Reflex Timer Circuit

Posted on Aug 8, 2012

This timer circuit uses a 555 IC timer and three 74LS193 counters to drive an LED display. SI is activated by one person, who turns on piezo buzzer BZ1 via Ql and also starts the clock; SI is activated by the other person being timed.

Reflex Timer Circuit
Click here to download the full size of the above Circuit.

This shuts off the timer, and the number of LEDs lit indicate, in binary form, the elapsed time.

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