This circuit is based on learning of the discharge and charge of the C. This can be used as a timer circuit and can be applied in the OFF electrical appliances.
The application has also put relay instead of LED can be enabled.
This circuit is working as video below:
How it works
When we press the switch S1. It causes LED1 to be light told state ready.
Then, we press S2, which is a timer switch. On the press switch, the S2 current will flow to the C1 charge fully.
Then, to discharge out through R2 to limit current. To flow to the bias for transistor Q1.
Both Q1 and Q2 work together in Darlington Compound mode. To increase the current higher gain to drive the LED2 light up.
The LED2 is still overtime as C1 discharges all Q1 and Q2 stops LED2 is off if you want the timer circuit is longer. Then add the C1 and if you want a little time. to reduce it to C1.
10 Second Fan ON Delay Timer circuit using transistor
A friend of mine wants a 10-second delay timer circuit at can turn ON Fan 12V at use in an automobile. By fixing the period of time by about 10 seconds. He sets conditions that must use electronic parts to economize and seek ease with.
I then choose transistors and relay controls electric fan equipment follow the circuit in a picture. The value delays can fix with R1 and C1 which there is a formula that calculates 0.5 x R1 x C1.
When press S1 wait for about a 10-second relay then work turn on give the electric fan works. The detail is other seen in the circuit.
Buy components in this projects HERE!
GET UPDATE VIA EMAIL
I always try to make Electronics Learning Easy.