FLASHING_LED_FOR_LOW_BATTERY

Published:2009/6/29 22:54:00 Author:May | From:SeekIC

Developed for use in portable battery-operated test instrument to provide visual indication that depletion level has been reached for series arrangement of 24 nickel-cadmium cells providing 32.5 VDC for regulator of bipolar 11-V supply. Instrument must then be plugged into AC line for recharging of batteries. Voltage across B1 (nominally 32.5 V) is sensed by R1-R4 and D1. When level drops 24.1 V, opamp comparator output goes positive and enables gate IC2, so blink clock (such as low-frequency TTL-Level oscillator) makes LED flash. Audible alarm is optional.-R. T. Wamer, Monitor NiCad's with This Low-Battery Detector, EDN Magazine, April 20, 1976, p 112 and 114.



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