What Is a Window Limit Switch?

Limit Switches

• Limit switches help keep eclectically controlled systems within their safe limits of operation. For instance, a furnace may come with a limit switch. This switch ensures that the heat within the furnace stays below a predetermined maximum temperature. A limit switch circuit stays closed during the normal operation of a furnace, and it opens if the unit reaches unsafe temperatures. The opening of the circuit initiates a process that turns the furnace off. Limit switches generally use relatively simple circuit systems.

Window Limit Switch

• Window limit switches ensure the safe operation of automatic windows. Assume you install automatic windows in your home. These windows can only move so far into the walls of your house before they hit a part of the frame. Such a collision may damage the window, your home’s frame, or both. A window limit switch senses how far a window can safely open and stops the window if it reaches its limit. When an automatic window reaches its limit, the limit switch circuit opens, preventing the window from moving further.

Car Window Limit Switches

• Cars contain numerous limit switches. These switches prevent steering wheels from turning too far in either direction, stop automatic antennae from rising too far from the vehicle and control automatic windows. Limit switches on automatic windows prevent windows from raising or lowering beyond a certain point. They accomplish this by stalling the engine that raises or lowers the window when they reach a predetermined point. No matter how hard you hit the open or close button for an automatic window, the limit switch does not allow the window engine to restart.

Setting a Window Limit Switch

• With some electrical know-how you can set the limit switch for your car window. Setting a switch allows you to roll a window all the way down or up with a single touch of a button. You can also program a window limit switch not to allow this. Advanced programming allows unorthodox operation of windows. For instance, you can, ostensibly, program your limit switch to only allow your window to rise halfway before stalling. This function appears in cars with back windows that only roll part way down, for child protection.