The Transistor is basis of modem day electronics and computing. It is used in electronics for two main application.
1. As an electronic switch – the transistor use small electronic signals to its base pin and then allows electricity to flow between its collector and emitter pins like a switch.
2. As an amplifier – the transistor receives small signals to its base pins and then allows a larger relative amount of electricity to flow between its collector and emitter pins therefore amplifying each small signal.
- If any component is getting hot disconnect the battery.
- Ensure a resistor is used in the circuit or LED will be burned out and damaged
- Ensure LED positive leg (longest) is connected to positive side of circuit
- Check battery voltage with multimeter in Volts DC mode
- Try a different LED in case it has been burned out (ensure you are using a resistor!)
- Look at breadboard picture bellow and ensure all connection are correct.
|VCC1||1||4.5V – 6V Battery Supply|
|R1||1||330 Ohm Resistor|
|R2||1||22K Ohm Resistor|
|LED1||1||Red LED 5mm|
|S1||1||6mm Push Button Switch|
|Q1||1||NPN Transistor BC546|
Fritzing Breadboard Layout and Schematic Diagram:
Note: there are multiple variations of transistor which will effect the performance of this circuit. If you are using a BC327, BC546, BC547, BC548 please use the following breadboard layout which has the collector on the left (CBE if the flat side was down when looking from above).
If you are using a 2N222 or similar which has the opposite pin configuration (EBC) you will need to flip the transistor 180 degrees. Please see this link for more details.
- Ensure LED, Diode, and battery are in correct polarity (direction)
- Read Transistor part number and follow instructions above
Finished? Now lets checkout The Capacitor