a housing. Most of those industrial supplies are rugged and specifically designed for that use case.If you are going to do a lot of work with motors it is probably a good idea to run them on DC supplies designed for motors. One issue is that motors are also generators and can easily cause issues with current and over voltage protection on a lab supply. Often these supplies are not much more than a transformer rectifier and a few caps. You can also get strange interaction between how a stepper drive operates and how some switching supplies operate. Plus a transformer and rectifier are cheap. If you do buy a switching supply for stepper usage make sure it is suitable for motor control.Now don't take all of this to mean that you don't need a good variable voltage , multi output bench power supply. You will want one but my point is don't rush into it. Take the time to understand your interest, learn a bit about the various power supply solutions (build a couple) and develop an understanding of where that bench supply might not make sense.Power supplies are often over looked when people start learning electronics. That is really sad because a good power supply is critical to keeping a digital circuit running. Frankly if you are going to build anything permanent, it will need a power supply anyways, so it is better to get a handle on supplies early.

author: David Hess
author_rank: Super Contributor
timestamp: March 04, 2021, 10:10:04 pm
content: Quote from: Zynch on March 02, 2021, 12:11:04 pmI suggest getting a separate high current fixed voltage power supply for that sort of thing. I prefer an industrial open or closed frame power supply mounted to a board rather than a consumer grade power "brick".