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Electronics gurus. Can I build a "capacitor" to take 12V to 15v? How?

Something to consider - inside the motor casing is a thermal/overload switch. If the motor starts draws too much current then the contacts open and the motor doesn't operate until they cool down and make contact again. Bumping up the voltage by 20% will make the motor draw 20% more current. If you start having issues with the motor cutting out then you'll know why.
 
I've been staying out of this one, because by the time I saw it, most options had been mentioned already.
As mentioned, you cannot use a transformer on DC, and a capacitor would not help unless it was a really huge one used as a voltage doubler.

However, window motors for these trucks are easy to come by used. And the duty cycle is really short.
Just for fun, I would like to see what would happen with double voltage.

I would not try it on a vehicle I was using, but if you had a spare complete door or a truck that you were parting out, it would be interesting.

Of course, you would want to keep your fingers out of the way of the glass, it might go up awfully fast.
And might even break.

Remember that scene in the Bond film with the glass door??

If it worked, then it would be fairly easy to add a second battery that would charge in parallel with the regular battery but be in series for the windows.

Or, if that was too much, then a pair of 6 volt batteries would charge in series and go to the motor in parallel for 18 volts.

Just a thought.
 
rampage said:
Something to consider - inside the motor casing is a thermal/overload switch. If the motor starts draws too much current then the contacts open and the motor doesn't operate until they cool down and make contact again. Bumping up the voltage by 20% will make the motor draw 20% more current. If you start having issues with the motor cutting out then you'll know why.
Click to expand...

Yeah, most of these motors have thermal protection device, but I don't remember seeing one in the motors I've opened for these trucks. Such devices aren't that hard to bypass anyway. Sometimes as they age the resistance goes up and the windows slow more. They are really a safety in case there is a head or arm in the window it should cut out. It seems like a self-resetting circuit breaker on each window would be acceptable, if the right value is available.

I did the relay mod and got something like 40% faster windows. IIRC, with stock switches and wiring the motors were seeing less than 9V. One nice thing about having more voltage on hand is that you don't have to go to super heavy wire to get voltage to the motors. The added current will wear out the switches faster, so doing the relay mod at the same time is a good idea. But part of the appeal of the over-voltage concept is that you could do most of it underhood and never have to open the doors up. Of course if you do this on a K5, you should also tie the tailgate window into the same system.

If you go from 12V to 16V, that's 78% more power.
 
Fordum said:
Just for fun, I would like to see what would happen with double voltage.
Click to expand...

Maybe somebody with a Military version can move that circuit over to the 24V side. And take a video. They might end up shutting off the engine to roll up the windows, for fear of breaking the glass.

It might actually be awesome for the tailgate window.
 
I need a new motor anyway. I would like to try it, but i really dont want to double the voltage. I just want 16v. And i really dont want to fuss around with anything other than having it be very similar to the realy mod. Where you run a new heavy 12v to the device, and thats it. splice into the existing wires to the motor and have that be that. If i cant do it that way, im not intereted in doing it. I had originally thought it would be a fairly simple matter (and it still might be with one of the boosters mentioned above) but if its not, i'll just do the relay mod and live with whatever i get. Im going to order a booster tomorrow. and will report with my findings. Although it will be the end of the month before i get it since its coming from China! :doah:
 
Blue85 said:
Yeah, most of these motors have thermal protection device, but I don't remember seeing one in the motors I've opened for these trucks.
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This is the third one I've opened and all three have identical guts. If what's in the picture isn't to protect the motor from burning up from an overload then what would you say it's for? If I put a piece of cardboard between the contacts the motor doesn't operate so I'm assuming that's what it's for.


windowmotorendcap3b_zpsfc3893d7.jpg


windowmotorendcap1b_zpsd00f1f82.jpg



And just in case anyone is wondering what the inside of the motor looks like ...
adff0074-eaf9-4a2a-8dcb-b354fd8f44af_zps1ec2ef76.jpg
 
Yes sir, that's what it's for. I probably just forgot. If it's a dud motor, try soldering the contacts together and see how much faster it goes. I've cleaned and lubed these things, but never saw much improvement.
 
It's not a bad motor, just an extra one I got from someone on here. I was going to experiment with it by rewinding it with different size wire and # of turns to see what kind of improvement I could get but never got around to it.
 
I used a 12V battery on a 6 volt starter in my VW Beetle for a long time,never seemed to hurt it any..it started so fast it didn't run long enough to overheat it..
I see many small DC motors listed in catalogs rated for 12/24V,so I bet a window motor would last quite awhile on 24 volts provided its not under heavy prolonged loads or operated under a stall condition for long..
I suspect the factory wants the motors to be "weak" for safety reasons,so a kid wont get his head or fingers sheared off in a power window..

Power window and seat motors and very powerful--I have seen them used to lift plows on garden tractors and similar uses..one guy on a tractor forum used a 70 chevy truck wiper motor to power a hoist mechanism for a roto-till on his tractor that weighs 130 lbs..so far the nylon drive gear has lasted 2 seasons,he figured it would fail in short order!.
 
Why not just do a hopped up alternator? A lot of newer gm stuff charges at 15-15.5 volts and everything works great.
Another thing on the higher voltage,as voltage goes up the amperage needed by the load goes down so there is no danger of burning up wiring or connectors with higher voltage.
 
jake 03 said:
Another thing on the higher voltage,as voltage goes up the amperage needed by the load goes down so there is no danger of burning up wiring or connectors with higher voltage.
Click to expand...

Ohm's law: V=IR

Since the resistance will stay the same, if you increase the voltage by a percentage the current will increase the same percentage.
 
jake 03 said:
Why not just do a hopped up alternator? A lot of newer gm stuff charges at 15-15.5 volts and everything works great.
Another thing on the higher voltage,as voltage goes up the amperage needed by the load goes down so there is no danger of burning up wiring or connectors with higher voltage.
Click to expand...
This would be true if we were rewinding the motors to deliver the same power at a higher voltage. Of course we aren't and the whole point is to get more power. So current increases linearly (almost), but the power dissipated in the switches, wires and motors goes up exponentially (^2 of I). The reason it's not completely linear is that the motors create a higher voltage the faster they spin, known as "back EMF" (electromotive force). If you spin the motor fast enough, the current will actually approach zero, as the voltage of the motor gets close to the battery voltage. But the linear/exp relationship is pretty much true at the end of travel when the motor is stalled.
 
Well I just ordered the $8.70 voltage booster. Should be here in a couple weeks. At least then I can test the concept.
 
If you have an 18V cordless tool you could connect the battery pack up to the motor and test it now.
 
rampage said:
Something to consider - inside the motor casing is a thermal/overload switch. If the motor starts draws too much current then the contacts open and the motor doesn't operate until they cool down and make contact again. Bumping up the voltage by 20% will make the motor draw 20% more current. If you start having issues with the motor cutting out then you'll know why.
Click to expand...

And something else I thought of - make sure the stock wiring and fuses are able to handle the increased current when the motor is stalled.
 
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Ordered it. It showed up. I tried it. Worked as advertised but did not work to roll the windows up or down. Wouldn't handle enough power I guess.
 
What is the output current rating? If it's less than 15-20A, then it just can't handle the starting current. Also, what is the input voltage rating? I'm kind of curious how you hooked it up. It will need a lot of current, so it should be underhood or have a heavy wire run in for it. If you just installed it with the stock wiring in the door, it probably has 8V or less on the input (when you push the button) and can't operate. If you attached to the fuse block, it probably still needs an input rating of 9V or lower.
 
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