Variable Voltage box mod with lm317

[Jim211]

Has anyone built a variable voltage box mod using a lm317? I have the circuit breadboarded and it works great but the ic gets a little hot and was wondering what size heat sink to use that would fit in a aa battery size slot along with rest of circuits?

Thanks in advance for any advice.

 

[Java_Az]

Those are cutting it close if not a bit under what you want it to handle in amps. They are rated @ 1.5 amps. I have a variable card with a amp readout at 5 volts i usually pull around 1.65 to 1.85 amps with a regular atomizer and well over 2 amps with a LR atomizer. Personally i would look for something rated a bit higher i don't think it will last long at high voltages even with a large heat sink.

 

[ChuckB]

I made a version of the Puck with one. It works ok but it does get hot. I don't expect it to last forever, but I already had the part in my junk box so didn't have to go buy one.

 

[Jim211]

I know its cutting it close, but i have over 50 lm317's and not much cash. planning to socket it and use best heatsink i can find for the space ( about 1/2 aa battery hole). From what I have seen with all my cartos/atomizers 4volts was the max i was drawing b4 i got burnt taste. Also breadboarded 317 has no heat sink and hasn't blown yet and used over 10ml juice with it. But it does get really hot.