24V compatible input -> 5V microcontroller

[jabidof]

24v as input for micro controller

Hello there,

I'm looking for a simple way to have an input to a device that is 24V compatible (truck voltage level). The idea is to have the "ignition contact" signal being inputed to a microcontroller unit. "Ignition contact" is 24V but microcontroller unit inputs are 5V.

I though of using a power MOSFET that has a Vgs of > 24V.

Anybody got some experience on that topic?

Thanks

 

[IanP]

24v interface microcontroller

The safest way is to use an optoisolator - see attached picture, but in most cases a simple clamping circuit consisting of a (1-10kΩ) series resistor and 4.7-5.1V Zener diode (across the input and GND) should work well ..
For more details goto:
https://www.cq.cx/interface.pl

Rgds,
IanP

 

[jabidof]

microcontroller 5v to 24v

Thanks for your input. Appreciated the help.