The so-called window switch is to use a servo motor to drive the glass up and down, which replaces the traditional rotating rocker lifting glass. It makes the lifting and lowering of the glass light, comfortable and automatic.
As we all know, every door of every car is equipped with a button for the window switch, press the glass upward to rise, and press the glass downward to descend. Some switches can also be jogged, that is, they can continuously rise or fall with a single tap. This function is more useful when paying at a toll booth. There is a master switch on the driver's door, which can remotely control the lifting of each door glass, and can also close the glass lifting mechanism of the whole car.
The lifting structure is the core component of the window system. Window Lifters
The window lifters of most cars use very flexible linkages to lift the window glass while keeping it level. Connect a small electric motor to a worm gear and several other spur gears to produce a larger gear reduction ratio, which provides enough torque to raise the window. An important function of the power window is that the power window cannot be forced to open-the worm gear in the transmission structure supports this function. Due to the contact angle between the worm and the gear, many worm gears have a self-locking function. The worm can rotate the gear, but the gear cannot rotate the worm, and the friction between the teeth causes the gear to join. The connecting rod has a long arm which is connected to a rod supporting the bottom of the window. The end of the arm can slide into the groove of the rod when the window is raised. At the other end of the rod is a large disk with gear teeth engraved on it, and the motor can turn the gears engaged with these teeth. Cars equipped with manual windows usually use the same connecting rod, but instead of turning the gear by the motor, the gear is turned by the rocker handle.
●Automatic lifting-the automatic lowering function is very common in cars equipped with electric windows. Press lightly and release the descent switch, the window will keep descending. The circuit used by this function can monitor the time the switch is pressed. If the switch is pressed for less than half a second, the window will continue to fall until it hits the limit switch.
If the switch is pressed for more than half a second, the window will stop descending when you release the button. Auto-rising windows are less common. The problem with the auto-rising window is that if anything blocks the movement of the window (such as a child), the window must stop, otherwise it will hurt the child. One way for car manufacturers to control the window force is to design a circuit that can monitor the speed of the motor. If the speed is reduced, the circuit will reverse the electrical energy to the motor, so that the window will fall.
●Control of the windows outside the car--In Volkswagen’s TV commercials, you will see that you can lower the window by inserting the car key into the driver’s door, turning and holding the car key. This function is controlled by the driver's door module, which monitors the door lock switch. If the time to turn the car key exceeds the set time, the driver's door module will lower the window.
●Some cars will continue to provide power to the window circuit after the flame is turned off. If you forget to roll up the window, you don’t need to insert the car key back to the ignition switch if you have this function. The power window circuit will install a relay that provides electrical energy on the wire. On some cars, the body controller will extend the time that the relay remains off by about one minute.