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resitor? Answered

What resisitor do i need to go from 18Volts to 1Volt?

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steveastrouk
steveastrouk

Best Answer 11 years ago

What are you trying to achieve  ? A resistor may not be the best way, and besides, you need to know the current it will pass.

Steve

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jeff-o
jeff-o

11 years ago

Maybe this voltage divider calculator will be helpful.  But be aware, it's not that precise, and it's only for relatively low-current loads.  If you draw too much current (say, more than 5mA) then you will no longer get 1V out.

If you want a steady, regulated 1V then you'll need a voltage regulator.

If all you want to do is light an LED or something, give us a few more details and we'll try to help you out.

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michoi
michoi

Answer 11 years ago

i want to take 18 volts from 2 nine volts then put it through an led

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jeff-o
jeff-o

Answer 11 years ago

Oh!  In that case you'll need a single resistor, between 820 ohms and 1000 ohms, with a 1 watt rating.

Any reason why you're using two 9V batteries for a single LED?  It's very much overkill.  You're cooking off a great deal of power through the resistor so the batteries won't really last very long.

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michoi
michoi

Answer 11 years ago

after the led im gona have a 30 volt cap and a speker

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jeff-o
jeff-o

Answer 11 years ago

OK....   So what is it you're trying to build?

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michoi
michoi

Answer 11 years ago

amplifier

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jeff-o
jeff-o

Answer 11 years ago

Okay, so what are you using for your amplifier, a transistor, an LM386, or something else?

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michoi
michoi

Answer 11 years ago

transistor, not sure what kind it is

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jeff-o
jeff-o

Answer 11 years ago

Do you have a schematic you're working from?  I need more information!

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NoFiller
NoFiller

11 years ago

As steveastrouk said, more information is needed. Maybe you could describe in as much detail as possible the project you are working on and what you are trying to do. That will at least let us know what further questions to ask you.