motorized 3 way valve

[mo_eng]

hi all
i have a 3 way motorized valve with their actuator . and i want conttrol that with room tempreture.
so can i control that without use a plc.?
i choose an actuator with analoge input 2- 10v and a tempreture sensor with analog output 2- 10v.
i want to conect actuator and sensor in direct way without plc. can i do that?
this is so urgent help me plz
thank you for your notice

 

[danw]

If you connect your temperature signal directly to the valve, then a low temperature will drive the valve to one position, and increasing the temperature will proportionally change the valve position to the other extreme position, either mixing or diverting the flow, depending on how the valve is plumbed.

The chance of maintaining the desired temperature is about the same odds as winning the lottery. Yes, it could happen, but it's very unlikely.

The way this is done commercially is to put a PID controller between the temperature sensor and the valve and when correctly tuned, the PID controller adjusts its output to drive the valve to a position that will correct any difference between what you want (setpoint) and what you get (temperature). A single loop PID controller can do this, just like PLCs with PID capability can do this.

Dan

 

[TConnolly]

Is this a mix valve for heating a room? Skip the electric automation, use a vapor bulb operated valve - set and forget.