Abnormality detection device for resistance bridge circuit

Abstract

Abstract PURPOSE:To detect exactly the abnormal state such as disconnection in a resistance bridge circuit, by executing the detection at intervals of a specified period in the program for discriminating overload which is normally executed to detect whether the potentials at a pair of arm junctions are within a prescribed permissible range or not. CONSTITUTION:The output terminal of an exciting power source 2 is connected between a pair of mutually opposed arm junctions 11 and 12 of a resistance bridge circuit 1, and a square wave signal is applied thereto in accordance with the latched output from a microprocessor 3. The (a), (b) contacts of a signal reception circuit 4 constituted of an analog switch are connected to a pair of the other arm junctions 13, 14 of the circuit 1, and are pulled up by a resistance 9. The output potential is taken into the circuit 4 by the command signal of the microprocessor 3 and is taken into the microprocessor 3 through an A/D converter 5. The decision of abnormality is accomplished at a specified interval in the program, and the abnormality is discriminated by the comparison of the permissible upper and lower limit values stored in a data ROM32.

Inventors

• 👤 Masamitsu Tada
• 👤 多田　正光
• 👤 Takakimi Yamamoto
• 👤 隆公 山本
• 👤 Nobuyoshi Kobayashi
• 👤 小林　宣誉

Bibliographic Details