0
\$\begingroup\$

I am wanting to control the flow rate of a pressure regulator (https://www.festo.com/net/SupportPortal/Files/505126/VEAB_2018-05a_8080669g1.pdf). My idea is to control this with a PWM signal 0-5v.

The signal requirements for the PPR is either a voltage of 0-10v or current controlled 4-20ma.

Option 1: Now if you had a MCU with PWM could you use put a 125 ohm resistor to the input of the regulator if it was current controlled? As at 0.5v you have 4ma and at 5v you have 20ma.

Option 2: I could use a mosfet but I am unsure on what I a looking for if I want use one. I know the VGS(th) must be less than 5v to be used for a MCU but how do I know how much voltage will flow when the voltage at the gate is 1v or 5v?

I am open to what you guys think could be best and any help would be appreciated.

Cheers

\$\endgroup\$
0

1 Answer 1

Reset to default
0
\$\begingroup\$

I suppose that could work, it wouldn't be very accurate current control however. There are better ways.

A better circuit would be one like this which is for controlling current from 4mA to 20mA :

enter image description here Source: 4-20mA Output from Arduino

There are also other circuit in the question:

I've used variations of this one before many times:

enter image description here

\$\endgroup\$
1
  • \$\begingroup\$ Can you explain the circuit operation in circuit 2? \$\endgroup\$
    – Newbie
    May 12, 2019 at 1:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.