Denford Software & Machines

I am curious and my inner Scrooge would like to use the old two wire proximity switches but the attached electronics is long since gone.

However I am only familiar with DC 3 wire versions which would be an easy replacement for me to deal with.

I am thinking that they were likely driven with 24V AC probably from the nice little isolating transformer.

I would like to take the output signal to an opto isolator and read a DC output.

Can someone tell me how they used to be used from an electrical&electronic perspective?

I was wondering if it would be as simple as using a rectifying diode bridge?

Any advice welcome,

Thanks,

Jon