# Transistor Switch Circuit Problems

**URL:** <https://community.sparkfun.com/t/transistor-switch-circuit-problems/31739>\
**Category:** Projects\
**Created:** [October 18, 2015, 8:39pm UTC](https://community.sparkfun.com/t/transistor-switch-circuit-problems/31739 "2015-10-18T20:39:44Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Astrauk](https://avatars.discourse-cdn.com/v4/letter/a/8dc957/32.png) [@Astrauk](https://community.sparkfun.com/u/Astrauk)\
**Post date:** [October 18, 2015, 8:39pm UTC](https://community.sparkfun.com/t/transistor-switch-circuit-problems/31739/1 "2015-10-18T20:39:44Z")

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Alright I’m sure this is super simple, but I’m new to electronics and circuitry and having a very hard time getting this to work. Basically for an upcoming cosplay I’m building a lightsaber, I wanted something higher quality then the cheap ones you buy at stores, but more customizable then the ones I could buy anywhere (I’m 3d printing most of it). For the electronics, I took out the sound board from a cheap $10 plastic lightsaber I bought from the store, and I bought a high-powered led with a heatsink and everything. I could’ve simply run the soundboard and led off of separate power supplies with two switches, or figured out the resistors and stuff necessary, but I wanted to do just a little bit more with it. So basically the soundboard had an led built in that flashed when lightsaber clashed and such, I want to use that to switch the high powered led on and off so I get those effects and everything is controlled nice from the soundboard. After ordering some transistors, a breadboard, and some resistors from sparkfun, I tried building a simple transistor switch circuit, I got it all working after a fair bit of work until I plugged the led in, it was really dim and I couldn’t figure out why since the voltage was going through fine, then I did research and checked the amps, and I was going from 3.2 amps into the transistor, to 2.4 mA’s out, the led has a forward voltage of 3.15 at 1000mA, and I’m running it off of four AAA batteries. After doing more research I can only assume that’s because the transistors I bought are not rated high enough amp wise for this function. I figured it would probably be best to try and consult some experts on this to see if all I need to do is find better transistors, or if I need a different kind of switch/circuit altogether. I don’t know if you guys need any more information, but I’ll do my best to provide what I can if you do. Thanks.

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**Author:** ![Ross\_Robotics](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@Ross\_Robotics](https://community.sparkfun.com/u/Ross_Robotics)\
**Post date:** [October 21, 2015, 1:29pm UTC](https://community.sparkfun.com/t/transistor-switch-circuit-problems/31739/2 "2015-10-21T13:29:09Z")

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Would be helpful if you gave us the specs on your transistor. Or even the model… Also a schematic of how you have it hooked up.