Electronics question: auto inside the home

[wackychimp]

[Semi-prop related... actually prop ROOM related.]

Electronics experts, is it possible to run auto parts off of your home's power? Specifically, I want to run a power window motor and assembly inside my house. Power window stuff I've found says it runs on 12V. That's about all I know.

If it is possible, how? Been digging on Google & am not finding anything, but I may not know where to look & what questions to ask. I've done wiring, just not electrical wiring. What do I need to research? Power converters? Power conditioners? Something else?

Any help?

 

[hyperdyne]

You can do this, you just need the right equipment. What you will need is an AC-to-DC converter, commonly referred to as the "wall wart". You know, all those bulky black transformer type plugs you have for your cordless home phone, cell phone charger, laptop, etc.

You will need one that converts 110 VAC to 12 VDC. The available current you need will have to be determined, as all the adapters have a current limit they can source. For a motor, you might want something around 5A or so. You will have to determine that from its specs, what kind of load on the motor, etc.

I would suggest you look for "12V DC power supply" or "12V AC to DC adapter".

As an example, here is one I just picked up for a custom project that requires about 3A max - it works great so far!
http://www.allelectronics.com/cgi-bin/item/PS-1233/480/12VDC_3.33A_SWITCHING_POWER_SUPPLY_.html

 

[motman241]

Yes, what Hyperdyne said. I know the Shack used to carry heavy duty power supplies (bigger than the wallwarts). It was specifically meant for car stuff, and was about 9"X6"X4". They came in 3 amp and 10 amp (I think), and had cigarette lighter plugs and banana jacks/binding posts.

Radio Shack has changed in the last year or two, so I don't know if they would still carry these or not.

 

[jackdoud]

You're gonna pay a premium buying an new wall wart at Radio Shack. I'd highly suggest checking out local yard sales/tag sales/garage sales whatever they call them in your area. People usually have a couple where the appliance they go to has broken and you can get them cheap. Just check the plug box for the output specifications to make sure it does 12 volts at atleast the minimum current you need. Often you can find power jacks at radio shack that the cord will plug into keeping you from having to splice on a new plug.

 

[wackychimp]

This is great info. Thanks!

Ok so regarding amps, is this something that I need to have exact? Like for example your 5A example, could I just get one that puts out 10A & be ok? Or is that gonna fry something that needs only 5A?

ALso, just found this:

http://www.trcelectronics.com/Phihong/psc60w-120.shtml

Am I in right neighborhood?

 

[hyperdyne]

This is great info. Thanks!

Ok so regarding amps, is this something that I need to have exact? Like for example your 5A example, could I just get one that puts out 10A & be ok? Or is that gonna fry something that needs only 5A?

No, you wont fry anything. You just need a power supply that can source more than what you need. So if you have a device that needs 1A to run, you can use a power supply that can source 1A, 10A, 100A, etc. The device will just use whatever current it needs (up to 1A), and the power suppply will be able to deliver it.

If you used a power supply that could only source 0.5A in this case, your device would probably start behaving badly since the power supply would be attempting to supply more current than it was designed to. And the power supply would probably shut down, burn up, etc.

Motors can have large stall currents, so that is why I mentioned you might need a power supply with a good amount of current capability.

They do have those 13.8VDC/15A power supply boxes at Radio Shack. They are good if you are running motors and other high current devices. I have used them before and they will run several motors no problem. Otherwise you can get away with a switching DC power supply like one I listed (or one used by a laptop). You can usually get those in 5-10A flavors.

 

[motman241]

Ok so regarding amps, is this something that I need to have exact?

No, you will not fry anything, as long as the power supply is AT LEAST what you need, or more.

The motor is meant for a car, so it runs on 12 volts DC. No problems there. Now, if it needs 2amps to run (just an example), you need to feed it with 2amps or more.

This is what I was thinking of, but like was mentioned, Radio Shack tends to be expensive. There's plenty of cheaper places online.

http://www.radioshack.com/product/i...ower+supply&kwCatId=2032056&parentPage=search

 

[dalum]

What's the application going to be? Window motors are brutal on current draws, especially if you don't switch them off with a limit switch fast enough after travel is gone. Roll a couple windows up in your car at the same time and watch your headlights. They will be bright till your windows hit the top and if you don't let go of the switch they will start to dim. You could possibly spend several hundred dollars getting an AC power supply robust enough to power them properly. Another alternative to consider is a sealed deep cycle car battery (or several in parallel) and a charger for that battery(s). That will give you the peak current outputs needed and should be cheaper overall.

ETA if you have the motor and a car battery you can put an amp meter in series with the motor to measure its current draw. Then you can use that number to size up an ac-dc converter if you want to go that route.

 

[Gigatron]

This is great info. Thanks!

Ok so regarding amps, is this something that I need to have exact? Like for example your 5A example, could I just get one that puts out 10A & be ok? Or is that gonna fry something that needs only 5A?

ALso, just found this:

http://www.trcelectronics.com/Phihong/psc60w-120.shtml

Am I in right neighborhood?

That should do you just fine. You'll just need to cut off the power lead and seperate the pos and neg so you can attach them to the power leads of the motor.

TRC has a lot of great stuff. When I was looking to build a spray booth, I had a whole list of stuff that I was going to get from them.

-Fred