Power Window

Description:Power windows use an arrangement of electric motors, drive mechanisms, switches and wiring to operate the windows.

Purpose: Power windows are a convenience feature that allows pushbutton control of the windows and centralized management of all windows by the driver. Many cars also use an express-down feature, which fully lowers the drivers’ window just by clicking a button.

Animation of window lifting mechanism at work, with inset of motor and gear reduction:


  • Obstacle detection with auto reverse feature
  • Window must be closed/opened within a limited time
  • Facility for driver to lock the passenger side windows
  • Automotive one touch up/down feature
  • Warning to close all windows when AC is turned on
  • Courtesy power on
  • Window Control from outside with a key in the driver’s door

Obstacle detection with auto reverse feature

Window must be lowered when it detects an obstacle in its path. When the window is being raised up, if there is any obstacle in its path then it must be stopped from further rising. Then the window must move in opposite direction by few centimeters. Here obstacle may be somebody’s hand or it may be a child leaning on the window.

Facility for driver to lock the passenger side windows

If there is a child sitting at the passenger seat, the child must not be able to operate the windows. This can be achieved by providing a lock key at driver side, which when pressed inhibits the child from accessing the windows.

Automotive one touch up/down feature

The automatic-down feature is common in cars with power windows. Tap and release the down switch and the window goes all the way down. Automatic-up windows are less common. The problem with automatic-up windows is that if anything gets in the way of the window, such as a child, the window has to stop moving before it hurts the child.

Courtesy power on

The power to the window circuit has to be maintained even after the car is turned off, which saves from having to stick the key back in the ignition if it was forgotten to roll the window up.

Window Control from outsidewith a key in the driver’s door

he windows must be lowered by inserting the key in the driver's door, turning and holding it. This feature is controlled by the driver's door module. If the key is held turned for more than a set amount of time, the driver's door module lowers the windows.


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