Hacked Gadgets Forum

December 17, 2014

The Useless Candle

at 1:02 pm. Filed under Funny Hacks

 

Remember the cool Usless Machine? Well now there is a Useless Candle. New idea but just as much useless fun. As soon as you light the candle the system detects that it is lit and blows it out. 🙂

“The control circuit for this project is built around a 555 timer IC. When light shines on the CdS photoresistor, the voltage at pin 2 drops below the trigger threshold. This sets the output at pin 3 HIGH and activates a power transistor. The power transistor then turns on the relay. After a short delay, the system resets itself and the output is turned off. The two capacitors are included to add a delay when turning the output on and off. The 100kohm resistor and the capacitor connected to pin 2 determine the delay in turning the output on. The fixed 10kohm resistor and the capacitor attached to pin 6 determine the delay in turning the output off. To increase either delay, you can increase the values of the resistors or the capacitors. To decrease the delays, you can decrease the values of the resistors or the capacitors. The power transistor is included so that you can activate relays that may exceed the power rating of the timer IC (200mA). The sensitivity of the sensor is set by adjusting the 10kohm variable resistor.”