Pressure relief window system

Discussion in 'Automotive Electronics' started by Glen M, Jan 12, 2016.

  1. Glen M

    Thread Starter New Member

    Jan 12, 2016
    Hello all, this is my first post and I'm looking for some help in designing a circuit.

    Firstly let me say I enjoy basic electronic projects but to date my experience has been limited to simple lighting circuits and modifying consoles for a/v outputs etc. Simple connect wire from here to here stuff.

    I want to design a circuit that will open the windows of my car by say 2cm when the door is opened then close the window when the door is closed. I was thinking of using the door courtesy light as a trigger. This is a light in the door that only comes on when the door is opened. My intention was to use two relays as in one normally open and one normally closed to operate as follows:

    Door opened +12V from courtesy light to both relays.
    Normally open relay closed starting timer to run window motor for 1 second (or whatever time needed to drop glass by 20mm)
    Normally closed relay opens resetting second timer

    Door closed, courtesy light off.
    Normally open relay returns to open resetting timer
    Normally closed relay starts timer to run window for 1 second (or whatever time is needed to close window again)

    The glass on my car doors is frameless. At present when opening and more so closing the door you are pushing against the rubber seals effectively forcing them to 'pop' up and over the glass each time which is less than ideal. There is an aftermarket solution to this but its very expensive and I'm sure I can make something up for a fraction of the cost.

    I have been looking at various 555 timer circuits but the struggle seems to be having a momentary switch. My triggers are going to be either constant 12v or no 12v. With a constant power supply the 555 timer seems to repeat itself over and over which obviously won't work.

    It might be too much to ask for someone to design this circuit out for me but I would be grateful of any advice.
  2. shortbus

    AAC Fanatic!

    Sep 30, 2009
    Since the windows were originally engineered to work the way they do, don't understand why you think it is so bad. They have been working fine since the days of the first "hardtop" cars, even though the original weather seals weren't near as good as the ones today. I have a 1957 Buick Century with the original weather strips and windows that still seals fine. This sounds like a solution in search of a problem.
  3. nerdegutta


    Dec 15, 2009
    Hi, and welcome to AAC.

    The 555 timer can be in astable mode or in mono mode. Here's a great site about the 555 timer IC.
  4. Glen M

    Thread Starter New Member

    Jan 12, 2016
    I understand the car was manufactured in such a way as to not require such a modification however I would suggest that Hyundai didn't include the feature because it would just cost to much. This is a common feature on BMWs and Mercs. The aftermarket relay kit to do it costs in excess of $100 which I personally think is a bit much for all it achieves.

    I'll take a look over that website suggested thanks.
  5. tcmtech

    Distinguished Member

    Nov 4, 2013
    To me that sounds like your up travel limit for the glass is set too high and needs to be adjusted down a bit or your door hinges are tweeked.