Windscreen wiper motor

Community General Discussions
1

Hi All,

Got my hands on 4 new windscreen wiper motors for 40 euro in total. Which should get me started with building something nice. The seller told me it is one for a VW Golf which I checked on other sites and they look the same.

Of course I opened it up and it has a couple of metal connections (see picture 'inside') on the gear wheel which connect to wires going to the outside (to make the wipers go left and right I presume. That would make a nice rudimentary odometer don't you think?

My PROBLEM (if it is...) NO SPECS

A) is there a method of measuring the currents necessary to determine the design of the power driver? And how much power would I get out of these things?

I did a rough test. just letting it run at 12V with no load and it drew about 1.5A. but the startup current must be much higher. The same for stall. How do you guys approach something like this?

B) alternatively I could buy something like http://www.pololu.com/catalog/product/755 and see where it ends up.

Regards,

DC

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2

Well the starting current

Well the starting current won’t be far off the stall current, and the stall current is easily measured by either:
• Clamp the motor stator and rotor so they’re totally fixed, supply a voltage to the motor, measure the current.
• Measure the coil winding resistance of the motor when it’s not rotating or connected to anything, then use Ohm’s Law (I=V/R) to calculate your maximum/stall current.

3

Yup…

Here is your motor driver (build this)

and Base Over Apex (who designed the motor driver) has done what you want to do…

 

I use this motor driver to run two dewalt drill motors on Walter with no problems. Walter draws close to 45 amps. The only issue with this motor driver set-up is that relays are used for reverse (which you don’t want to engage at full speed) --I have this issue solved in code and have had no problems. It really is a rock-solid motor driver, high amps etc.

4

Excellent! thanks
Excellent! thanks