Running a 6V DC device on 12V system?

[TheThom]

Hello,

This is peripherally related to camping. My son currently requires a white noise machine to help him sleep. He is a light sleeper and the local state park campgrounds can get pretty noisy. I bought a battery powered one to use while camping, but it has a 15 min shut-off timer. It was a really. long. night.

I looked on the bottom of his wall plug in machine and it says that it's 6V DC. Since it's DC, Can I put a new plug on it and run on the battery system? Do I need to wire in a voltage reducer?

Clearly I'm NOT an electrical expert.

Thanks for your help.

Thom

[Nobody]

Pretty sure you can reduce the 12vdc to 6vdc by using a resistor in the circuit. Betcha you can check with your local Radio Shack (or other electronics store) for correct size/type resistor to do the job. Just remember that the extra 6vdc will be dissipated as heat so the resistor shouldn't be enclosed in a small container or covered by flammable materials. Another way to reduce dc voltage is by using a pulse width modulator in the circuit. Not sure if it's more expensive/complicated but I've seen folks do that to slow down a Fantastic Fan. I think it eliminates/reduces the heat dissipation problem...

Oops, just noticed you're apparently currently using 110/115vac to power the unit. You can purchase dc voltage power supplies that provide the exact voltage needed for the appliance.

I don't think a 6vdc appliance would last very long using 12vdc power...

[GerryS]

A step down transformer might make more sense. For 110 the sell those about everywhere, for 12v radio shaft used to. I'm sure they still do. Although lately that place has turned into a phone shop

[GuitarPhotog]

A step down transformer might make more sense. For 110 the sell those about everywhere, for 12v radio shaft used to. I'm sure they still do. Although lately that place has turned into a phone shop

Except that transformers won't work on DC. You might find a voltage reducer to allow you to use 6 VDC devices on 12 VDC but you are more likely to have to make one yourself.

If you know nothing about electricity, find someone who does to help you make a voltage reducer from some resistors.

<Chas>

[eamarquardt]

If you have 120 volt a/c available a "wall wart" power supply will work. It might be difficult to get one with the right connector that will fit your white noise machine.

A resistor is not a good solution as it will must be the proper resistance so the voltage drops to 6 volts and wattage or it will get too hot.

A better solution is a three terminal regulator if your device draws less than one amp. Less than a buck and easy to hook up.

http://www.circuitspecialists.com/6v-reg-neg.html

Here is a diagram on how to hook it up. If you are using 12 volts dc as an input, I doubt that you need the capacitors. So, you just need to hook up the input (12 volts dc), the ground, and the output terminal. If the regulator gets warm just mount it to a piece of aluminum.

http://www.onsemi.com/pub_link/Collateral/MC7900-D.PDF

Another option is to call the folks that make the device and see if they offer a d/c adapter.

Hope this helps.

Cheers,

Gus

[Greg M]

Head to your local Radio Shack. They'll have a cigarette lighter adapter that'll do the trick. Bring the white noise generator with you to be sure that you find the right tip.

-Greg

[pmowers]

You need something like this,
http://www.walmart.com/ip/Schumacher-Universal-12V-DC-to-DC-Converter/16550314
You can find them in most truckstops also, as well as many auto parts stores. Just watch the current requirements.

If you are running 110V, then you should be able to find something similar, they look like a wall-wart with a switch to set the output voltage.

[kludge]

Something like this would be an easy solution...

http://www.walmart.com/ip/Sabrent-AC-12 ... r/15819352

It takes 12V DC and turns it into AC. Then you just plug in the wall wart that you use at home.

[absolutsnwbrdr]

Something like this would be an easy solution...

http://www.walmart.com/ip/Sabrent-AC-12 ... r/15819352

It takes 12V DC and turns it into AC. Then you just plug in the wall wart that you use at home.

DC to AC to DC is horribly inefficient.

You need something like this,
http://www.walmart.com/ip/Schumacher-Universal-12V-DC-to-DC-Converter/16550314
You can find them in most truckstops also, as well as many auto parts stores. Just watch the current requirements.

This is what the OP is looking for.

[kludge]

I was going by easy over efficient since the OP said he was "clearly NOT an electrical expert."

If you go the DC to DC converter route you have to worry about getting the right connector on whatever device you purchase, and if it doesn't have the right connector included, then you have find one and swap it out and make sure you get the polarity correct. If that is within the skill level of the OP then that would clearly be the best option.

[Forrest747]

USB power output is 5 volts. might seeing if it will work off five volts and just put a usb connection on it.

[TheThom]

Thanks for the replies, everybody. I looked at the device more closely. I didn't think it had a removable AC cord initially, but it turns out that it does. So now it's just a matter of going to Radio Shack and finding a 12V cord (i.e. cigarette lighter adapter) that meets the size and specification requirements.

Had I realized the cord was removable, I wouldn't have asked how to re-wire it. At least I proved my electrician non-prowess

[BrwBier]

I dont know about now but back when I was a kid working at a gas station people wanted to put 12v starters and bulbs in there cars. In order to not change all the electrical parts they would put in a 12v battery for the starter and lights and run a screw down through the middle of the tar top and tap 6v for the gauges.
Brwbier

[GuitarPhotog]

I dont know about now but back when I was a kid working at a gas station people wanted to put 12v starters and bulbs in there cars. In order to not change all the electrical parts they would put in a 12v battery for the starter and lights and run a screw down through the middle of the tar top and tap 6v for the gauges.
Brwbier

It's been a long time since you could do that

<Chas>

[Nobody]

I dont know about now but back when I was a kid working at a gas station people wanted to put 12v starters and bulbs in there cars. In order to not change all the electrical parts they would put in a 12v battery for the starter and lights and run a screw down through the middle of the tar top and tap 6v for the gauges.
Brwbier

Yer showing your (our ) age Brwbier.