What is the Single Pole Double Throw (SPDT) relay? The Single Pole Double Throw SPDT relay is quite useful in certain applications because of its internal configuration. It has one common terminal and 2 contacts in 2 different configurations: one can be Normally Closed and the other one is opened or it can be Normally Open and the other one closed.. So basically you can see the SPDT relay as a.. Single Pole Double Throw Switch Backside. The SPDT switch has three terminal A, B and C. In this A is common to input terminal which is connected in the source; B is connected with circuit 1 and C is connected with circuit 2. a simple break-before-make changeover switch: A (Common) is connected either to B or to C.
Single Pole Double Throw Features. SPDT Relay; High Switching Current; Normally closed relay ; Schematic. Fig 2: A Single Pole Double Throw relay diagram. How does the Single Pole Double Throw relay work? An SPDT relay internal configuration has one control input terminal that controls two outputs. Therefore, it has five terminals: two relay.. This is the diagram below to learn all the pin terminals of a Single Pole Double Throw (SPDT) Relay: The 2 COIL terminals is where the voltage is placed in order to energize the coil. Place the relay's rated coil voltage on these terminals.