universal timer


Posted on Feb 4, 2014

The time interval of this circuit can be varied digitally through the DIP switches. The time code however must be set in BCD form. A 120 Hz signal generated by doubling the line frequency is used as the time reference. This is then divided to 1 pulse per minute by the ICs 1 and 2. The counter IC3 counts backwards- that means it starts to count fro


universal timer
Click here to download the full size of the above Circuit.

m the value set by the DIP switches going back to zero. Pressing the start switch starts the counter and at the same time the triac is triggered into conduction. Once the counter reaches zero, the triac is switched off and a tone is generated. The stop button offers the possibility of forcibly stopping the counter in the middle of a counting process.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Dark-activated 230V Lamp
    Bench Power Supply circuit
    HiFi stereo preamplifier with tone control
    Tape recorder position indicator-controller
    Infrared Remote Controller
    Dome Drive Schematic
    Stable amplification 1001 times chopper amplifier



    Top