BC108 Transistor

The BC108 Collector is connected to the positive (+ve) supply via the load. NB: If the load is inductive i.e. has coil windings such as a relay, solenoid or motor, then it is usual to connect a diode across it to prevent the Back EMF from damaging the transistor. (Cathode to supply).

The input is connected to the Base via a limiting resistor (typically 1K). The Emitter is connected to the negative (-ve) supply (0V).

Uses: As current amplifiers and electronic switches, for example LED Drive Amplifiers, Relay Drive Amplifiers, Audio Amplifiers.

Data: Voltage between Collector and Emitter 3 - 20Volts max.

• Power handling capacity 100 mWatts max.
• bCurrent handling capacity 300 mAmps max.
• Amplification (gain) greater than 125.