Benchtop Power Supply

[TorqueRanger]

Well I am finally getting tired of making lets say some of craziest home power supplies ... I want to make a homemade power supply but I need it to fit in a box just like the µSupply  but plugs into the wall ...The reason is that my work space is my kitchen table and I really don't have a place to store this stuff but a 3 drawer tote .. I have search a around but schematics just plains scare me in the terms of safety and over all quality... I would love to build something like the µSupply but I can't write code from my life and in the end wind up just killing it.. Do you guys know any plans out that will fit in my specs???


Spec
 Through-hole design
Safe
Fit into a small box
0-15 or 20v
3A














Thanks
JAy

[IanB]

It may help to direct the replies if we can clarify one or two questions that come to my mind, at least.

Firstly, do you "want to make" or "need to own"? That gets the make or buy question out of the way.

Next, is "small and compact" really important to you? (Sounds like it is.)

Lastly, what about budget? How much are you willing to spend?

If you want small and compact, then a linear supply is likely not going to suit. It will be big and heavy. That would leave you looking at a switch mode supply--not perfect for everything, but good for many things.

Variable voltage switch mode supplies are hard to design and build. Most design guides ask you to pick your output voltage and work backwards. If your output voltage isn't fixed, you get into uncharted territory.

Have you considered one of the variable voltage regulated DC power adapters available as a wall wart? One of those could be really handy in your circumstances.

A more complicated possibility is to use a laptop power brick as the main supply to a linear variable regulator in a separate project box. Most laptop power bricks supply 19 V at 5 A or more. They make ideal isolated supplies in a nice form factor.

[TorqueRanger]

Firstly, do you "want to make" or "need to own"? That gets the make or buy question out of the way.

Well this would be my first real project that I would like to build but buy is ok too

Next, is "small and compact" really important to you? (Sounds like it is.)

Size does matter but the size can change but I don't want to be lugging around this big power supply

Lastly, what about budget? How much are you willing to spend?

What would one of these cost???

If you want small and compact, then a linear supply is likely not going to suit. It will be big and heavy. That would leave you looking at a switch mode supply--not perfect for everything, but good for many things.

Variable voltage switch mode supplies are hard to design and build. Most design guides ask you to pick your output voltage and work backwards. If your output voltage isn't fixed, you get into uncharted territory.

Have you considered one of the variable voltage regulated DC power adapters available as a wall wart? One of those could be really handy in your circumstances.

I have been doing this for years but it's becoming to much of a pain to use ..

A more complicated possibility is to use a laptop power brick as the main supply to a linear variable regulator in a separate project box. Most laptop power bricks supply 19 V at 5 A or more. They make ideal isolated supplies in a nice form factor.

I know I have a laptop power supply floating around here some where...
Would this cut down on the size
Where would I get plans for the rest?

[T4P]

The issue with getting 19V down to let's say at 12V @ 3A can be quite a task to dissipate in a "compact" form factor when using linear
But i got a good one for ya
http://www.ebay.com/itm/ZXY6005-DC-DC-power-module-60V-DC-CCCV-stabilized-voltage-supply-High-Voltage-/180819803054
http://dx.com/p/zxy6005-2-6-dc-dc-60v-constant-voltage-current-regulated-power-supply-module-green-151115
Also remember, this is a step-down which means you can get less than about 18V from a 19V laptop power pack

[TorqueRanger]

Anyone one every built one of these and has pics
http://tuxgraphics.org/electronics/201005/bench-power-supply-v3.shtml

[SH@RK]

Anyone one every built one of these and has pics
http://tuxgraphics.org/electronics/201005/bench-power-supply-v3.shtml

Dave has shown tow of them in one video (pictures in the attachments )

EEVblog #168 - How To Set Up An Electronics Lab (go to 5:02)



If any one can bring the way of building them because I searched bu found nothing ?

