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Interface 12V down to 5V logic...

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adamey

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I want to take an input voltage that could be anywhere from 10V up to 15V and have it interface with 5V logic.

This is for automotive use, so depending on whether the car is running or not and what loads may be on the voltage in the vehicle could be 10V (engine cranking or low battery) to as high as 15V (alternator slightly overcharging).

How can I get this wide of a voltage range to work with 5V logic so that any voltage between 10-15V will give me a guaranteed "ON". Of course, off would be 0V.


I want to use this to monitor various switches in the vehicle to see if they are on or off (like ignition or accessories).
 

ericgibbs

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Most Helpful Member
I want to take an input voltage that could be anywhere from 10V up to 15V and have it interface with 5V logic.

This is for automotive use, so depending on whether the car is running or not and what loads may be on the voltage in the vehicle could be 10V (engine cranking or low battery) to as high as 15V (alternator slightly overcharging).

How can I get this wide of a voltage range to work with 5V logic so that any voltage between 10-15V will give me a guaranteed "ON". Of course, off would be 0V.


I want to use this to monitor various switches in the vehicle to see if they are on or off (like ignition or accessories).
hi,
Use a resistive divider and in parallel with lower resistor have a 4.7V zener diode.
 

crutschow

Well-Known Member
Most Helpful Member
Or you can simply use 78(L)05 voltage regulator.
I believe he's concerned about logic levels, not the power for the logic.
 

KMoffett

Well-Known Member
Or you can simply use 78(L)05 voltage regulator.
Never thought of using a regulator as a level shifter...but then...that's what it is. :D

Ken
 
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