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Cedar Rapids, Iowa | A solenoid should be able to take up to 100% duty cycle, which is exactly the same as a solid 12 volts (or whatever voltage the solenoid is rated at). I'd throw 12v at it and see if they move. You should be able to do that without any hydraulic power and still hear the spool moving inside the valve.
Typically with a PWM hydraulic valve you want a frequency of like 100-200 Hz. It's fast enough to be pretty smooth, but slow enough that the spool is actually moving a tiny bit between pulses. This overcomes any 'sticktion' where the spool would get sticky and not want to respond to small changes in duty cycle. I have done PWM at 1000 Hz, and it worked, but learned that its better to run in that 100-200 Hz range. The 33Hz you say they recommend seems low to me, but I suppose that would work too.
Also note that a PWM hydraulic valve will have a deadband. In my experience it usually takes 20-40% of the max voltage to get anything to start moving. | |
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Controlling a pwm hyd.valve
