Show your favorite and most used benchtop PSU

[Calambres]

I've got mostly two PS:

The first is one I made when I was merely a kid. 24V and 8A. Short circuit proof and 2 x 2N3055 output stage. The initial case was much uglier than this and about 20 years ago I put it into this case and added a 220V fan. It has served me well for more than 40 years and only recently I had to change the *B-I-G* filter capacitor due to aging. Very low ripple.


The second one is my (now) most used PS. A chinese cheapie that turned out to be quite good. 0-32V and 5A. Also very low ripple. I hacked it a bit  

Now I'm making another one just for fun. This one is a dual PSserial/parallel based on two of these ubiquitous cheap chinese kits.

[emax]

Is it all the same with us EE's?

I'm not really an EE. More a wannabe. Sadly, it's  now too late for the university  ...

So I made this one from scratch:

This is WAY better than mine. 

a local electronics shop at Darmstadt

Muhaha! Zimmermann? EBG ? Man, I'm from 64401 ! 

Where are you from? Send me a PM if you want! 


(funny to find local neighbours in an australian forum)

[MDM3D]

This is the bench powersupply I just made over the holiday and is now my favorite.  It uses 3 DPS5020s. The DPS5020s are feed 50V through 4 DPS 500 CB A  dell server supplies in series that can provide 45A for a total output of just over 2kw. The only bummer I have is that I only have the ability to supply 45V max out of the 5020's because they need to have at least 55V on the input. I built this mainly for electroplating and hard coat anodizing applications where lots of power is required and ripple requirements are low. As other have stated this uses low side current measurement and all of the precautions that apply with that.
I may in the future wind a transformer for 3KW with 3 1 KW outputs so that I could isolate and series the outputs. I have no ideas as to how I could go about paralleling due to the low side current measurement but would definitely appreciate 60A as hard coat anodizing requires 40 amps per surface foot.  It is really easy to get to a surface foot on relatively small parts like heat sinks.

I have the 1st "rail" in "filtered" with a 20000uF cap had laying around and quickly removed the small multi layered ceramic capacitors that blew up on Dave's testing video.
I ordered the communications versions and have plans to put an esp in to allow remote monitoring and simultaneous settings changes.

I also need to really run a 220V outlet to the bench because if I ever manage to completely load the psu then it will probably blow the 20A breaker it is attached to. 

The attached pictures were taken during the first time I turned it on before I moved it to the bench as it has a substantial amount of gravity to it.

Some quick testing with a dmm showed a Voltage ripple under 2mV for the first rail and under 9mV for the others when lightly loaded.

[JustSquareEnough]

I've got mostly two PS:

The first is one I made when I was merely a kid. 24V and 8A. Short circuit proof and 2 x 2N3055 output stage. T

any details and pictures of the inside?

[Calambres]

The schematic is long lost (from an electronics magazine) and the PCB is the first I ever did so it's not pretty 

One of these days I'm gonna open it up and try to trace the schem. I'll take some photos and post them here.

[jayjr1105]

My one and only, homebrew.  12V5A switching supply with LTC3780 doing all the magic.

[GeorgeOfTheJungle]

Up to 350W, pure chinesium inside, works wonderfully:

[mrjoda]

I build this maybe 6 years ago and it is my No.1 from then. Keithley 2302 and Phillips 2811 are nice, but they are collecting dust on my desk most of the time. Outputs: 25V/1,5A regulated and +/-3V3; +/-5V; +/-12V unregulated/switchable. Linear, robust, low noise and fast enough...

[nardev]

[ Specified attachment is not available ] [ Specified attachment is not available ]Not the best in the wold but exactly what i needed : ) small and stable enough. RIDEN RD6006.

Good thing to mention, they were very prompt in email support. I couldn't figure out few things at first.

p.s. i did some customization, didn't like the switch and i only needed this small PSU

[SteveyG]

(Attachment Link) (Attachment Link) Not the best in the wold but exactly what i needed : ) small and stable enough. RIDEN RD6006.

