EDDY-CURRENT FLAW DETECTOR Russian patent published in 1998 - IPC

FIELD: nondestructive testing, detection of flaws in electric articles and on surfaces of articles of complex shape. SUBSTANCE: eddy-current flaw detector has controlled self-excited oscillator which oscillatory circuit includes N branches each incorporating eddy-current converter, blocking capacitor and varicap connected in series. Detector also has amplitude detector, threshold unit, indicator, frequency detector and pulse generator, controlled key, pulse counter and digital-to-analog converter connected in series and controlling processor. Common point of capacitor and varicap of each branch is connected to proper N-th output controlling varicaps. Controlling output of control unit is connected to controlling input of controlled key. Zero setting output of pulse counter of control unit is connected to zero setting input of pulse counter. Controlling outputs of indicator are connected to inputs of indicator. Logic input of control unit is connected to output of threshold unit. Pulse counting input of control unit is linked to output of controlled key and frequency measurement input of control unit is connected to output of self- excited oscillator. EFFECT: increased productivity of testing. 1 dwg