Egg (Timer) on Bread (Board)
This is an egg timer circuit that sounds the alarm when your egg is ready. You can choose between:
- soft (3.5 minutes)
- medium soft (5 minutes)
- medium hard (7 minutes)
- hard (10.5 minutes)
The Circuit
The timer circuit is based around the CD4060 IC. I used this CD4060 tutorial to figure out how long it takes for each output to go high. Then I used AND gates to combine different outputs to get the four different time settings.
The LED is there to give you an indication that the counter circuits is working.
Parts List
Battery
9V
C1
0.22 µF
Q1
nMOS
R1
1 MΩ
R2
100 kΩ
R3
1000 Ω
SW1
Rotary (4-position)
U2
CD4081
