Precision Voltage & Current Sources (Applications)
Output source and readout for positioning HVAC motorized valves
Field tested @ Crane Fluid Control Laboratory and on field service
Developed for a well known valve manufacturer for positional control of 24 Volt AC motor driven valve actuators with a 0 to 10 Volt control input. Output switched in 1 Volt steps the position of the valve can be controlled to 0.1% of position. Unit provides 24 Volt AC power source for motors and precision 10 Volt DC reference circuit attenuated down into 1 Volt steps to drive an output power stage to valve input control electronics. Output stage provides negative feedback to adjust for IR losses at output. Output is short circuit and overload protected on control output by current limiter. Supply is nominal UK 230V AC mains supplied, 110 Volt site versions available. Feedback and voltage readout accurate to 0.1% gives position to “go”and position “at” readout to see command and actual position, (test for jammed or seized valve).
Suitable for Crane, Danfoss and many other actuator control valves.
For further information on this and other special projects we have been involved with contact David Baxter.