摘要:
An isolation monitor is disclosed in which a switchable bias voltage is imposed on a chassis ground. An isolation voltage is measured when a bias voltage is applied. When there are no electrical faults, the isolation voltage swings up and down to known values. When a fault occurs, the isolation voltage will not to swing to the known values, and thus the isolation resistance can be measured and alarm generated if the isolation resistance falls below a threshold value.
摘要:
Circuits, systems, and methods are disclosed to eliminate the requirement for an external electromechanical contactor. Integrating contactor circuits with a motor controller reduces cost. Additionally, the cost of the contactor circuit may be reduced by providing transistors designed to block current in only one direction in the event of an electrical fault corresponding to an electrical drive direction.