Hi I have a classic motorcycle and I have updated the old alternator to a Permanent Magnet Alternator, but the motorcycle has a starter safety relay ( which basically stops the starter motor from reengaging once the engine has started) which is activated by 4 volts from the old style alternator now i need something small rugged and vibration proof to step down the voltage from 12 volt to 4 volt any ideas Jamie
converting 12 volts to 4 volts
May 29, 2008
7 Replies
See the following which is for 12V to 3V
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I guess you have to find a zener diode that is about 4.7V and of course you should recalculate R1. Look @
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See the following which is for 12V to 3V
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I guess you have to find a zener diode that is about 4.7V and of course you should recalculate R1. Look @
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How much current does the relay need to be energized?
JF
A resister? Need to know the coil resistance of the relay for proper calculations
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ns
hello friend You can use voltage regulator LM7805 (NATIONAL Semiconductor/ FIRCHILD) , so the output of the regulator will be 5Volts @ 500mA max. Then you can connect a diode or a resistor with a filter capacitor to drop further by 1Volt. Good Luck.
REGARDS SUBIR KUMAR MANDAL SCIENTIST 'B' DRDO
ns
YOU can also try LM317, adjustable voltage regulator, Aand to drive a relay you need 10mA to 20mA depending upon their types.
There are many, many relays which require more than 20mA of coil
drive.
JF
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