Timer Circuit With Buzzer Indicator

Listing ID #964095

Timer Circuit With Buzzer Indicator is used as portable parking meter timer and egg timer. The 14 stage binary ripple counter type IC 4060 has an on chip oscillator capable of stable operation over a relatively wide frequency is determined by an external RC network connected to pins 9, 10 and11. Our valued clients can avail Timer With Buzzer Indicator at pocket friendly price.
Circuit operation :
When the circuit is switched on with S1, the pulse at junction R4-C2 resets the counter and counting starts, when the count reaches bit 14 (Q14), pin3 goes high so that the self-oscillating piezo-electric buzzers, a 12V type is turned on via driver T1. The timer is powered by 9V battery. Light emitting diode D1 does not affect the operation of the circuit and is included merely to show that the timer works. Diode D1 and resistor R3 are, therefore optional components.  With the buzzer actuated, the timer draws a current of about 10 mA. Calibration: The time delay is set with aid of P1.Time delays of between one minute and two hours are possible by appropriate dimensioning of the timing components. 1 - 30 minutes: C1 = 220 nF; P1 =500K 1 - 60 minutes: C1 = 470 nF, P1 = 500K 1 - 120 minutes: C1 = 470 nF, P1= 1M