Good thing to mention, they were very prompt in email support. I couldn't figure out few things at first.

p.s. i did some customization, didn't like the switch and i only needed this small PSU

Where's your mains earth??

[nardev]

Well, the socket and the cable don't have it anyway. This one was good enough for what i use this for Buuut.. i might add another cut on the enclosure and add in parallel another bigger socket with a fuse. Good idea

[unknownparticle]

I have MANY PSU's, acquired over many years.  Not my favourite, but most recent, PSU is a TTi EX4210R. This was donated to me by a friend who works for a big Tech company here in the UK. Status was unknown but I soon found a blown mains input fuse. Being in an impatient mood at the time I replaced it with one of a lower rating and applied power. Fuse was vaporised immediately!  So, I checked the input resistance and it seemed ok, certainly not suspiciously low. Next I DL'd the manual from the manufacturers site and had a look at the circuit. It's a switch mode type unit. I started to measure through the components from mains in onwards and it was then I noticed the top blown off the inrush thermistor, but, it measured ok! Then I noticed the board layout didn't correspond to the manual.  Some components in the manual weren't on the board! Long story short, although the unit was clearly marked as 240 VAC on the back panel, it had been fitted with a 115 VAC board!!!  No wonder the fuse and the thermistor had complained!  However, after fitting a new fuse and supplying the unit from my variac it worked almost perfectly!  The only fault it has is no fan supply, which is a dedicated supply from a discreet component arrangement in the auxillary supply section.  So, I need to locate that fault, which I think is a blown Mosfet. The only other parts needed are the thermistor and main filter caps, one of which is bulged at the top. So, despite the issue, this is a bit of a gift as they retail for about £400!! The reason for the 115 VAC board will be a mystery forever though!  I'll post up some further PSU tales in the future! 

[odium]

home made 30V/5A linear : 3x TIP35 output stage

multimeter is GWInstek GDM-8251A

cheers

[Mr Evil]

I only have room for one power supply on my bench. It consists of a couple of those cheap switching regulators that have the nice multicoloured displays, and a couple of slightly dubious off-line switching power supplies, which I fitted into a nice enclosure, giving 2 x 50V@5A.

The dubious power supplies generate a substantial amount of common-mode noise, as well as radiated noise, so I had to fit common-mode filters at the outputs, and cover them with aluminium plates. In the first photo you can see that one channel has had the filter and part of the shielding fitted.

[BravoV]

Congratz on your 1st post, and welcome to the forum. 

[MarkF]

I have been hooked on these little supplies since my college days.
Currently, I have three of them and a fourth 60V model.

[Mr Evil]

Congratz on your 1st post, and welcome to the forum. 

Thanks. I don't know why I didn't join this place years ago.

[artag]

I have a few of these Lambda supplies in various ranges. They're quite small, at least in panel space : 4 will fit in a 19" rack frame. Amazingly, the first two I bought were from a normal car boot sale (not an amateur radio one .. just the usual clothes and attic junk, and these lovely power supplies).

I wish I could get some more coaxial knobs to fit them, though - most have that cover over the output voltage control (right hand supply) instead. Preferably to match the current limit control, I'm fussy like that.

A tip if you have one of these to repair and need to replace the Lambda-marked 'special' regulator IC. It's a Motorola MC1566L.

Although I also have some HP and Farnell supplies with higher ratings or better precision, I use this one more than anything : it deals with the majority of needs and, most important of all, it has no fan.

I do have a couple of home-made ones as well (built while I was at high school). They still work but don't have meters though so are less convenient to use.

[Wolfgang]

Hi,

my first (1978) was a homebrew linear PSU 2-30V, 1.5A using a standard LM723 circuit with current limiter and analog meter. Big heatsink, no fan, selfmade PCB.

Now, my default PSU is the Rigol DP832A (2x30V/3A, 1x5V5A). Same as Dave.

