• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 47 subscribers
  • Views 1412 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Proportional Valve Driver

Michael Koch
Prodigy 10 points
Other Parts Discussed in Thread: XTR110, XTR111, XTR300

I would greatly appreciate advice regarding the use of a thermocouple & PID with a 4-20mA current output to control a 2-way Clippard proportional valve (EV-PM-20-6015).  The valve can use DC current or PWM for an open or closed-loop control system.  Since the PID can not supply enough current to drive the valve directly, what type of driver circuit would best amplify the output to accurately control the proportional valve.?.

The stats for each are as follows:

Proportional Valve

Vnom: 0-20 Vdc

Vmax: 24.8 Vdc

Iin: 0 - 0.092A

Rcoil: 218 ohms

P: 1.9-2.3 Wmax

PID controller

Power Supply: 90-240V ac/dc  50/60Hz

Consumption: <5VA

Accuracy: 0.3% F.S +/- 2digits

Sampling Cycle: <300ms

Input: TC/RTD

Output: 4-20mA DC output

Thanks,

Mike

  • 0
    TI__Guru 63985 points
    Hi Mike,

    So I understand the system better I'd like to confirm some things. First, it sounds like you'll be monitoring the temperature of something with a thermocouple and controlling the position of a valve with a 4-20mA signal to either maintain or adjust the temperature. You will use a PID controller between the thermocouple and valve to achieve the desired system response (overshoot, settling time, etc.)

    It also sounds like you already may have the thermocouple acquisition circuitry, and digital (or analog) PID loop figured out and the last part you need to design is a circuit that interfaces the PID output with a 4-20mA loop driver. Is that correct?

    If so, please send us a preliminary block diagram, circuit schematic, or simulation file that shows us what you have already. Based on what you have we'll see what we can come up with to interface with an XTR111, XTR110, or XTR300 3-wire current loop transmitter IC that can be used to drive the 4-20mA signal to the valve.