| 摘要 |
<p>A modular switch device (20) includes a housing (22) enclosing an interconnected control module (70), a display module (72) and a power module (74). A sensor module (42) supplying analog data signals from one of a temperature (104) or pressure sensing element (170) connects to the control module (70) through a passage (48) in the housing. A user can select between AC and DC switched output modules (66) and the presence or absence of a 4-20 milliampere output module (62, 64) by plugging and unplugging same from wells (56, 58, 60) provided in the housing. The manufacturer and user thus can modify the standard housing, which includes an internal electrical assembly to be a pressure or temperature switch and to provide selected output switch characteristics by applying and removing selected sensor and output modules thereto. The control module (70) includes one analog to digital converter (134) and controls via microprocessor (136). The sensor module (42) includes an amplifier (120), a reference voltage circuit (122) and a non-volatile memory (124) containing calibration data.</p> |
