I do not think the the analog output can supply the power to hydraulic valve that the amplifier can.
james
I doubt it too.
Most hydraulic amplifiers use PWM to move the spool.
I was assuming JRoss's intentions were to use a PWM signal to an SSR that would control the current to the valve.
The output from the PLC would not be analog.
However, I think there are two problems with the SSR.
1. I doubt it could switch on and off fast enough
2. The SSR could only control positive or negative current.
Small DC motors use an H-bridge.
https://en.wikipedia.org/wiki/H_bridge
There are H-Bridge chips.
This would allow positive and negative current.
Bosch uses a spring to force the spool to one side to a safety position. I think the solenoid only need a positive current to force the spool to the neutral position.
This is safe and simple but I have always wondered if the response is the same shifting the spool in both directions. So far I have not anything to indicate the response is not the same.
We need to find out what kind of valve is going to be used. Provide a link to the pdf.