K4-23
Demonstrate the concept of a synchronous motor.
The power supply, operating at 8 volts, is connected to the armature coil through the double-ring comutator. The current reversing switch is used with the armature coil. Reverse the current twice per rotation as the device operates. This is tricky; you will have to practice to be able to get the rotation in sync with your manipulation of the current reversing switch.
K4, PS1