Single Touch ON OFF Switch Circuit
ON- OFF Any Appliance Using Single Touch Plate. in this circuit Two ICs are used, One is 555 timer ic, and the second is D-Flip-Flop 7474 ic. When Once Touch the touch plate, The Light is ON, Again If you Touch The Light is switched OFF. You can say that ON-OFF using One Touch Plate or ONE TOUCH POINT this circuit. This Single Touch ON-OFF of this circuit makes it very interesting And Useful. You can use the BC547 Transistor at the place of 2N2222.
• First Touch = ON
• Second Touch = OFF
Components
IC
LM555-1
7474-1
Transistor
BC547-1
2N2222-1
Capacitor
0.1uf-2
10uf-1
Resistor
100k-3
330Ω-1
100Ω-1
Diode-1 (1N4007)
Relay-1
Must Read Automatic Water Pump Controller
Hey Aman, I am planning on building your Single Touch ON OFF Switch Circuit and was wondering if I could replace
Q2: 2n2222A that drives the coil of the relay and the LED with a beefier transistor or mosfet? I have on hand an IRF510 NPN, a IRFZ46, and a few others. Would that work and would I have to change R6 as well??? I am wanting to eliminate the relay and just use a higher amperage transistor or mosfet to turn on some LED’s. My total current won’t be but a little over an amp. Will the 7474 IC handle 12 volts instead of the 5 volts supply? If not, I’ll just use a 7805 VR.
Also, by the way I am reading your schematic, is R2 a 100k trimmer pot to adjust the sensitivity for the touch plate?
According to datasheet maximum supply voltage for 7474 ic is 5.25 to 7v so use only 5v. you can use 7805 for 5v
Thanks for your reply. I really appreciate it.