Jogging Timer

3V Battery powered

Beeps after a fixed number of minutes

Circuit diagram

Jogging Timer-Circuit diagram

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.)

Device purpose:

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 2 minutes, and so on, reaching a maximum interval of 9 minutes in position 9.

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. Pay attention to use only a 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.
author: RED Free Circuit Designs
circuit from http://www.redcircuits.com/