The article provides a simple egg timer circuit or a kitchen timer circuit which will sound a small in-built buzzer as soon the preset cooking time for the specific recipe is elapsed. In other words you may no more have to face issue of burned food, or overcooked food, or over boiled eggs in your dining table, once this egg timer is installed.
One of the many problems of camping is that of the indecision surrounding how much to pack.
Most people become victims of either overpacking or underpacking. One of the things you do not need is an egg timer but it is a nice useful device to possess.
Moreover, it is quite versatile in that it does not need to have a portability purpose only. You can easily use the compact egg timer described below at home if you do not have an extra socket for an electronic one since this runs on battery.
How the Circuit Works
Now half portion of the IC 556 timer runs the buzzer. It essentially works as an astable multi-vibrator, with an oscillation frequency of 2 kHz. The other half of the IC is the part of the timer that controls the timing.
The process is kicked off by the connection of the trigger input of the IC by S3 to ground. The Pl/R3/C network decides how long the timing pulse will be. In the prototype, C was made up of 47 μF/6 V capacitors connected in parallel.
The capacitance adds up to 300 μF and buzzes at 6 1/2 minutes when P is in the mid-position.
S1 functions as the power switch here. If this is the ‘on’ state, then the timer is reset by pressing S2.
The time to be clocked is fixed using P1 while S3 starts it. You can also use S2 to reset it in the event of a false start.
About 23 mA current is used up. You can also calibrate and install a scale behind the dial of P1 for ease of use.
The complete circuit diagram for the proposed egg timer circuit is given below: