>From my (mostly 1990 and earlier car power window experince)
the window motors are on their own fuse. I would hang a reasonably
sensitive voltmeter across the fuse and see what I read when the motor
stalled. Note: Several months back there was some discussion
(no data) about why this wouldn't work.

Car fuses tend to run .010 to .050 ohms. If this works you could
clone the fuse to be a current sensor and save mucking with existing
wiring harnesses. IF the fuse works for this, the test voltage
is an offset from 12V (or the battery voltage) which causes some
processing problems, but the ground connection on many
on board motors is though the motor mounts or a 'local' in door
connection and has it's own interconnect problems. The trick
I would try is a 'current mirror' across the fuse using DIP transistors
(for Vbe matching) to reflect the signal to being near ground for
the PIC or whatever.  An opamp isn't much more expensive but
may have problems in single rail ~12v operations. Some assembly.....

Leaving children unattended in cars is highly unsafe and therefore
ILLEGAL most places I know.

R.Martin


Peter Marinsek wrote:

> Hello,
>
> I'm currently working in a car project where I want to drive opening and
> closing car windows (car alarm).
> And the question is:
> a simple circuit to detect when a DC motor is overloaded (when the
> window full close or full open the motor current increase)
>
> Thanks, Peter