Microsecond CMOS Timer Up To Hours (CB1268E)

    This circuit uses a 4020 counter that divides the frequency up to 210, being found in a former American publication. Rx and Cx determine the timing steps and therefore the maximum time. The power supply can be made with voltages from 5 to 15 V. We found the circuit in documentation from the 70's, but it is quite current.





Circuit Bench