how to solve this problem 1

[richerdick]

I have a sensor that currently drives an counter. output fromn the sensor seitches from 2v when off to around 12v when on. I would like to feed the output from this sensor into another counter in a different location that has slightly different parameters. the problem comes that this counter likes to see 1v or less for an off signal so will not count as it does not see the sensor state change. the counter will see anything above 2v as an on signal.
the counter also requires an extra powersupply for the back light. my concerns/ideas are the following.
the ov return path for the sensor signal will come from a different powersupply to the slaved counter, there is no extra connection for this ov return path so i intend to tie both ovs to ground. the 0v for the sensor which has a 12v supply and the 0v for the added counter which has a separate 24v supply. will this be sufficient?
my second problem is the switching voltage levels. my initial thoughts were to try to use a diode to drop 0.6v across it to bring the signal within range, however i foud that this actually increased the voltage at the counter. my alternative is to split the signal voltage with a potential divider and feed the center tap into the counter this way the voltage will be halved but should be within the counters limits.

what do you think can you make any recomendations or do you think this will work
cheers

 

[VEBill]

"...use a diode to drop 0.6v across it to bring the signal within range, however i foud that this actually increased the voltage at the counter..."

Miracles never cease.

 

[VEBill]

Seriously now, use two wires including one return wire. If one diode doesn't work, try two in series. If the input to the counter is Hi-z, then add a resistor load in parallel.

Everything should fall into place.

 

[OperaHouse]

I'm thinking opto isolator. Assume your sensor is a three wire unit that can supply a couple ma to the led of an opto isolator through a suitable resistor. Then just use a suitable pull down resistor on the emitter of the photo transistor. Isolation and level change!

 

[richerdick]

i thinkl the resistor load in parallel was what was missing the counter input must have had a very high impeadance