I'm in need of a level shifter from 15V to 5V.
We used to use 5V on our limit switches but after a while we started to have the switches fail, they were not cleaning themselves with any arcing.
We are now redesigning our controller and have an opportunity to fix this problem.
I have a Supply voltage of 15V that I wish to pull up the limit switches to but my uC is an Isolated 5V, I thought about using an optoisolator with a CD4050 to shift the level but I ran into a problem on powering the 4050, if I power it with my isolated 5V then I'm no longer isolated and I can't use the 15V then my outputs will be 15V and blow the Opto. I don't want to add another DC-DC just for this one device.
Can anything think of a simple solution to my problem?
Thanks
Ron