Limit switches

This product category includes limit switches (commonly referred to as limit switches). These are electromechanical devices, without which the functioning of many machines, devices or systems would be impossible. This accessory is used to limit the movement, i.e. to disconnect the system at the moment of reaching the final position. The limit switches function as a special sensor. They enable switching in electrical circuits and increase the safety of their operation.

Principle of operation of limit switches

Limit switches can be compared to traditional light switches. Their operation is based on disconnecting the entire device or control circuit when a certain position is reached. When a certain force is applied to the limit switch head, the contacts located inside the equipment open or close (depending on the type of switch).

Limit switches are always installed in a fixed (immobile) part of the machine, e.g. in the housing. You can meet them, for example, on the trolleys of machines or at the ends of the rails, preventing the device from exceeding the extreme position. This prevents damage to such mechanisms.

Limit switches – main features

Limit switches are small-sized accessories. They are easy to install, and a large selection of different variants of this product (different primarily in terms of the operating current and the shape of the limit contact lever) allows you to choose the right one for your needs without any problems.

Limit housings are usually made of metal or plastic. There are also models hidden in shells made of combinations of both of these materials.

The basic types of limit switches are relatively cheap accessories. Depending on the manufacturer and technical parameters, you have to pay from several dozen to just over PLN 100 for one copy. Miniature limit switches supporting extremely simple mechanisms cost even less than PLN 30. More complex models, intended for advanced work, are of course more expensive, and their price exceeds PLN 1,000.

Types of limit switches

There are several basic types of limit switches. Mechanical limit switches are the most popular. In their case, the contacts are activated by a movable head. This most often takes the form of a roller, head or pin.

An alternative to mechanical limit switches are the electromagnetic models. Limit switches of this type are commonly referred to as reed switches. Their operation is based on the phenomenon of magnetism. The contacts located in the main part of the circuit breaker react to a magnet which is located at the other end of the inside of the gear. When the two elements come close to each other, the contacts connect and trigger a specific reaction.

A special type of limit switches are the so-called microswitches. These are miniaturized versions of classic circuit breakers used wherever there is no space to place equipment of standard dimensions (e.g. on printed circuit boards).

Switch and limit switch – what's the difference?

Commonly limit switches are also referred to as sensors. However, to be precise, both attachments are two completely separate product categories. Both one and the other mechanism act as a switch (i.e. they react in a specific way to a phenomenon of a given value affecting them). Limit sensors have been additionally enriched with a warning element. The circuit breaker has the ability to provide information about the location of a possible obstacle in the operation of the circuit, but it will happen when it is cut off. The sensor sends a warning earlier, allowing the user to react accordingly.

Use of limit switches

Limit switches have a very wide range of applications and can be found in many machines and mechanisms. They are commonly used in industrial and construction automation. Without them, it would be impossible to operate most of the equipment or production lines used on a daily basis. Limit switches are also an extremely important safety element, e.g. in automatic garage or entrance gates. The accessories act as a sensor that determines the end position of the sliding element on the rail. It looks similar in automatic blinds. Limit switches are also installed in microwave ovens. There they serve as door opening and closing sensors. If these have not been pinched, the hardware will not be able to start. Microstops are installed, for example, in computer mice or at automatically activated light sources (e.g. at suspended shelves or cabinets). It is also worth mentioning their use as housing opening sensors. Many equipment or machines are equipped with this type of mechanism. Simply put – limit switches can signal leaks in the shells of the devices, or even prevent them from starting if a leak in the cover or housing is detected.

How to choose the right limit switch?

In order for the limit switch to be fully functional, it should be properly matched to the mechanism it is to operate. The cheapest models are designed primarily for amateur solutions. For more advanced technologies, more expensive and professional models should be used.

It is also worth paying attention to several important parameters. These include the supported current voltage, switch actuation speed, types of contacts (snap action, which act immediately or delayed, which react after a certain time), range of motion or number of cycles. It is also good to verify what the equipment housing is made of. For machines that are extremely exposed to fire, end caps in fire-resistant shells should be used.

Limit switches in the el12.pl shop

On el12.pl you will find limit switches of various types. We have both accessories designed for the simplest mechanisms, as well as advanced models for specialized use. It is possible to select limit switches in terms of the rated current and the number of poles possessed by a given product.

We offer limit switches from reputable manufacturers. The sale includes models of such brands as Promet or Schneider Electric.

Orders placed in the el12.pl store are usually completed within three working days. The exception is when the selected limit switches are not currently in our warehouses. During this time, the delivery of purchases may take up to several weeks. Information about the current stock levels and the approximate time of order fulfillment can be found on the card of each product next to its technical specification.