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How to get 12 volts from 18 volts

How would i regulate 18 volts(2 9v batteries) to put out 12 volts instead? im doing this because 2 6v batteries is really heavy(im replacing 2 6v batteries, and they are also broken... dont ask how) thanks

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ledzep567 (author) 9 years ago
WAIT couldnt i just use 8 AA batteries??????? thats 12v
ledzep567 (author) 9 years ago
ok well seeing as this isnt my device im risking the death of (and the fact that it cost like 200 hundred bucks) its (boiled down) a cassette player with a long cord going to a speaker and its purpose is to project sound a ways a way. so im guessing id be best off getting a 12v regulator from radioshack?
Brennn109 years ago
Radioshack has 12V regulators.
hows about a nice and simple voltage divider...

two resistors in series the middle take off is 12V

the ratio would be 12:6 so anything like

for sake of argument:

18V+---|600ohms|----------|1200ohms|
`````````````````````````````|
````````````````````````12V out

Ignore the " ` "s they're for formatting only...
LM7812, like NachoMahma said. Pins go input ground output.
Kiteman9 years ago
How?
Kiteman Kiteman9 years ago
(I reckon it was a bizarre macho-juggling accident)
NachoMahma9 years ago
. 7812?
ledzep567 (author)  NachoMahma9 years ago
wow, thats interesting... i was hoping just a resistor hahaha but il look into that. thanks
PKM ledzep5679 years ago
It also depends what you want it for- if you want it for a 12V light you could just use a resistor but you'd be wasting 1/3 of your power. If you want it for anything more complicated than a lightbulb you will probably have to use a voltage regulator like the ones Nacho linked you to.