PROBLEM TO BE SOLVED: To provide an abnormality detection circuit in which lack of detection of short circuit is reduced by a simple configuration.SOLUTION: An abnormality detection circuit includes: an amplifier 21 having an output end, an inverter input terminal and a non-inverted input terminal to be connected, respectively, with loads R0, R1, R2; and an abnormality detector 243 connected with the non-inverted input terminal, detecting the occurrence of a predetermined potential across the load R2 normally having a substantially same potential, and outputting a signal indicating occurrence of an abnormality. The load R2 connected with the non-inverted input terminal is a resistor for impedance matching, connected with the input terminal of an amplifier circuit and reducing the offset voltage of an operational amplifier OP1, and has a value of resistance of R1. The abnormality detector includes threshold setting sections TR1, R3, R4 for defining the potential difference to be detected.SELECTED DRAWING: Figure 5
【課題】簡易な構成で短絡の検知漏れを低減させる異常検知回路を提供する。【解決手段】異常検知回路は、出力端、反転入力端子、及び非反転入力端子にそれぞれ負荷R0、R1、R2が接続される増幅器21と、非反転入力端子に接続された、正常時はほぼ同電位である負荷R2の両端に所定の電位差が生じたことを検知し、異常が生じたことを示す信号を出力する異常検知部243とを備える。非反転入力端子に接続された負荷R2は、増幅回路の入力端子に接続された、オペアンプOP1のオフセット電圧を低減するインピーダンスマッチングのための抵抗器であり、抵抗値がR1に等しい。異常検知部は、検知する電位差を規定する閾値設定部TR1、R3、R4を含む。【選択図】図5
ABNORMALITY DETECTION CIRCUIT
異常検知回路
2017-01-12
Patent
Elektronische Ressource
Japanisch