초록 ▼

A current-to-pressure (I/P) converter provides an output pressure as a function of the magnitude of a variable input DC current. The I/P converter includes a pressure sensor which produces a feedback signal representative of the output pressure. Based upon the feedback signal and the magnitude of th

A current-to-pressure (I/P) converter provides an output pressure as a function of the magnitude of a variable input DC current. The I/P converter includes a pressure sensor which produces a feedback signal representative of the output pressure. Based upon the feedback signal and the magnitude of the input DC current, an electrical control signal is produced which controls a device for varying the output pressure. The I/P converter also includes a circuit for generating a time-varying signal which is sent back over the current loop wires through which the input DC current flows. The time-varying signal provides an indication of whether the I/P converter is functioning properly. This permits diagnosis of possible causes of control system malfunctions without having to inspect the I/P converter itself.

대표청구항 ▼

A current-to-pressure converter for providing an output pressure as a function of magnitude of a variable input DC current, the converter comprising: means for connecting the converter to a circuit through which the input DC current flows; means for providing a feedback signal representative of the

A current-to-pressure converter for providing an output pressure as a function of magnitude of a variable input DC current, the converter comprising: means for connecting the converter to a circuit through which the input DC current flows; means for providing a feedback signal representative of the output pressure; means for providing a control signal as a function of the magnitude of the input DC current and the feedback signal; means for providing the output pressure as a function of the control signal; and means for transmitting, over the circuit through which the input DC current flows, a time varying signal having a characteristic which indicates whether the converter is functioning properly.