Guides
As its name suggests, a limit switch regulates the operations of machines that are equipped with moving parts connected to a switching action mechanism. A wide range of industrial machinery uses limit switches to control the movement of devices performing on a production line, but these switches are also found in non-industrial applications, such as electric motor operation and garage door opener units. In the case of a garage door opener, a limit switch is responsible for turning off the motor that lifts the door before the door crashes into the lifting mechanism. The switch also deactivates the motor as the door closes, preventing it from being pushed into the ground. Limit switches enable this and similar operations to work as semiautomatic processes by regulating an initiated action to keep it within performance parameters.
Limit Switch Uses
When installed in a machine system, a limit switch can usually start, stop, slow down, or accelerate operations, as well as activate a forward or reverse process. In order to perform these actions, limit switches are designed in a variety of shapes, sizes, and capacity ranges to accommodate differences in machine systems and production processes. A limit switch is typically composed of a series of electrical contacts coupled to an actuator that controls the mechanical device responsible for on and off functions. Limit switch instruments are employed in a broad range of applications due to their straightforward design, relatively simple installation requirements, reliability, and resilience in withstanding environmental conditions.
Limit switch performance depends on a number of factors. In addition to the operational parameters and mechanical specifications of a machine, these factors include the size, mounting method, and force capacity of the switch, as well as the stroke rate involved in the operating process. It is important for a limit switch’s electrical rating to match that of the system into which it is installed in order to reduce the potential for instrument failure and ensure proper functioning. The common types of limit switches used in industrial applications include:
To better understand the way a limit switch circuit operates, it may help to look at an example that illustrates contact switching principles. A limit switch with a single-station, maintained contact design will have a “Start” button that mechanically controls the contacts. Pressing the “Start” button causes the mechanism to maintain the contact sequence that closes the circuit, while pressing the “Stop” button will open the contacts and break the circuit. If a system malfunction, such as power failure or overloading, causes the switch device to deactivate, the contacts will be unaffected and the motor will automatically reset.
For illustrations and information on the symbols used for designating contact sequences, visit Fundamentals of Electrical Engineering and Electronics.
With high quality products and considerate service, we will work together with you to enhance your business and improve the efficiency. Please don't hesitate to contact us to get more details of heavy duty limit switches.