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What do I need to make a constant current driver for a 5w LED? Answered

I have a Vollong 5w 350 lumen LED. I was told i have to use a constant current driver for it to work. I looked at some instructions on here of how to build your own, but it was for a 1w and he had 200mA of current. I am needing somewhere around 700mA and a voltage of 7v. Can anyone explain what parts i need to substitute to get this made? I'd like to just make one myself instead of waiting 3 weeks for one to come in. Any help would be appreciated. Thanks!

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lex76

3 years ago

would like to see examples also myself

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steveastrouk

6 years ago

Here's a linear circuit that will do it - but you need a heatsink on the LM317 !!!

Copy of maths.jpgtrimmable current source.JPG
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ddinhsteveastrouk

Answer 5 years ago

maybe some examples with your formual please

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MattATCsteveastrouk

Answer 6 years ago

Ok I have the lm37 but what type of resistors are those? (1w,1/2w, 1k ohms, etc.)

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steveastroukMattATC

Answer 6 years ago

The 0R5 needs to be rated to handle I2x 0R5 watts.

The others can be regular 0.125 or whatever.

Steve