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Author Topic: Drive a load with external power source using NPN and Arduino output pin  (Read 886 times)
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Here is an image of the components. It should be very simple. I have a Nerf gun, 12v power source, NPN transistor and Arduino.

I want to fire the gun (connect to 12v battery pack) when pin 13 goes HIGH via NPN.

I have tried a few configurations but nothing works, either I get nothing or the transistor gets so hot it starts to smoke.

I have been using both 2N3904 and MPS2222A which I can get working with LED fine so I know they work.

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You need a series resistor between the base of the transistor and the Arduino pin, like this:

« Last Edit: October 08, 2012, 10:44:44 pm by Arrch » Logged

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