For super sensitive stuff (ULN crystal oscillators) I use Keysight SMUs (B2962A).

High voltage PSUs I made from scratch (e.g., 250V/150mA, 500V/30mA, ...)
https://electronicprojectsforfun.wordpress.com/power-supplies/high-voltage-lab-power-supplies/

For my other projects, I normally prefer homemade standard PSUs using either LM723 or TL431 regulators.
I dont like the LM78XX and LM317 series parts too much because of more noise and many counterfeit parts.

[jogri]

My most used PSUs are those two linear Oltronix B703DT. A joy to work with, but a PITA to disassemble since there is virtually no space left unused on the inside (Marco Reps did a video on his unit if you want pictures of the inside, i am not going to open mine [btw, you can tear them down rather easily, but he somehow didn't figure out how]). The PSU on the top is still waiting for its upgrade to safety banana plugs, i am kind of hesitant to open it again.

They are relatively compact (roughly 20x20x20 cm) and feature three galvanically isolated channels each, so you can stack the outputs together to get a 100V 0.6A supply.

[kallek]

Those Oltronix power supplies look really nice.

I just built dual rail power supply, but still my favourite and most used supply is very basic LM317 voltage supply with ten turn pot.

For AC I built variable isolation transformer with meters. When there was still some space left, I installed also dim bulb tester with bypass swith to same enclosure.

[BravoV]

kallek, really nice, especially the AC adjustable PSU. 

I have isolation transformer and a variac gathering dust, I guess this will be my next project. 

Btw, that dim bulb tester with by pass switch is on the output's side right ?

Also regarding the wirings, from the AC mains, is it connected to the transformer and then the variac for the out put, or the other way around variac 1st, and then transformer for the out put ?

[kallek]

Thank you BravoV! I think it was cool project. I have used mine for testing new builds and also for 120V devices. And hopefully in future for powering restored vintage devices. 

Dim bulbs are at first from mains. If you look carefully you can see bulbs glowing from transformers idle power.

Variac is before transformer, because it is rated for higher current than transformer.

[engrguy42]

Okay, well it's not my favorite...nor is it my most used...

And, honestly, I don't want to brag, but...

>>> INSERT TIM ALLEN/HOME IMPROVEMENT GRUNTS HERE <<<<<

As Nigel Tufnel so eloquently stated in Spinal Tap, this thing goes up to 11.

My modification to a 460 watt ATX power supply. And yeah, that's right, it's running just under 20 amps on the 12v output.

>>> MORE TIM ALLEN GRUNTS <<<<

BTW, not sure if you're all aware, but the International Institute for Determination of Ultimate Coolness (IIDUC) recently issued the following statement :

"The truly cool people use converted ATX power supplies".

So, for all of you "I hate ATX" fanboys, there you have it...

Now, to dispel a related myth:

If you run a big 'ol 4 inch diameter, 200 watt, 5 ohm rheostat at just over 200 watts for 30 seconds or so, it will NOT necessarily set off your smoke detector. Yeah, it might smoke a lot, but if you have a portable fan standing near your workbench and run over and turn it on quick enough, no problem.

[jaycee]

Not the first PSU I've built, but the first one that was more than an LM317, and built into a proper box

It's a fairly common topology.. A TL082 as sense amps, and another as error amps. Voltage reference is a TL431. Transformer is custom wound but an off the shelf 2x9V (plus another small 2x9V for the opamp supplies) would work. The metering is done using an Atmel ATMega324, which also controls switching the load on and off via an illuminated pushbutton

I made a few little mistakes, the metering is not very accurate at the low range because the ADC in the ATMega is not very accurate near ground. I should have added some bias to the sense amps so that the voltages they output doesn't go near ground - this doesnt bother the opamps because they have a -ve rail

edit: Oh yeah, the important bits. It's 0-18V at 0-1A, and 90% of the components are recycled parts - including the ATMega324!