STROBING_LED_DISPLAY_1

Published:2009/7/1 23:56:00 Author:May | From:SeekIC

Sequential strobing of individual LED displays, at rate fast enough to eliminate flicker (about 10% duty cycle), cuts power requirements of LEDs and eliminates need for power-wasting resistors in series with digit segments. Circuit uses 7492 binary counter connected to divide by 10, continuously clocked by 1000-Hz signal from external counter time base. Each of the 10 counter states is decoded by 7442 decoder for use in turning on PNP switch transistor connected in series with anode of each 7-segment LED digit. Digits are thus turned on fol 10'/0 of time at 100-Hz rate.-B. Hart, Current-Saver Counter Display, 73 Magazine, June 1977, p 174-176.



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