They should be mounted rigidly, be maintenance accessible, and have the side of the body with the cover screws facing outward. Limit switches should never be mounted in locations that could allow false operations by normal movements of operator or machine components. The cam should be of a shape that does not allow the actuator to receive a severe impact or that releases the actuator suddenly, allowing it to snap back freely. In many situations, such as a conveyor system, a cam is used to operate the actuator.
#Vex limit switch control how to#
But just as important is determining where and how to mount the switch. Mounting considerationsĬonsidering which type of switch to use is important when applying a limit switch. Commonly used in door jams to shut off power when opened. Returning the key to the hole deactivates the contacts. Once removed from the keyhole, the switch is actuated.
#Vex limit switch control manual#
While there are a number of different styles of limit switches available in the market today, this manual will describe two classes of limit switches - standard industrial oiltight and precision switches. The component containing the terminal screws or screw/clamp assembly necessary for wiring purposes. The component containing the electrical contact mechanism. In some limit switches, the actuator is attached to an operating head which translates a rotary, linear, or perpendicular motion to open or close the electrical contacts of the switch. The actuator is the part of the switch which physically comes in contact with the target. Most limit switches contain the following functional parts in one form or another. Repeat Accuracy : ability of a switch to repeat its characteristics precisely from one operation to the next operation Limit Switch Functional Parts : Total Travel : the maximum allowable distance the actuating ele-ment can travel Minimum return force (torque) : minimum force required to return actuator to its initial position Operating force (torque) : force required to move the actuating element Initial Position : position of actuator when no external force is ap-plied to the actuator Overtravel : movement of the actuator beyond the contacts trip point Release Point : the position of the actuator at which the contacts return to their original stateĭifferential : distance (degrees) between contacts trip and contacts reset Operating Point : position of the actuator at which the contacts snap to the operated position Pretravel : the distance or angle that the actuator must go through to trip the contacts
![vex limit switch control vex limit switch control](http://rharrison-engineering.weebly.com/uploads/3/8/5/2/38521703/8634702_orig.png)
![vex limit switch control vex limit switch control](https://store.robotmesh.com/media/catalog/product/cache/3b77bee5b8216d366fb1ee1544581c0c/l/i/limit_switch_3.jpg)
Inductive proximity, capacitive proximity, and photoelectric sensors perform this same process through noncontact sensing. Through this mechanical action, electrical contacts are either opened (in a normally closed circuit) or closed (in a normally open circuit). As an object (or target) makes contact with the operator of the switch, it eventually moves the actuator to the “limit” where the electrical contacts change state. The term limit switch is derived from the operation of the device it-self. Mechanical limit switches are contact sensing devices widely used for detecting the presence or position of objects in industrial applications. Other varieties of sensors/switches exist, including proximity sensors, light sensors, electric switches, among others. As the object makes contact with the actuator of the switch, it eventually moves the actuator to its “limit” where the contacts change state. Specifically, mechanical limit switches are switches that are mechanically activated, meaning that they have some sort of arm, lever, knob, plunger, etc., which is physically-or mechanically-activated by making contact with another object. Limit switches are a type of sensor that detect presence and absence. The sensors then produce an electrical output signal that can be used to control equipment or processes. Presence Sensing is the act of detecting the presence or absence of an object with a contact or non-contact sensing device.