This project is sensor based automatic water tap. The tap starts whenever anyone put his/her hand in front of sensor which is below the water tap.

The Ir sensor is made using 555 timer, used as astable multivibrator, vibrating at around 38 KHz. and another 555 timer ic is used as monostable multivibrator for tap circuit.

Step 1: Parts Needed

For Sensor Circuit

lm555 timer ic
103pf ceramic capacitor
18k resistor
1k resistor
22R resistor
102pf ceramic capacitor
IR led
4.7uf electrolytic capacitor
10k resistor
100R resistor
TSOP1738 IR receiver
red leds

For Main Circuit

12-0-12 step down transfarmer
1N4007 diode
LM7805
1000uf electrolytic capacitor
BT136 triac
LM555 time ic
red leds
1k resistor
10k resistor
103pf ceramic capacitor
100k resistor
100R resistor
BC547 transistor
Solenoid Valve (you can get one from old automatic washing machine)
Dotted PCB

Optional Parts

Wash Basin
wash basin stand
plyboard
Colors

Step 2: Circuit Diagrams

Here are both of the circuit diagrams for IR sensor and master circuit. I have also included eagle schematic files.Make both the circuits on different PCBs.

The Sensor Circuit

The sensor circuit is based on the 555 timer ic in astable mode. 555 timer ic vibrates at 38KHz and that waves are transmitted using IR led and if any obstacle is in front of IR led the rays reflects and the TSOP1738 IR receiver modules recieves and sends signal.

The Main Circuit

In main circuit 555 timer ic is used in monostable mode hence when it receives any signal from IR sensor then automatically enables the solenoid valve for some time and then automatically turn off the output current in BT136 Triac.