How to Use a Transistor to Amplify Power

Transistors have replaced vacuum tubes as the active component of choice in amplifier circuits. Transistors waste less energy to heat dissipation and are less expensive to manufacture than vacuum tubes. Using a transistor, you can create a simple, yet effective signal amplifier called a Class A amplifier. A Class A amplifier is commonly used in audio preamp and amplifier circuits and is well known for its high-fidelity output signal characteristics.

• 1

  Cut three equal-length pieces of electrical wire. Strip off one-half inch of insulation from each wire end.

• 2

  Crimp one of the ring terminals to the negative lead on the capacitor. Crimp the other ring terminal to one of the ends of the first wire.

• 3

  Twist together the positive capacitor lead together with the base lead on the transistor. Solder the connection.

• 4

  Twist together the loose end of the first wire with one of the leads from the 200 Kiloohm resistor. Solder this twisted wire pair to the emitter lead on the transistor.

• 5

  Twist together one of the leads from the 3 Kiloohm resistor with the emitter lead on the transistor. Solder this connection.

• 6

  Twist together one end of the second wire to the unoccupied lead on the 200 Kiloohm resistor. Solder this connection.

• 7

  Twist together one end of the third wire with the unoccupied lead on the 3 Kiloohm resistor. Solder this connection.

• 8

  Attach the unoccupied end of the second wire to the positive terminal on the power supply. Attach the unoccupied end of the third wire to the negative terminal on the power supply. The ring terminal connected to the first wire is the amplifier output terminal; the ring terminal connected to the capacitor is the amplifier input terminal.