My thought was if it was a DC-DC voltage step-up device, it would not be good for the life of the motor.
If they advertise that it doubles the speed, it might very well be that the device doubles the voltage. No doubt in my mind the motor life will suffer. And, it would be unethical to try to get a warranty replacement on a motor burned out after using that device.
Hi Roger,
The speed of a non-synchronous motor has a highly non-linear relationship to applied voltage. The mechanical
power output of a motor is directly proportional to the
current through it. The WT140 Window Turbo monitors and regulates motor current, not voltage. As a result it will never double the voltage, and because it is mainly compensating for resistive losses in the wiring and switches, it does not increase current past the GM window system design specification. If it did the 30 A breaker GM designed into the system would be inadequate, and we actually retain that breaker in the Window Turbo harness.
The main failure mechanism for a DC brush motor is commutator damage due to insufficient speed and subsequent commutator arcing and overheating. In the case of our GM G-Bodys, there are a few reasons the window slows down, namely resistive losses in the harness, switches, etc and thickened grease.
The stock setup shortens the motor's life in three major ways:
1) By running heavily loaded at a low speed which causes brush/commutator arcing.
2) By keeping full voltage applied after the window has reached it's upper or lower stops. In a stock setup the only current limiting is the 30 A breaker. When the WT140 is installed, the maximum current at end limits is limited to a fraction of this, greatly reducing brush arcing on a stationary commutator.
3) Longer time to complete window movement. Using the WT140 the amount of time the motor is actually running is halved as well.
All factors considered we believe the WT140 will not shorten and may actually extend motor life. The current-regulation methodology the WT140 implements is what industrial controllers use when reliability is paramount, as opposed to the undersized wiring and switch approach used by GM as a cost-cutting measure.
Sorry this post is so long, but I have spent 30 years designing and analyzing these DC brush motor controllers in industrial applications and it is a subject I am passionate about, so I welcome all questions!
Cheers,
Howard Hoyt
www.proraceeng.com
