Self-Activating Universal Motor Brake
Original Publication Date: 1988-Jul-01
Included in the Prior Art Database: 2005-Feb-15
This article describes a circuit for driving a universal motor, both forward and reverse, as well as providing braking action in the forward direction to stop the motor quickly when the power is turned off. The circuit provides such control without a separate brake control input. The circuit is particularly suited to applications where the control electronics or microprograms have been previously designed without consideration for braking. This circuit can be applied with such programs or logic to provide braking without having to change the logic or programs which may be in object code form and difficult to modify. The circuit detects the removal of forward drive voltage to apply a low voltage shunt across the motor, causing rapid braking action.