With a touch of the sensor wire X1, which can also be a pressure switch, the LED lights for a time that depends on C1 and R1. The time constant is 0.7 x R1 x C1, which can go up to more than half an hour with a capacitor of 1000uF and a resistor of 1M5. The supply can be done with voltages from 5 to 12 V. The LED can be of any type or color. The 555 CMOS can also be used, obtaining a low power circuit when on standby.
| Clique na imagem para ampliar |
