The LM338 Variable DC - DC Power Supply DIY Kit - AC or DC Input

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Category:

Science & Technology

Tags:

• lm338
• lm338k
• power
• supply
• circuit
• project

[robrice2004]

What about a dc to ac converter do you have a kit for that

[patrickikis]

@robrice2004 No, but if you have a 12v battery, you can use an inverter to convert it to 120VAC.

[robrice2004]

@patrickikis Yeah I know, I just thought it would be nice to be able to make an inverter maybe even a pure sine wave inverter...or a grids tie inverter...I not talking about something that cost less Im talking about something to make it understandable how it works and to better trouble shoot

[patrickikis]

@robrice2004 Ah, good call! Sorry about the misunderstanding. I'll think about it. Right now, I'm working on a voice recognition kit, a stand-alone RFID kit, and a voice changer kit, but I'll make a note of it.

[Riskteven]

So if this is set to 5 volts, charging a super capacitor safelyis possible, even without a voltmeter?

[jonathans1212]

hey @patrickikis i was thinking about converting a laptop power supply into a multi power supply

the power supply is 19v and 3.5amp out i wanted to make it into a 5v(low noise) for sensitive circuits a 7.5v (thinking lm317) to power an arduino and a 12v 1-2amp out to drove relays and another lm317or lm350 for a variable out for all my arduino projects

what regulator should i use for 12v more than 1amp out not a 7812???

[robrice2004]

@patrickikis Cool, thanks I think this is something that interests a lot of renewable energy people and at first may not be cost effective but in time may pay off...

[patrickikis]

@Kankki1 Yes, there are 0.1uf (100nf) caps before and after the LM338 =)

[Kankki1]

@patrickikis The one after the regulator should be around 100nF, according to the datasheet. Oh well, better transient response with a larger cap.

[patrickikis]

@Slovenija12345

The capacitors are more than 2cm away from the LM338, which is properly heat sinked, with a fan. The capacitors will not be exposed to much heat at all, even when the LM338 is heavily loaded. I took this into consideration in the design process.