Mini auto relay T78, 15.7*12.3*14mm starter relay, Fuel pump relay

Description:

Relay is an electromagnetic device which is used to isolate two circuits electrically and connect them magnetically. They are very useful devices and allow one circuit to switch another one while they are completely separate. They are often used to interface an electronic circuit (working at a low voltage) to an electrical circuit which works at very high voltage. For example, a relay can make a 5V DC battery circuit to switch a 230V AC mains circuit. Thus a small sensor circuit can drive, say, a fan or an electric bulb.

What do SPST,SPDT,DPST and DPDT mean?

SP and DP refer to single pole and double pole, ST and DT refer to single throw and double throw.

Pole refers to the number of circuits controlled by the switch:SP switches control only one electrical circuit. DP switches control two independent circuits(and act like two identical switches that are mechanically linked). Don't confuse "pole" with "terminal". The DPST switch, for example, has four terminals, but it is a DP, not a 4P switch.

Throw refers to the extreme position of the actuator: ST switches close a circuit at only one position. The other position of the handle is OFF. DT switches close a circuit in the UP position, as well as the Down position(ON-ON). A DT switch can also have a center position(frequently ON-OFF-ON).

Single pole/throw and double pole/throw switches are by far the most common switches, but tripe and quadruple configurations are also available. They are commonly denoted 3PST,3PDT,4PDT, etc.

Applications:

Suitable for household electrical appliances, automation system, electronic equipment, instrument, meter, telecommunication facilities and remote control facilities.

General data:

Coil data (@20°C)

Outline dimension(mm):

PCB board layout and Wiring diagram: