View Full Version : switching tip 29

01-17-2006, 02:56 AM
·i would like to switch a cold cathode inverter with my basic stamp. the inverters run on 12 volts dc and about 600 ma. i got some tip 29a transistors from a friend and after looking at the data sheet·i figured they would work just like a 2n2222. but they dont seem to be switching. when i turn power on they just let the juice through and the cold cathodes light up. i know i probably need some fly backs diodes or something too.
thanks for your help...

01-17-2006, 03:01 AM
Try a TIP120.· They are· Darlington transistors, and will handle 5 amps.

Sid Weaver
Do you have a Stamp Tester yet?


Chris Savage
01-17-2006, 03:25 AM
To answer your question on the TIP29a would require the datasheet, but you may need more current, hence a different resistor on the base to drive this transistor.

Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)