Signal Conditioner

I would like to control a hydraulic distribution valve with the output of a 90-30. I was thinking of using the IC693ALG392 configured for -10 +10. The distribution valve basically consists of a 58 ohm coil that moves the pilot valve plunger. It is rated at 125ma. My question: is there a signal conditioner or something that would accept the signal from the analog output and have the horsepower to drive our coil? At this point, I would rather not redesign a distribution valve that is working great I would rather just replace the controller. Thanks in advance

Not quite sure what you are trying to control but maybe this is what you are looking for:

http://www.pwmcontrols.com/

It will take control voltage or current signal and drive a proportional valve coil. It is just simple open loop control of the valve unless you close a feedback loop at a higher level...

<I have no affiliation with PWM Controls>

Thanks ndzied1, Since this coil just moves a plunger up and down, I need something that will swap polarity. Zero volts (or something close to that is in the neutral zone whereby the valve is neither opening or closing. +10 volts (or more likely 7.5 volts) causes the valve to open at the maximim rate and the -10 (-7.5) causes the valve to close at the maximim rate.

#1: Some information about the valve will be helpful. Most valve manufacturers provide a driver card, but often driver cards from brand A can be used on brand B. I spent the day today working with valves very similar to what you describe.

#2: Depending on what you are trying to do here, the PLC may not be suitable, so some application information might be helpful. There are many hydraulic position control applications that are beyond the ability of most PLCs to do well - its a simple fact and if your application is one of these then just accepting that fact will be the first step in making your life much easier. You might need something like the Delta RMC70 - they are in your part of the country anyways. If we have information we can help.

The distribution valve and control valve was made by Fuji and is a turbine blade controller for one of our hydro plants.
The convertor coil is mounted inside the dark grey colored device
located on the top right of the distribution valve. Basically, it just moves the lever up or down to change the blade angle.
As you can see by the terminal board, there are only two wires going to this device to control it. I know what you are saying that some things cannot be controlled with a PLC and this may be one of them, but if there is not a signal conditioner available to do what I need then I will likely get a proportional valve (4-20ma) to do the job. I have done that in another plant with a 90-30 and it performs very well. I was just hoping to minimize the expense and effort by not having to get a proportional valve or something like that. Thanks again!

I've never used Fuji valves so I don't know anything about their product line. For a valve amplifier I usually use Rexroth cards or Atos cards, and have used Dennison cards. You might check some of these amplifier cards on the Rexroth web site for one that matches the valve specs, but I imagine that if Fuji makes the valve they also make an amplifier card.

Thanks for the help. I just got off the horn with American Governor http://www.americangovernor.com/driver_amp.shtml
They have an amplifier board they developed for EHI conversions.
They think they have one that will work for us. Thanks Again!

It sounds like your problem is solved but I wanted to throw this out. I've used a relay in the past to reverse the polarity of the DC out when I needed both the + and - output and only had the + source (0-10+VDC). If memory serve me correct we had a proportional joystick that gave 0-10VDC out. It had a limit switch to tell when off center up or down. I used the signal indicating down which energized the relay and reversed the polarity to the valve for 0-10-VDC)