
Control Circuitry
Chapter Five: Theory of Operation
32
Control Circuitry
The controller employs the above measurement technique and utilizes a control circuit that
provides drive current for the proportioning control valve. The flow controller accepts a
0 to 5 VDC set point signal, compares it to its own flow signal, and generates an error voltage.
This error signal is then conditioned by a PID (Proportional-Integral-Derivative) algorithm and
amplified so that it can reposition the control valve, thus reducing the control error to zero.
Since the control valve is normally closed, the 1479 unit lifts the armature and plug assembly
from the seat to regulate the gas flow rate.
Содержание Mass-Flo 1479A
Страница 3: ...119474 P1 Rev B 10 97 MKS Type 1479A Mass Flo Controller ...
Страница 8: ...Table of Contents vi ...
Страница 10: ...List of Figures and Tables viii ...
Страница 34: ...Control Valve Chapter Three Overview 24 This page intentionally left blank ...
Страница 40: ...The Optional Input Chapter Four Operation 30 This page intentionally left blank ...
Страница 44: ...Zero Adjustment Chapter Six Maintenance 34 This page intentionally left blank ...
Страница 56: ...Physical Specifications Appendix A Product Specifications 46 This page intentionally left blank ...
Страница 70: ...Model Code Appendix D Model Code 60 This page intentionally left blank ...
Страница 72: ...Index 62 T Troubleshooting 35 U Unpacking 9 checklist 10 opening 9 V Valve override 28 Z Zero 26 ...