How to make a touch switch for 220v lights using a relay board and mosfet transistor
It is a very easy project and safe because the main 220v power is isolated from the dc 5v power
But first, let's take it step by step
Step 1: What Is a Touch Switch
A touch switch is a type of switch that only has to be touched by an object to operate. It is used in many lamps and wall switches that have a metal exterior as well as on public computer terminals. A touchscreen includes an array of touch switches on a display. A touch switch is the simplest kind of tactile sensor.
A capacitance switch needs only one electrode to function. The electrode
can be placed behind a non-conductive panel such as wood, glass, or plastic. The switch works using body capacitance, a property of the human body that gives it great electrical characteristics. The lamp keeps charging and discharging its metal exterior to detect changes in capacitance. When a person touches it, it increases the capacitance and triggers the switch.
Step 2: What Is a Relay
A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are also used, such as solid-state relays.
Relays are used where it is necessary to control a circuit by a separate low-power signal, or where several circuits must be controlled by one signal. The first relays were used in long distance telegraph circuits as amplifiers: they repeated the signal coming in from one circuit and re-transmitted it on another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations.
Step 3: What Is a MOSFET
The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a type of field-effect transistor (FET), most commonly fabricated by the controlled oxidation of silicon.
It has an insulated gate, whose voltage determines the conductivity of the device. This ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. A metal–insulator–semiconductor field-effect transistor or MISFET is a term almost synonymous with MOSFET. Another synonym is IGFET for insulated-gate field-effect transistor.
Step 4: 220v Touch Switch Ligh Circuit
In order to make this 220v touch switch light circuit, we will need:
-Mosfet transistor IRFZ44N
-2Relay module board LINK here
And some electrical wire, isolation tape, and some bulbs to test it out
We have all the necessary and we know what is all the components we can now start building our 220v touch switch relay-activated device so follow the next steps...
Step 5: Connect the Load(220v Bulb) to Relay Output
are interested in the input and out pins .In this step, we will speak about the output pins because is the easiest one.
The load in our case is a 220v bulb we will connect in series with the output pins of the relay module.Each relay from this board has 3 pins ON1/2 com 1/2 and NC1/2.
In this project, we will use the relay 2 so we will use ON2 and COM2 if you want to use relay 1 you got it
you will use ON1 and COM1.
Step 6: Input Part of Our Relay Board
Still to the relay board but to the input part now it gets interesting because the input has several pins but for simplicity, we will use just 3 of them.As you can see in the picture above from left to right we have the following
JD-VCC, VCC, GND GND, IN1, IN2, VCC
Ok first 2 pins from the left as you can see are connected with a jumper so we will let them like so we will move to the next pins GND is our - (negative terminal 5v) VCC is our + (positive terminal 5v) and the IN2 pin we will use like so: When we will touch the IN2 to GND the relay is on so lets test it before build it...
Step 7: Homemade Touch Switch
In order to make this you have to watch the instructable about the touch switch how i make it.
This touch switch has 3 pins output the green is load, Black-positive, Blue-negative so we will connect the touch switch to the relay board like this Green to the IN2 of the relay Black to VCC and Blue to GND and we will power everything with a 18650 Li-ion cell
Step 8: The Final 220v Touch Switch
If you did follow till now you will make your own 220v touch switch light circuit with less money and you will learn some interesting stuff on the way.
<< You have to be very careful when working with mains 220v/120v it is very dangerous!! >>
Thanks all for watching and stay tuned more projects to come all the best!