[Monkeh]

Anyone one every built one of these and has pics
http://tuxgraphics.org/electronics/201005/bench-power-supply-v3.shtml

Dave has shown tow of them in one video (pictures in the attachments )

EEVblog #168 - How To Set Up An Electronics Lab (go to 5:02)



If any one can bring the way of building them because I searched bu found nothing ?

Those are quite obviously not the Tuxgraphics PSU...

[rolycat]

Anyone one every built one of these and has pics
http://tuxgraphics.org/electronics/201005/bench-power-supply-v3.shtml

This PSU design is famous on the EEVBlog forum - search for 'tuxgraphics' for earlier critiques.

It's an example of the inappropriate application of a software solution to a hardware problem and I'm sure the engineers here will be happy to explain (again) why this is a bad idea.

The supplies Dave mentions in his blog are not the same thing at all.

[SH@RK]

Those are quite obviously not the Tuxgraphics PSU...

The supplies Dave mentions in his blog are not the same thing at all.

Sorry , I misunderstand .

I thought they were same idea .

[TorqueRanger]

Anyone one every built one of these and has pics
http://tuxgraphics.org/electronics/201005/bench-power-supply-v3.shtml

Dave has shown tow of them in one video (pictures in the attachments )

EEVblog #168 - How To Set Up An Electronics Lab (go to 5:02)



If any one can bring the way of building them because I searched bu found nothing ?

I don't know if I am slow or something but I can't seem to find these kits that where metioned in the video ?





Oh by the way whatever happened to Dave's USpupply that was suppose to come out and has anyone seen the final product functioning?

[TorqueRanger]

The issue with getting 19V down to let's say at 12V @ 3A can be quite a task to dissipate in a "compact" form factor when using linear
But i got a good one for ya
http://www.ebay.com/itm/ZXY6005-DC-DC-power-module-60V-DC-CCCV-stabilized-voltage-supply-High-Voltage-/180819803054
http://dx.com/p/zxy6005-2-6-dc-dc-60v-constant-voltage-current-regulated-power-supply-module-green-151115
Also remember, this is a step-down which means you can get less than about 18V from a 19V laptop power pack

How hard would to be to get a schematic for that circuit because I would have to figure how to mount that some kind of box???
My idea was to move the leds,screen display,and buttons to the front panel but how would I control the voltage and current from those tiny pots with being  a pain to do ??

[firewalker]

Anyone one every built one of these and has pics
http://tuxgraphics.org/electronics/201005/bench-power-supply-v3.shtml

I did. Years ago. It was the plain R-2R version. I think a user here had build the new version (R-2R+PWM).

It's a nice design to demonstrate what an mcu can do (it combines I/O, DACs, ADCs, general transistor calculations e.t.c. A really nice exercise for beginners, with clean understandable code in C), but not suitable for a lab or any serious work.

Edit:

I thought I had dismantle it, but no. It was sitting in a box. It still works.


Alexander.

[TorqueRanger]

Well I got to the point to where size doesn't matter ... So does anyone know who makes a kit or really good schematic for a bench top power supply?

[IanB]

Well I got to the point to where size doesn't matter ... So does anyone know who makes a kit or really good schematic for a bench top power supply?

This subject has been discussed to exhaustion around here, and the answer is always that you can buy one far cheaper than you can make one. A power supply is a tool, and for most people you buy the tools you need so you can concentrate on the interesting things you can make with those tools. Making a laboratory power supply is a bit like making a hammer or making a saw. OK, you can do it, but for most purposes what is the point?

[Isamun]

Anyone one every built one of these and has pics
http://tuxgraphics.org/electronics/201005/bench-power-supply-v3.shtml

I buildt one of these as my first kit a few months back. Only issue i ran into was getting the code to compile; I had to change some of the keywords..
I can send you my code if you want to give it a try.

Another downside is the price. The kit + Atmega8A + LCD + programmer = approx 100$. And on top of that you need a DC source.

I used a beefy 7A 19.5V laptop brick (edit)  wich gave me 18.2V max output.

