PROBLEM TO BE SOLVED: To solve the problem that, when utilizing a +5 V power source on the personal computer side by connecting a route measuring apparatus using an analog circuit to the personal computer through a USB interface or the like, a measured value of a measuring circuit becomes unstable and inaccurate by a power source noise which is specific to switching/regulator.SOLUTION: While a USB interface or a +5 V power source acquisition circuit uses a known earth separation circuit, supply in the apparatus of a +5 V power source on the personal computer side is suspended only for a moment when a measuring circuit measures an application current by applying a pulse voltage, and operation is continued during the suspension time only by accumulated power in a smoothing capacitor, to thereby remove noise contamination.COPYRIGHT: (C)2015,JPO&INPIT【課題】アナログ回路を用いた経絡測定装置をUSBインタフェース等でパソコン接続して、パソコン側の+5V電源を利用する場合、スイッチング・レギュレータ特有の電源ノイズにより、測定回路の測定値が不安定・不正確になっていた。【解決手段】USBインタフェースや+5V電源取込み回路は既知のアース分離回路を用いる一方、測定回路がパルス電圧を印加して通電電流を測定する一瞬間だけ、パソコン側+5V電源の装置内供給を停止して、その停止中平滑コンデンサーの蓄積電力だけで動作させ、ノイズ混入をなくした。【選択図】図2
