What is a limit switch?
A position switch is often referred to as a limit switch, limit position switch, limit switch or limit switch and is a sensor that detects when a moving object, such as a workpiece or machine part, has reached a certain position. The signal generated can be transmitted electrically, hydraulically, pneumatically or mechanically. Sequence control in mechanical engineering consists of several work steps in which a position switch detects the end of a movement and thus initiates the next step in the sequence. Limit switches are standardized according to EN 50041 and are therefore absolutely reliable. They are also used as safety switches (e.g. door closing) to prevent personal injury and machine damage.
How a limit switch works
When an object, e.g. a moving object (the safety door on a machine) comes into contact with the actuator, an electrical connection is made or broken. Via these contacts, the limit switch can detect the position of the object in order to generate and forward a signal (e.g. to establish an electrical connection). This means that if the door of the machine is simply opened during operation, the circuit is immediately interrupted and serious work accidents are avoided.
Robust and durable, thanks to high-quality material
Limit switches must meet certain requirements. Therefore, it is important that they are made of high-quality materials. Since limit switches are part of the electrical installation, they must first withstand high mechanical loads. The material that resists electronic charging is ABS plastic. ABS (acrylonitrile-butadiene-styrene copolymer) is an engineering plastic that is particularly suitable for position switches. The material is not only resistant to mechanical stress, but also to grease and oil. Good temperature resistance and resistance to household acids are also criteria that plastics meet, making them ideal materials for limit switches. In combination with other strong and high-quality materials, the limit switch is extremely durable.
Are there different types of limit switches?
Yes! Position switches come in a wide variety of designs. Depending on the purpose for which you need a limit switch, you should choose the appropriate switch. In our extensive assortment you will find different designs for every kind of use. Here is a small listing. Limit switches are for example roller lever switches. Here the actuating head is equipped with rollers. When contact is made with the roller, for example by a machine part, the camshaft in the roller lever switch rotates and actuates the contacts. Limit switches also include proximity switches, also called proximity switches. As the name implies, these switches respond to proximity, i.e., no direct contact. In everyday life, a proximity switch is responsible for turning off the screen when you are on the phone and hold your smartphone to your ear. Photoelectric switches are also limit switches. These identify a specific location, such as a person or object between two elevator doors, before signaling that they can close automatically if there is nothing between the doors.