[TorqueRanger]

Whats your thoughts on this Power supply
http://jumperone.com/2011/08/lm317-adjustable-psu/


My main concern with this design is ,
No short circuit indicator
No short circuit protection
I am not sure about anything else so I asking you guys and how hard would it be to add this features to this design ??

[mariush]

It's like the title says, a basic linear "power supply".

The author never intended to be more than that.

If you want something better, you go with better regulators that have built in short circuit protection like LM2941 , or even regulators that have a flag pin which goes high on low input voltage, output current limit, over temperature shutdown etc like MIC29303 (picture doesn't match on digikey) / MIC29503

That LM317 is a "jellybean" chip, good but old, requiring a few volts about the output voltage just to regulate properly, there are better solutions for doing a simple linear psu.

[diogoc]

If anyone is interested here is almost the schematic of the chinese ZXY6005S power supply.
https://drive.google.com/file/d/0BzkDuDi_KxbsVGRiZ0lfYjkxaHM/edit?usp=sharing

[hansaya]

Hey guys

I made a bench top power supply using these modules, Pictures :http://imgur.com/a/H5vB1

Only difference is I ended up changing main buck regulator from XL7005E to XL7005A. XL7005A (http://www.xlsemi.com/datasheet/XL7005A%20datasheet-English.pdf) can handle the voltage up to 80v so it wont blow up if you go over 65v(if you wanted use the unit up to 62v). Other thing is its an good idea to change all the capacitors to a good brand and maybe higher rated caps.

I wanted to Thank you diogoc for sharing the schematic, it was pretty useful when I accidentally burned few things on the board .

[csmithdoteu]

A couple of options...

Firstly, you could just buy a cheap bench supply. Any generic HY1803D fits the bill for such things and you couldn't build one for twice the price.

Secondly, I suffer from the same problems as yourself with respect to working area. Mine is the dining table instead. I tend to not need anything greater than 12v so I settled on using a 12v 7Ah sealed lead acid deep cycle battery as a power supply. This is trickle charged with a wall wart. Cheap, reliable, nice clean DC out.

If I need anything less, I'll integrate a linear regulator into the design or use a simple ugly LM317 board I have. I make no apologies for this one - it's ugly but it works reliably and has done for a long time. Has 4mm panel sockets soldered to the board for test leads:



Safety note: SLA batteries can deliver a lot of current. Mine is fused at 3A quick blow and I tend to use a 10-100 ohm resistor as a fuse inline with the circuit being developed as well as that will toast instead of the target if anything goes wrong.

[ECEdesign]

Take a look on eBay for some of the older HP E series power supplies.  They are really great supplies and you can snag them for pretty cheap.

[LabSpokane]

Take a look on eBay for some of the older HP E series power supplies.  They are really great supplies and you can snag them for pretty cheap.

I just bought two E3610As for $50 each off eBay. They are in near perfect condition. That's a rare deal, but it is possible to snag a good power supply cheap.

[10101]

If you still want a diy design, idk if these two are good (they look awesome though  ) but i'm going to let more experienced people comment on that 

1-2 amps versions:

https://www.eevblog.com/forum/projects/diy-bench-power-supply-psl-24012/

4 amps version:

https://www.eevblog.com/forum/projects/diy-bench-power-supply-psl-3604/

[Blisk]

Can anyone help me calculating how to get 12V out of XL7005A input voltage is 60V.
I have calculated 30Kohm and 3Kohm resistors but I get 2V output!

[mvs]

Can anyone help me calculating how to get 12V out of XL7005A input voltage is 60V.
I have calculated 30Kohm and 3Kohm resistors but I get 2V output!

With 3K and 30K you should have either 1.25*(1+3/30)=1.375V or 1.25*(1+30/3)=13.75V, depending on the positions of your resistors.
For 12V, you may choose 3.9K and 33K  1.25*(1+33/3.9)=11.82V