DETECTION CIRCUIT FOR DETECTING RESISTANCE VALUE IN PRESCRIBED RANGE

摘要

PROBLEM TO BE SOLVED: To provide a detection circuit for detecting the resistance value of some substance simply in a short time regarding whether the resistance value is within a prescribed range.SOLUTION: A circuit 1 for detecting a resistance value within a prescribed range includes: a first integration circuit comprising the series connection of a resistor of a substance to be detected and a first capacitor when the substance to be detected exists between a first terminal and a second terminal; a second integration circuit comprising the series connection of a second resistor and a second capacitor; a third integration circuit comprising the series connection of a third resistor and a third capacitor; a power supply for supplying a DC voltage to the first to third integration circuits; a switch for supplying the DC voltage from the power supply to the first to third integration circuits; and a determination circuit for outputting a signal indicating that the resistance value of the substance to be detected is within a prescribed range when the output voltage of the first integration circuit becomes a prescribed voltage from when the output voltage of the second integration circuit becomes a prescribed voltage till when the output voltage of the third integration circuit becomes a prescribed voltage after the switch is placed into an electrical continuity state.SELECTED DRAWING: Figure 1