Beefing up my servo

[ingram010]

Hi All

I want to beef up my servo.  My idea is to remove the pot and motor from the servo, run the outputs (the ones originally attached to the small motor) through a more capable H-Bridge to drive a windscreen wiper motor, and link up the pot to the wiper motor.  In essence I think this should work but I am not absolutely sure.  If any one has any suggestions please let me know, as I don’t want to start buying and building if I am barking up the wrong tree.    

Regards

Ingram010

[Trumpkin]

ummmmmm why not just use an H-bridge? Why would you still need the servo circuitry?

[ingram010]

Hi Trumpkin

I was under the impresion that servos have an input pulse that varies in length every 20ms or so and that the output is just a repeated pulse that varies in length.  The more frequent the pulse the faster the motor runs and the slower the pulse the slower it goes. Then the pot is there to feedback the motor position.   I am no expert so I apologise for seeming ignorant.

Cheers

Ingram010

[ingram010]

Oh, and also there is the feedback circuity. I am assuming that it would be easier to it this way.

ingram010

[hudbrog]

Nice idea, but damn hard to implemet. Otherwise, why would people buy high-torque servos, if they could easily modify cheap motor that way...
Electrically it is easy. Mechanics needs a lot of thinking (and skills) to do properly.

[ArcMan]

I agree with hudbrog, but given that, you may want to consider forgetting about kludging it by using servo guts for your control.  Just use a microcontroller along with an H-bridge and a position feedback device like a pot.

BTW, you may know this, but I had to learn the hard way.  The cases of many windshield wiper motors are tied to one of the motor leads - the "ground" lead.  But if your running the motor forward and reverse, the case becomes "hot" in reverse.  Also, the worm gear box on the one I had was not designed to run in reverse - so it would bog down when I tried to run it in reverse.