Transistor Tester
If a good transistor is connected, it will produce a short across the LED pair when the voltage is in one direction and only one LED will flash. ***If the transistor is open, both LED's will flash and if the transistor is shorted, neither LED will flash.
Components REQD.:
1) 555 Timer
2) Breadboard & Wires
3) 33k Resistor [x1]
4) 220R Resistor [x4]
5) 10uF Capacitor [x1]
6) 1N4148 Diode [x2]
7) LED [x2]
8) Transistor [any type]
9) 9V Battery
10) Switch ON/OFF [optional]