Pages: [1]   Go Down
Author Topic: Drive a load with external power source using NPN and Arduino output pin  (Read 733 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 1
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Here is an image http://i.imgur.com/sCGoZ.png 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.
Logged

California
Offline Offline
Faraday Member
**
Karma: 82
Posts: 3123
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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

Pages: [1]   Go Up
Jump to: