3 minutes timer circuit

Introduction

Timer circuits are always helpful in performing a crucial task exactly at the required time.  In our day-to-day life, people are busy and engaged in multifarious activities. In order to perform a specific task at a specific period and specific time, one needs to depend on timers. Here an awesome simple circuit designed as 3 minutes timing is given here for assembling and use. 

Specialities of the circuit

This circuit employs a single IC CD4093 which is commonly available in any electronics store. Apart from that, the circuit employs very few components for the construction. Low cost and low count of components make the circuit design simple and easy. 

The output of the timer is in audio form. Audio sound is generated from a buzzer that denotes the timing. The circuit is powered by a single 9V battery pack. Since the current consumption of the circuit when the circuit is in idle condition is negligible, the on/off switch is not included in the circuit. If one wants he/she can incorporate it easily in this circuit. 

Timing is determined by the resistive and capacitive components in the circuit. P1 and C1 are responsible to determine the exact timing of the timer. One can vary the time set by using the preset adjustment or by changing the value of the electrolytic capacitor C1. 

The circuit can be assembled on a general-purpose PCB and enclosed in a plastic box. 

Working

When push switch S1 is pressed and released the timer starts to functioning. After the timing period set by P1 and C1, the buzzer gives an audible sound that the time is elapsed. The component values mentioned in this circuit is set for 3 minutes timing. This can be changed to other timings by using the preset P1.  

The circuit schematic

Parts list

To sum up

A simple easy to build timer circuit with low cost will be beneficial for our many other projects. Pl. comment and share with others.