ELECTRONIC CONTROLLER FOR A MODULATING VALVE

摘要

A valve control circuit (44) is disclosed for operating a modulating valve (10) which can be operated between a completely open and a completely closed position. The modulating valve control circuit includes a microcontroller (72) which receives an input signal from an external temperature controller. The microcontroller monitors and controls the position of the modulating valve by first determining the number of rotations of the bi-directional driving motor (16) required to move the valve from a completely open to a completely closed position. After determining the number of rotations for a complete valve stroke, the microcontroller positions the valve stem in the correct position according to the input setpoint as compared to an input range. The microcontroller positions the valve stem in direct relation to the proportion of the input setpoint signal with respect to the range desired. The modulating valve control circuit also includes a solenoid control circuit which can be operated to engage and disengage a solenoid clutch (36), such that the valve can include a return spring.