Decoding Electrical Circuit Codes(Terminology 2)

Resistor:

Restrict the flow of electric current, and are rated in ohms and have a color code on them to indicate their value, tolerance, and sometimes quality

Variable Resistor:

Also restrict the flow of current

Rheostat:

A type of variable resistor with two contacts, usually used to control current

What are examples of controlling current?

Adjusting lamp brightness or motor speed

Potentiometer:

A type of variable resistor with three contacts that is used to control voltage

Preset variable resistor:

A device that operates with a small screwdriver or similar tool

When is a preset variable resistor designed to be set?

When the circuit is made and then left without further adjustment

Capacitors:

Store electric charge

Why are capacitors used with resistors in timing circuits?

Because it takes time for a capacitor to fill with charge

Why are capacitors also used in filter circuits?

Because they easily pass AC(changing voltage) signals but block DC(constant voltage) signals

Diodes allow:

Electricity flow in one direction

In a Diode, The arrow of the circuit shows:

The direction in which current can flow

What is the electrical version of a valve?

Diodes

What are valves?

Early Diodes

Light Emitting Diodes(LEDS) emit light when:

electric current passes through them

Specialized Diodes, Zener Diodes:

Allow current in the opposite direction after a threshold is met

Transistor:

Amplify current, they can be used to amplify the small output current from a logic chip so it can operate a lamp, relay, or other high current device

Amplifier:

Isn’t actually an electronic component but instead a complex circuit

The block diagram symbol shows:

Where an amplified circuit would be connected

Amplifier circuits are used:

To magnify power, current, or voltage

Antenna:

A device designed to receive and/or transmit radio signals