Jogging Timer Circuit Diagram

Jogging Timer Circuit Diagram

3V Battery powered, Beeps after a fixed minutes delay

This circuit was developed since a number of visitors of this website
requested a timer capable of emitting a beep after one, two, three
minutes and so on, for jogging purposes. As shown in the circuit
diagram, SW1 is a 1 pole 9 ways Rotary Switch. Setting the switch in
position 1, the Piezo sounder emits three short beeps every minute. In
position 2 the same thing happens after a 2 minutes delay, and so on,
reaching a maximum interval of 9 minutes in position 9.

Circuit diagram:

Circuit

Parts:

  • R1_____________47K 1/4W Resistor
  • R2_____________10M 1/4W Resistor
  • R3______________1M 1/4W Resistor
  • R4_____________12K 1/4W Resistor (see notes)
  • C1,C3__________10µF 25V Electrolytic Capacitors
  • C2____________100nF 63V Polyester Capacitor
  • D1___________1N4148 75V 150mA Diode
  • IC1____________4093 Quad 2 input Schmitt NAND Gate IC
  • IC2____________4060 14 stage ripple counter and oscillator IC
  • IC3____________4017 Decade counter with 10 decoded outputs IC
  • Q1____________BC337 45V 800mA NPN Transistor
  • SW1___________1 pole 9 ways Rotary Switch (see notes)
  • SW2___________SPST Slider Switch
  • BZ1___________Piezo sounder (incorporating 3KHz oscillator)
  • B1____________3V Battery (two 1.5V AA or AAA cells in series etc.)

Notes:

  • Needing only one time set, rotary switch can be replaced by an hard-wired link.
  • A DIP-Switch can be used in place of the rotary type. Please
    pay attention to use only one switch at a time, or the device could be
    damaged.
  • Varying R4 from 10K to 15K you can obtain more or less than three short beeps after the preset time delay.
  • To obtain a one-second beep only, after the preset time delay,
    disconnect pin 9 of IC1C from pin 9 of IC2 and connect it to pin 8 of
    IC1C.

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