What are limit switches?
The limit switches presented here are electromechanical microcontrollers that are used in many industries. Most often they appear as limit microswitches and can be included in electromechanical microcontrollers. They are equipped with a housing that contains changeover contacts (the housing is also responsible for protecting the mechanism against external factors). Limit switches are small devices that detect movement and respond to changes in its range. They can be used in various applications, including in production automation as well as in building your own Internet of Things projects. An excellent example of the use of limit sensors and switches will be the construction of rotary tables, lever trucks, and hydraulic valves. They are a frequent component in automatic entrance gates to the property. They are responsible for determining the gate's end and start position. They control the position of objects also on product tapes, detect the position in other advanced machines.
These inconspicuous devices are really all around us. It is also good to mention that limit switches have many subtypes. There are even limit switches with a roller, a lever, without a lever, with a pin, with a rod, with a spring. Products can be made of various materials, but the most commonly recommended case material is high quality PVC.
How do the limit switches work?
What is the limit switches’ work principle? These devices are easy to use, but understanding the mode of operation is probably possible only with a basic knowledge of machine automation.
The operating principle of the limit switches is based on electromechanical switching of the movable contact position. This process occurs as a result of physical contact of the external object with the actuator, which exerts pressure on the limit switch lever. The switching threshold is modified by the user. When the actuator physically connected to the limit switch is rotated or moved, the result will be a change in the position of the given electrical contacts of the limit switch. Due to the fact that the limit switches have one stable position, two basic positions of internal contacts in a stable state are distinguished: contacts in the open position and contacts in the closed position (NO; NC).
Important advantages of the presented limit sensors are their long life, repeatedly high level of precision during switching, also in adverse environmental conditions. It is possible to switch high power electrical loads. The limit switch can be a key element in your project, especially if you are building an advanced IoT project.
Limit switches, reed switches and magnetic sensors – excellent components for alarm systems
One of the sub types of devices very close to the limit switches are Reed switches and magnetic sensors. You will find them in separate categories of the Botland store, but it is worth knowing that in many projects you will have to equip yourself with both reed switches and limit switches (limit sensors).
The reed contact is a switch whose position of the contacts is changed by applying a magnetic field source. This source can be a magnet or an electric circuit through which a sufficiently large current flows. In this situation, the contact system made of ferromagnetic material placed in a vacuum bubble in the glass bulb is short-circuited. As a result, the reed switch begins to conduct current in the electrical circuit of which it is a part. When the magnetic field source is removed, the reed switch contacts are opened. Open contacts mean a break in the power supply.
Reed switches and magnetic sensors are often mounted in buildings and are designed to activate an alarm or bell when doors or windows are opened. Together with limit sensors, they are used to build advanced and multi-functional property security systems and other IoT projects.