VOLTAGE LOSS DETECTOR

摘要

PATENT Case 850428 VOLTAGE LOSS DETECTOR Edmund O. Schweitzer, Jr. A detector for indicating loss of voltage on a monitored conductor includes first and second serially connected capacitors, and a rectifier circuit which derives operating power from the monitored conductor to charge the capacitors in the presence of voltage on the conductor. A forward-biased diode connected across the second capacitor limits the voltage developed across the second capacitor during charging to a relatively low level. Upon loss of voltage a portion of the charge in the first capacitor is transferred to the second capacitor, causing the voltage across the second capacitor to reverse polarity and progressively increase. This causes an enhanced field effect transistor connected across the capacitor to become conductive and discharge the first capacitor through a relay or other indicating device to provide a control effect indicative of voltage loss.