Build Your Own Arcade Controls Forum

Main => Everything Else => Topic started by: SirPeale on December 24, 2007, 08:00:17 am

Title: Joule Thief
Post by: SirPeale on December 24, 2007, 08:00:17 am
I've been wanting to replace the green LED on my computer case with a blue one I scavenged from an LED pen that the batteries died in.  Direct replacement won't work because the LED is expecting at least 3 volts, but the computer only puts out two.

Saw a great project on Make a couple days ago - the Joule Thief (http://blog.makezine.com/archive/2007/12/smt_joule_thief.html).

edit: that's the SMT version... here is the regular version  (http://blog.makezine.com/archive/2005/11/how_to_make_a_joule_thief.html?CMP=OTC-0D6B48984890).

Figured I might be able to scavenge parts off some TV chassis and motherboards I've got lying around. 

I took a C3199 thinking I could use it (it's a NPN transistor) but in all the schematics I've read it calls for parts that cross to an NTE123.  It didn't work, and I can't find a part to scavenge.

I don't know enough about electronics to know *why* it doesn't work, can anyone explain?
Title: Re: Joule Thief
Post by: Ed_McCarron on December 24, 2007, 09:09:56 am
Is C1399 a house marking?  It didn't pop up in many searches.

My guess?  The gain on the part might be wrong.  Oscillators can be kinda finicky.
Title: Re: Joule Thief
Post by: SirPeale on December 24, 2007, 11:37:25 am
Typo - C3199.