Any experience with power window motors?

[Funkehed]

Hi
I'm looking for a motor with a worm gear for a monitor leveling application. I thought that a power window motor would be a good choice for it.
I tried to drive a **broken link removed** with different drivers (including a 50A one) in both direction. I encounter the same problem with all of them - a huge dead band. It doesn't allow me to rotate the shaft smoothly. The rotation start at around 7% duty cycle. Even if I try to avoid the dead band by setting an additional offset when i need motor to start rotating it gives me kicks and very discrete shaft movement (especially considering use of two accelerometers in the system).

Has anybody used a power window motor or wiper motor which does not have this nasty effect? or at least have it very minimal.

 

[chuckey]

Some window motors have an inbuilt PTC to protect the motor against overload when trying to close an all ready closed window. I would take apart the motor to make sure that that there are no overcurrent devices fitted. For an application such as this, the current should be modulated not the voltage, try putting a resistor in series with it, see if the action is smoother.
7% voltage ~ .8V from a 12V battery, I think you are lucky to see it rotate at all. this figure is due to mechanical stiction.
Test that the armature stops randomly when the motor is run, if it does not, the the stop position is also the start position and will take the starting current surge.
Frank