What Is a Tape Switch?
A tape switch is a thin tape-shaped switch, also called a pressure-sensitive switch. It contains two thin electrodes, top and bottom, inside, and when force is applied in the direction of thickness, the contact points of the electrodes are connected and the switch is energized. In addition to its thinness, the length of the switch allows it to sense any position where it is pressed. Many of them have protrusions on the surface to facilitate response. A similar structure with a larger area is called a mat switch.
Some products are available in lengths from several inches to several feet and can be disconnected at any position by the user. Because of their wide detection range, they can be used for a variety of applications. Many products are thin and can be bent freely, making them suitable for curved surfaces. Lightweight, they can be easily attached with double-sided tape. Some products with waterproof treatment can be used in places where water splashes or outdoors.
Uses of Tape Switches
Since they can detect the passage of people and vehicles, they can be installed in corridors and window frames for security purposes.
In the case of emergency stop devices for factories and large facilities, they can be installed in areas that are dangerous to intrude into, and if the tape switches detect intrusion, it will stop the equipment. The low profile of the tape switches makes them unobtrusive even when installed in multiple locations. A similar application is the detection of doors, doors, automatic shutters, etc., for detecting pinching and opening/closing.
It can be installed on the bumper of an unmanned transport vehicle, for example, and used as an emergency stop device in case it comes in contact with something while in operation.
In hospitals and nursing homes, it is used to detect when a patient has gotten out of bed or other equipment. It can also be used to interlock tape switches with a nurse call, etc., to notify them. Since many products are bendable, they can be attached to curved surfaces, such as bed rails.
Can also be used as a foot switch for various devices. They are space-saving and convenient for multiple installations. Since the operating load can be selected, the ON/OFF sensing load can be selected according to the need for standing or sitting work, etc.
Principle of Tape Switches
The construction of tape switches consists of two electrodes, an insulator between the electrodes, and a vinyl outer covering (PVC or similar material) on the outside. To ensure strength, some switches are wrapped with nylon fiber between the vinyl exterior and the electrodes. Some products are made of vinyl with a vinyl exterior that is resistant to high/low temperatures and chemicals and can be selected according to the environment in which they will be used.
The principle of operation is that thin electrodes are placed on the top and bottom surfaces of the tape, and when a load is applied in the direction of the tape thickness, the thin electrode on the top surface curves to make contact with the electrode on the bottom surface, resulting in conduction. The two electrodes run from one end of the tape to the other, and can be placed on long surfaces because they can be activated by pressing any part of the tape except the ends. There are 2-wire and 4-wire types to choose from, depending on the application.
There are also mat switches with several tape switches inside a large mat-like sheet, which can detect a wide range of objects.