What is a Limit Switch?

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Limit Switch is an electromechanical component that is used to detect the presence of an object. As the object contacts the actuator, the switch will cause an electrical connection to make or break. The limit switch then regulates the electrical circuit which controls the machine and the moving parts.

These switches are crucial for heavy-duty tasks, such as in lifts and commercial vehicle controls. They serve as sensors that record distance, measure temperature, or even protect circuits from exceeding limits.

Limit switches are available in a variety of switch configurations including Normally Open and Normally Closed, and come in various sizes, electrical specifications, and actuator heads. This ensures compatibility with diverse applications.

Limit switches are categorised into 4 main types:

WhiskerRollerLever

Plunger

Whisker type limit switch, rjs electronics ltd

Roller arm limit switch, rjs electronics ltd

Rod lever style limit switch, rjs electronics ltd

Plunger type limit switch, rjs electronics ltd

1. Whisker

These switches have a long, relatively strong spring-arm actuator which will bend and actuate the switch once sufficient perpendicular force has been applied to it. Whiskers are typically used to monitor the placement and flow of objects on a conveyor/assembly line.

 

2. Roller

Roller limit switches feature a roller on a stationary shaft that can transfer a radial force of an object to the thrusting force of the plunger. The roller element is used to reduce friction, but it is the plunging movement that actuates the switch.

 

3. Lever

The limiter on these switches is a lever mounted on a rotating shaft, and the switch will actuate once the lever has rotated around the shaft to a certain limit. Levers have a speedy response time, so they are perfect in systems such as lifts and door entry, etc.

 

4. Plunger

Plunger limit switches are the most commonly used type, as they are simple, durable, cost-effective and very versatile. They consist of a plunger that actuates the switch when an object pushes on it directly. This means that they require substantially less force to actuate.

What are the advantages of Limit Switches?

Limit switches offer a varied range of advantages. They are simple and easy to install and perfect for many industrial settings as they can switch multiple loads. Limit switches have a high level of accuracy and reliability with low power consumption.

What is a Snap Action Switch?

Micro switch, limit switches, electronics, rjs electronics ltd

The Snap Action Switch, or Micro Switch, is another type of limit switch available. Micro switches often have an actuating plunger which travels a small distance to trigger the contact sequence. It is actuated by a tipping-point mechanism.

Micro switches are much smaller than the standard limit switch, so one key benefit of these switches is that they can be installed into smaller/narrower spaces.

Applications

Limit switches are found in a range of settings, such as; commercial vehicles, agricultural equipment, cranes, industrial machines, injection molding machines, and more. We offer an extensive range of limit switches that can be installed in an array of different fields.

Micro switches are often used where there may be space limitations. Examples of applications include; car electronic equipment, communication equipment, test instruments, home appliances and medical equipment.

Did you know we provide many components for industrial controls? Discover more of our products for this sector here.

applications for limit switch, commercial vehicle, rjs electronics ltd

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