60_LED_HYPNOTIC_SPIRAL

Published:2009/7/7 20:50:00 Author:May | From:SeekIC

LEDs are mounted on display board in spiral arrangement and wired in matrix connected to ICs so each LED is lighted in sequence as IC1 and lC2 carry out counting function. IC3 is square-wave oscillator with frequency determined by C1 and setting of R2. Output pulses are used to clock lC1 to advance count, with carry output of IC1 clocking every tenth count. At end of 60 counts, both ICs reset to zero for new sequence. Inherent current limiting of ICs makes dropping resistors unnecessary for LEDs.-F. Blechman, Digitrance, Modern Electronics, Dec, 1978, p 29-31.



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