Universal motor with braking circuit - has changeover switch with short circuiting armature winding or connecting in shunt circuit for excitation coil current interruption

摘要

The universal motor circuit has a switch (4) between the excitation and armature windings to connect these two windings in series. The switch of a changeover type which in its disconnect position short circuits the armature winding (3), or reverses the direction of the current in it. The switch is connected to a delay device which allows the excitation windings (1, 2) circuit or the entire motor to be disconnected, once the motor has stopped. In its disconnect position the switch connects a shunt circuit (6) comprising a resistor and a diode, into the field winding circuit. The dealy device may incorporate a capacitive relay in parallel to armature winding.