This is very cheap (50-60eur in components) and very powerful power supply for laboratory/workshop use. It's made from 3 printed pieces from PLA/ABS or any other material, except flex.

It will output adjustable 0-45.00V and 0-5.000A in very fine increments. It's a little electrically noisy (maybe not perfect for supplying power for precision electronics) but will do the job for most of workshop use. It's very precise in setting the voltage and current! It's absolutely quiet (no fan required).

You will also need:

• 250W 48V AC-DC transformer/power supply (ebay, aliexpress)
• Adjustable voltage/current buck (50V 5A) (banggood, ebay)
• some 3 core mains cables (local shop or from home junk)
• 4x (2 red + 2 black) 4mm female plugs (local shop or any electronics store, ebay...)
• 1x standard 10 or 16A 250V switch (local shop or any electronics store, ebay...)
• 5mm red LED (optional) (maybe you got it at home!)
• 10k normal resistor (optional - for led) (maybe you got it at home!)

Links for power supply and buck:
http://www.ebay.de/itm/222240258495?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://www.banggood.com/DP50V5A-Buck-Adjustable-DC-Power-Supply-Module-With-Integrated-Voltmeter-Ammeter-Color-Display-p-1050061.html?rmmds=myorder

Printer setting: I've printed in white PLA and than spray painted with acrylic paint in matt black.

Please bear in mind that device will work on 220V and it's not cool to mess around with it. Be careful - I don't take any responsibility if you're making or misusing this. Better to leave a comment if you're not sure what to do than fry something.

Best regards,
Jure Korber