Guide to the use of Resistors(II)

Bias

    To work more efficiently, transistors or tubes need to be biased correctly. That is to say, to control the electrode-base, gate or gate-there must be a specific voltage or current. The resistor network is used to accomplish this. Different circuits require different bias levels. The bias of a RF transmitter amplifier is usually different from that of an oscillator or a low level receiving amplifier.

Current limiting.

A resistor can interfere with the flow of electrons in a circuit. Sometimes this is to protect a particular element or circuit. A receiving amplifier is a good example. Resistors can prevent transistors from producing because they consume a lot of power, Heat. If there is no resistor to limit or control the current, the transistor will be burned out by a direct current independent of the signal. An amplifier that is not properly designed needs to replace the transistor frequently, not because no resistor is used in needed place, but the resistance of the selected resistor is incorrect.