| 摘要 |
<p>An electronic overload relay 14 has an intrinsic power supply connected in series with the NC contact 16a of the relay between wire attachment terminals 26 and 28. The power supply is a parallel connected zener diode Z1 and capacitor C1, connected to the processor 16 in parallel with a low voltage sensing circuit 34 that detects the charge on the capacitor, whereby the processor operates to turn on a unijunction transistor Q1 for low voltage coil applications to shunt the power supply during contactor 12 closing and turn off a predetermined interval later by which time the contactor 12 should have closed. <IMAGE></p> |
