Group: DynoMotion	Message: 11261	From: develo_jon	Date: 3/25/2015
Subject: Two wire AC inductive proximity sensors

I am familiar with DC 3 Wire inductive proximity sensors but have some very old 2 wire AC ones in an old lathe, my inner over curious scrooge would like to wire the ones that are in situ up.

I think they were run from a 24V isolating transformer.

I was wondering about using rectifying diode bridge to create a DC output, wondering what Tom and others might think, other than I am a bit mean ? :)

Jon

Group: DynoMotion	Message: 11263	From: Tom Kerekes	Date: 3/25/2015
Subject: Re: Two wire AC inductive proximity sensors

Hi Jon,

Without any specs it is difficult to say what would work. I would try an experiment with something like an isolated 24V transformer connected to the sensor and maybe a 1K ohm load. Then check with an AC voltmeter across the resistor to see what happens. If the voltage changes from near zero to near 24V then it could probably be made to work. A single diode into a Capacitor would probably be sufficient to create a 24V DC signal. You might also want a bleed resistor to discharge the capacitor quickly (over a few 60Hz cycles) when the signal goes away.

Good luck

Regards

Group: DynoMotion	Message: 11264	From: develo_jon	Date: 3/25/2015
Subject: Re: Two wire AC inductive proximity sensors

Thanks Tom thats exactly where I was going with it.