Introduction: Use an NPN Transistor As a Switch! (No Soldering!)
Make an LED switch on or off depending on the state of an NPN transistor.You will need:
7 Solid - Core Wires
1 NPN Transistor
2 AA Batteries
1 Green LED
1 LED (Any color!I used a white one that glows an amber color.)
That is all!Now let us get started!
Step 1: Step 1
These wires are were you wil connect the battery! (The left wire is positive,the right wire is negitive.)
Step 2: Step 2
Then add this blue wire wich will connect to the NPN transistor's collector.
Step 3: Step 3
Then connect the yellow wire from the base of the NPN transistor to positive.Also,you can see the blue wire and where it connects from the last step.Then,connect one lead of the LED of any color to the NPN transistor's emitter.After that,connect the dark blue wire to the LED's other lead and connect that to negative.
Step 4: Step 4
Last but not least, add a green LED to tell you if your machine is on.Connect one lead to positive with the dark blue wire and the other to negative with the orange wire.
Step 5: Lastly
Here is a pic. and a video of the final product:
Oh,and just to note that as long as the yellow wire is connected to positive the LED of any color will stay on.
If you take it out, the NPN transistor will become switched off and the LED will turn off.Also,there is an on and off circuit schematic!