WAVE SWITCH||TOUCH LESS SWITCH USING 555

Hello everyone Welcome

Today I am building a simple touch less switch, it’s activated by just waving our hand with the help of Infrared sensor and 555 timer IC so let’s build it….

Its operation is simple as the 555 working as flip-flop its store the previses state of input and the output change each time when input gets changes

The 555 timer in bistable mode i.e. as a flip-flop can be used in low speed, non-computer applications like robotics. A simple application is a robot which moves forward and backward every time it hits an object.

That being said, the circuit of a flip-flop using a 555 timer is shown below.

Source :- https://www.electronicshub.org/wp-content/uploads/2015/06/Flip-flop-to-control-LED.jpg

When the output at pin 3 is high, the capacitor C charges through the resistor R1 to the peak value i.e. VCC. When the output at pin 3 is low, the capacitor discharges through the same resistor to 0. In order to switch the output from high to low or low to high, a switch is used at the junction of trigger and threshold pins.

The voltage divider formed by the resistors R2 and R3 will provide a voltage of VCC / 2 at the pins 6 and 2. When the switch is pressed, this voltage is interrupted and triggers the internal flip-flop. This will allow the output to switch between the two states.

Component list

1 x 555 timer IC

2 x BC547 transistor

2 x 10k resistor

2 x 1k resistor

1 x 220k resistor

1 x 220nf cap

1 x 5-volt relay

1 x diode 1n4007

A circuit that acts as a toggle flip-flop is shown below. It is used to light an LED and the LED switches between ON and OFF when the switch is pressed.

So, as I am using IR Sensor Module its give value high or low but I required to connect two pin like a switch, so I decide to use simple bc547(Q1) transistor as a switch as shown in the circuit diagram below. It just work fine in my circuit as high voltage apply to the base of the transistor, current star flowing from collector to base acting as a conductor