Thread: Too many amps for a wiper motor?

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Please help!

I'm using a 1973 wiper motor, and my current power supply is a battery charger with 6 VDC at 6 amps. The motor runs at the speed I want, but it has trouble lifting my bride's head prop, and it gets stuck pretty easily. So now I'm looking into buying a new power supply with more amps.

The supplies I'm looking at are: 5V 8A, 5V 12A, and 5V 22A. Is it possible to have too many Amps? I'm worried about losing the motor and being stuck with a static prop.

I also just bought a DCM-249 wiper motor from All Electronics, which works great at 6VDC, but a little fast.

I want to buy a power supply for each motor, both in the 5-6 volt range, but I'm not certain what to do. Any advice would be greatly appreciated!

Michael

I don't know how good you are with wiring but You can use a PC power supply to power your props and you might have or know someone that has an old scrap PC you can pull the power supply out of.there is a 5V,12V and some in betteewn Voltage with these or you can buy them new online for about 20 bucks.the how to to make these work is online too.I forget who it is that has the how to hack for these but it is there I want to say scary terry?might be able to find it in the search here too.

Thanks, I have looked over Scary Terry's pages. They are very informative but there isn't much mention about amps. I think the computer power supply probably doesn't give out enough amps for my needs, and I really want to push the amps as high as I can reasonably and safely go, especially since I now know 6 amps won't cut it.

When it comes to power supplies you can never have too many amps, just too few, you cant overload a circuit because you have too many amps in the power supply, however, you can burn it out if your circuit draws too many amps from the power supply, so if you have an 6amp power supply just make sure that your wiring is rated to 6amps

automotive motors can draw a fair bit of power, and should not have a problem with 6amps

6 amps should be enough though. I'm not experienced with the older wiper motors though. I good place to pick up a higher amp PS is any HAM radio store, they usually have a good selection.

The older wiper motors normally use 12v right from the batt, they can handle & draw alot more amps than the new ones. Try hooking it up straight to a 12 v batt & see what your prop does,
I bet that you are not giving it enough amps to provide it the torque energy it needs to lift your prop head. I work with the older motors as we build older hot rods & muscle cars & usually have
plenty of these motors lying around for prop use.6v may be what you want speed of prop wise,but without those amps.............ain't gonna cut it.The older motors need
more amps than the newer ones now,(older models) use 8-10amps min,15 average draw with resistance applied (wiper arms with linkage, or prop pending weight of needing to be moved).

yeah, I've seen a 15amp draw from a loaded wiper motor before now, this is why computer PSUs are good, they can supply that kind of power without paying a lot of money for it.

Thank you so much for all your advice! Now I can go buy my power supply and cross my fingers! (I'll be posting my 'adventures' on my project page!)

I don't think amps are your problem - the Torque of the motor will drop as you lower the voltage into it. I've found that once you're under 8 volts, it will stall if the load is too heavy.

KevinS - I did read about that on a website discussing volts vs. amps, but I couldn't really comprehend how the relationship works to create varying amps in different power supplies with the same voltage. It seems to depend on resistance, and I just don't get it.

I've been trying to learn about electronics, but as soon as they stuck amps in there (in like the first chapter) it suddenly got hard for me to visualize it.

I think I'll go with 5V 8A for the All Electronics motor and 5V 12A for the 70's motor. The All Electronics motor lifts my prop with no problem, but it's just too fast, even at 6 volts. I suppose I could try making linkages to change the speed, but that's a whole other concept that I never know how to get my desired result! It is a lot of fun building this stuff though, but time is getting short!

Michael