Set-point signals 0-5 Vdc or 4-20mA are employed to control the output pulse width modulated voltage at a fixed frequency (≈30KHz) and amplitude. Incoming power to the valve coil is applied and discontinued for predetermined periods of time by a low loss solid state switching element. As incoming power is applied, energy in the inductive coils increases. When it is discontinued, energy stored in the coil maintains the magnetic flux level required to hold the flow at the controlled rate. This cycle takes place many thousands of times per second. The wide range of power input features conveniently accommodates 12-32 Vdc sources. The Auto-Select feature of the Driver Module recognizes the type of reference signal received and defaults to 0-5 Vdc if both signals are provided. A complete Flow Regulating System includes a PSV Electromagnetic Valve connected to a Pulse Width Modulated PSV-D Driver Module. Optional RS-232 or RS-485 modules are available.
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