2 replies to this topic

[philthyy]

I am currently attending college for an associates degree in electrical engineering and was hoping for some help on one of my school projects. I am building a ring counter using a standard TTL IC (I forget the number on the chip just now) and I want to use it to control some Hobbyking LED strips I am installing on my Parkzone Stryker. The problem is that the LED strips need 12 volts and my IC only puts out 5 volts. So I was thinking of using the output from the IC to control a transistor to switch the 12 volts to the LEDs. Would this work, and if so do I need to limit the voltage/current from the IC to the transistor? And what transistor should I use? Thanks!

[Mr.RC-Cam]

You shouldn't have any problems finding online details on how to use a transistor to act as a switch. For example, it is a common thing to do when interfacing high current hardware to a microcontroller. This should get you started: http://www.ermicro.com/blog/?p=423

The transistor you select should be rated for the worst case load current. A common-as-dirt 2N2222 (PN22222, 2N2222A, etc.) is a fine choice if the expected load current is under 500mA. You didn't say what current the LED strip needed, but I suspect it is not much.

[philthyy]

Thanks! That is an awesome site! My LED strip has 60 LEDs on it. It is from Hobbyking and they rate them at 400mA. I will be running two strips initially, and later adding two more strips. My ring counter has four outputs, and I would like to have a full LED strip on each output.