Polarity Switch

What's amatter with a dpdt switch?

thanks for the reply.

the window has it's own button to close either circuit. It would be quite inconvenient to manually switch the polarity with a dpdt (if I understand you correctly) first then open or close the window by using the original button, right? 

This won't work, and will destroy your MOSFETs. If you really want to use a MOSFET method then there you could try an integrated circuit such as this one: http://www.st.com/web/catalog/sense_power/FM1965/SC1039/PF149527

I'm not sure this is a good idea. I don't know about power window controllers but they may have protection circuitry that detect loads and auto reverse.

Thanks for the reply!

I don't have to use MOSFETs, any thing is good. The drive IC you gave is exactly what I need for this purpose, however, it is a bit more expensive than what I expected.

Any other good idea? A simple fix (if possible) would be ideal.

Thanks!

By the way, could you tell me why this won't work? It would be nice if I know cause of the problem.

There is so much wrong with the diagram I don't know where to begin : ( Permanently energized coils, high risk of MOSFETs shorting rails and no gate drive consideration.

There is no simple fix. The solution is a more complicated circuit, like the one mentioned. Also, that alone won't provide the safety features that the original controller may have had

(such as reversing the motor if a load is encountered while closing).

Thanks for your following-up.

The relay is not permanently energized if you read my first post. There are two grounds which either will be closed depending on the user pull up or push down the button. Only one ground point is closed at the same time. Because you cannot push the button while pulling it up. This circuit is a 'normally open' circuit. Please consider the two ground points as switches.

There is no 'reversing the motor' function originally within the controller, the only difference between the new one and the old one is the so-called 'one touch open/close' function which I don't even care about. The only thing that the original controller does is to reverse the polarity.

The Power (+12v) Supply is high current circuit which is separated from the window button, so no need for low-current to high-current drive.

How about this circuit. It would allow your switches to run relays which in turn would power the window up or down. This assumes that there are limit switches in the motor unit that will stop the window at top and bottom of travel. This way we eliminate the MOSFETs that were just confusing things.

John

It's Perfect! It's simple and effective!

Although I haven't try it yet, I have strong feeling that this will work.

Just ordered the some new relays. I will post back when I test this.

Thanks!