Newbie Amperage question

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Armed101

New Member

• May 19, 2011

• #1

Hi All,
I am doing a project involving a car battery and my device that is hooked up to the battery requires the ranges of 10 to 15 volts and an amperage of 1.9 to 2.2 amps. So do i need to reduce the amperage to something within that range or does the device only use what it needs to operate?

 

Last edited: May 19, 2011

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carbonzit

Active Member

• May 19, 2011

• #2

It would help us immensely to know exactly what kind of device you want to connect. Some (like motors) don't require current (what you call "amperage") limiting, while others (like LEDs) do.

 

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Armed101

New Member

• May 19, 2011

• #3

I am running a dc ballast for one 48" florescent light bulb.

 

audioguru

Well-Known Member

Most Helpful Member

• May 19, 2011

• #4

A car battery supplies up to 800A to the starter motor in winter.
The clock in a car is connected directly to the battery and it doesn't draw 800A. It draws 0.0001A because that is all it needs.

What do you have that draws more than 2.2A? Will it work properly when you limit its current to 2.2A?

Edit: A single 48" fluorescent tube draws 34W to 40W. The ballast circuit heats with about 5W.
Then if the battery is 15V the current is 45W/15V= 3A. It might draw more current if the circuit is crushed in an accident but then the fuse will blow.

 

Last edited: May 19, 2011

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carbonzit

Active Member

• May 19, 2011

• #5

By "DC ballast" I ASS-U-ME you mean an electronic ballast for fluorescent lights, right? You don't need to worry about limiting the current; it'll only use what it needs.

And if it's happy with 10 to 15 volts, all you gotta do is connect the thing up to your car's electrical system and you're done.

 

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Armed101

New Member

• May 19, 2011

• #6

Yea the company that sold me the ballast says that i have to stay within that range. Because the ballast will overheat, also they said that it could mess up the flourescent bulb making it not last as long. I hooked up a AC to DC power supply to see if it would work. and it works ok with 12volts 1 amp and i also tried it on a 14 volt 1 amp and the light seemed brighter.

 

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Armed101

New Member

• May 19, 2011

• #7

Well ill go ahead connect her up and see if she works. Ill let you know in a few seconds.

 

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Armed101

New Member

• May 19, 2011

• #8

Well just hooked it up and awesome it works!!!!!!!! Thank you all. I really appreciate it!

 

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carbonzit

Active Member

• May 19, 2011

• #9

Great! I always love it when I can help someone by doing practically nothing ...