Transistor recomendation...

[cocoadev]

Hi, I'm trying to make a luxeon LED 'pulse' to music. Could anyone recomend me a transistor...

**broken link removed**

 

[jrz126]

what kind of current are you looking for in your LED? and what is your forward voltage?

I'd suggest using an LM3915 IC which is specifically designed to light LED's in response to music.

You can connect a transistor to the outputs of the LM3915 so that you can supply a sufficient amount of current to the led.

 

[cocoadev]

what kind of current are you looking for in your LED? and what is your forward voltage?

700ma @ 3.9v

I'd suggest using an LM3915 IC which is specifically designed to light LED's in response to music.

Bit overkill for my needs i rekon.

Thanks.

 

[Russlk]

You could use a TIP32 PNP but your audio would have to be at +12 volts. A better circuit is below, using an NPN transistor:

 

[cocoadev]

thanks Russlk, I cant work out the value of R2 there? what would it be?

 

[Nigel Goodwin]

thanks Russlk, I cant work out the value of R2 there? what would it be?

It's labelled 1MOhm - bad choice of graphic format though, using the JPG format loses quality and makes the file considerably larger. For diagrams you should use GIF, 100% quality, and smaller files - save JPG's for photo's where it's compression works, and the losses don't matter.