Relay Terminology

SCR - A semiconductor which is made from silicon used to convert AC power to DC which can be used to control or rectify AC power semiconductors.

Diode - A semiconductor which allows electric current to flow easily in one direction but not in the other.

Rectifier - A semiconductor used to convert AC power to DC. It allows current to flow in one direction and prevents the flow of current in the opposite direction.

Discrete Device - An individual electrical component packaged or unpackaged, such as a resistor, capacitor, transistor, diode, etc.

Heat sink - A material with good heat conducting or dissipating properties to which a packaged device is attached to cool and maintain the output semiconductor junctions within the rated temperature range.

Trigger - To turn on an SCR utilizing its gate.

Thyristor - A term for the general class of semiconductor devices which includes SCR’s, triacs, alternistors, etc.

Anode - Positive terminal of an SCR or Diode. Positive with respect to cathode and or gate terminals.

Cathode - Negative terminal of an SCR or Diode with respect to the anode.