| 摘要 |
<p>An arc suppression device (40) for protecting the load carrying contacts (30, 31, 32) of a power contactor (20) includes gate controlled semiconductor devices connected in parallel with the contacts. A signal from a control circuit (45) causes gating current to be applied to the semiconductor devices nearly simultaneously with the application of current to and removal of current from the solenoid (25) of the power contactor. A source of gating current of sufficient magnitude and character is provided to gate each thyristor into the conducting state substantially immediately. The source of gating current may be either direct current or high frequency alternating current. Circuit means responds to the control signals to provide the gating current for a limited period of time prior to, during and following the closing of the contacts. Gating current is not continued after the contacts have closed to protect the semiconductors from possible damage. Additional circuit means responds to the removal of the control signal to provide gating current for a limited period of time prior to, during and following the opening of the contacts. An isolation relay may be provided to prevent leakage current from flowing through the semiconductor devices to the load while the power contacts are open.</p> |
