What Is a Microwave Switch?
Microwave Switches are components that detect the position of an object and provide a contact output. They are mainly used as switches for detection, but may also be used for operation.
The contact output of Microwave Switch is incorporated into a control circuit to operate or stop a machine. Microwave Switch contacts themselves generally have an allowable current of about several amperes. The part that comes in contact with an object has an actuator, which can be a button, roller, or lever type.
Uses of Microwave Switch
Microwave Switches have a snap-action mechanism and are characterized by their high accuracy in detecting position.
They are used in door interlocks, safety switches for vending machines, microwave ovens, elevators, and industrial equipment. They are also used in sensors that detect the opening and closing of printers and other equipment.
Sizes are classified into four types, from general type to ultra-miniature, and are available in reverse action type for locations subject to severe vibration or shock, magnetic quenching type for applications requiring stable operation of DC circuits, and immersion-proof type for high sealing performance. They have a wide range of applications from industrial equipment to home appliances.
Principle of Microwave Switch
Microwave Switch is divided into five parts, and the movement of the actuator leads up to the contact point.
1. Actuator Part
External force or motion is transmitted to the internal mechanism. The actuator is connected to the snap-action mechanism, which can be a button, roller, or lever type.
2. Snap Action Mechanism
It consists of parts such as a spring, a movable piece, a common terminal, and a receiver. When the force applied from the actuator increases, the movable piece and spring move the contacts.
3. Contact Point
There are two types of contacts: normally open and normally closed. Generally, each Microwave Switch has one of these contacts, but some have only one. There are crossbar type and rivet type contacts, and they are used according to the voltage and current of the circuit. Gold, silver, or plating is used as the material.
4. Terminal
Terminals connect the switch to the circuit. Terminals are available in soldering, connector, screw-tightening, and printed circuit board types, and the connection method is selected according to the application.
5. Case
The case protects the circuit and mechanism, and the resin is selected according to the required mechanical strength and heat resistance.
Uses of Microwave Switch
1. Doors and Printer Open/Close Covers
Microwave Switches are used to detect the position of doors and covers. Microwave Switches with actuators that have a wide range of shapes are used. Microwave Switch can be installed in a limited space.
2. Detecting the Opening and Closing of Dishwasher Covers and Washing Machine Lids
Microwave Switches are used to detect the position of covers and lids. These devices may be exposed to water, so Microwave Switches are waterproofed.
3. Mouse Operation Input
This is used in a mouse not as a position detection switch but as an operation switch. Microwave Switch detects mouse clicks and outputs them to the computer.
Other Information on Microwave Switch
1. The Difference Between Microwave Switch and Limit Switch
Microwave Switches and Limit Switches are often confused with each other. Limit switches, like Microwave Switches, are used as detection switches, but there are differences in construction and application. Limit switches consist of a built-in Microwave Switch in a plastic or metal case.
Limit switches are used to improve weather resistance when exposed to rainwater. Limit switches are also used in some industrial facilities as a measure against dust and oil.
2. Snap-Action Mechanism of Microwave Switch
A snap-action mechanism is a mechanism that quickly switches the movable contacts regardless of the speed at which the switch is operated. In contrast, a mechanism in which the operating speed is the moving speed of the movable contacts is called a slow-action mechanism.
Microwave Switches with snap-action mechanisms are characterized by a fast switching speed of the contacts, which minimizes arcing between the contacts. Even small Microwave Switches can have long contact life and excellent durability.