Switches are commonly used in keypads, human machine interfaces (HMIs) and other electronic devices. They are designed to control a circuit. Interacting with a switch will open or close a circuit, for instance. While some switches use a mechanical method of operation, though, others are touch based.
The Definition of a Touch Switch
A touch switch is a type of circuit-controlling device that, as the name suggests, operates via touch. Placing your finger against a touch switch will change the orientation of its circuit. The touch switch will revert from an open circuit to a closed circuit or vice versa.
The 3 Primary Types of Touch Switches
There are three primary types of touch switches: capacitive, resistance and piezo. Capacitive switches work by measuring capacitance. They apply a uniform voltage across the top layer, which they measure for changes in capacitance. Touching the top layer with a conductive object, such as a bare finger, will change the capacitance. The capacitive switch will then open or close the circuit.
Resistance switches work by lowering the resistance between two conductors. When you touch a resistance switch with a conductive object, its resistance will change. The resistive switch will then change the orientation of its circuit.
Piezo switches work by leveraging a piezoelectric panel. They convert changes in pressure to an electrical signal. Most touch switches use either capacitive, resistance or piezo technology. Of those three technologies, capacitive is the most common.
Advantages of Touch Switches
When compared to mechanical switches, touch switches offer several advantages. For starters, they typically last longer. Touch switches don’t have moving parts like mechanical switches. As a result, you can interact with touch switches without degrading them. Most touch switches will last for many years — all while providing you with an effective and reliable switching solution.
Touch switches are customizable. You can customize different design elements of a typical touch switch. Capacitive switches, for instance, are available with a Flexible Printed Circuit (FPC) or a Printed Circuit Board (PCB). You can also customize the overlay material — plastic, acrylic, glass, etc. — as well as the backlighting.
Touch switches are durable. They are designed to withstand harsh environments. If you’re looking for a switching solution to use outdoors, you may want to choose a touch switch. Whether it’s a capacitive, resistance or piezo touch switch, you can rest assured knowing that it’s durable. These are just a few advantages of touch switches.