|
Car Window Closer |
|
|
|
This circuit automatically rolls up a car’s
electric windows when it rains. The windows are rolled up one at a time while the system
monitors the window motor current. When the motor stalls, the system moves to the next window
and shuts off it’s the last window. |
|
|
|
The sensor is a pair of small bare wires
epoxied into the rain gutter. It only takes one drop of water to touch between the wires and
start the system. I used gold-plated wires (cut from precision resistors) to prevent
oxidation. |
|
|
|
I built the project assuming I would need
DPDT relays, but during installation, I found that SPDT relays were sufficient. In my car, the
window motor wires are grounded when no switches are pushed. Check the wiring in your vehicle.
You may be able to use smaller relays. |
|
|
|
Adjustment: |
|
First, turn R11 (time out) and R17 (stall
current sense) fully counter clockwise. Push the test button and adjust R11 clockwise to
the point where the window rolls up completely and waits about a second or two before moving
to the next window. Then adjust R17 clockwise to a point just past the point where the system
moves to the next window immediately after the previous one is rolled up. You may have to
change the value of the current sense resistors (R18, R19 and R20), depending on your car’s
window-motor current draw. |
|
|
|
Go to Circuit |
| |
