2. Modulator construction technologies

2.1 Electromechanical part of an electropneumatic modulator

As previously mentioned, this part converts the electrical power of the control system into mechanical power for positioning the variable orifices of the pneumatic stage. In static equilibrium, this conversion implies a positioning accuracy compatible with the expected modulation performance, and in dynamic equilibrium, a speed compatible with the controlled process. Generally speaking, in accordance with the rules of control-command of continuous systems, the dynamics of the modulator must be negligible compared with the dynamics of the controlled system. In addition, the electrical input power must be minimized in relation to the controlled pneumatic power, to ensure correct efficiency of the entire electro-pneumatic system....