Q-FACTOR CAPACITOR-BASED METER Russian patent published in 1997 - IPC

FIELD: electric engineering, radio engineering, in particular, testing instruments for bridge and resonant meters for frequencies of 0!1-100 MHz. SUBSTANCE: device has two serial circuits of capacitor and resistor and two current conductors to measuring unit, which has two variable capacitors and two-channel bias source, which is designed as reference voltage source which terminals are connected to two digital-to-analog converters which outputs are differential and have same polarity. In addition device has control unit which outputs are connected to control inputs of digital-to-analog converters. Each capacitor-resistor circuit is connected between one output of measuring unit terminal and differential output of one digital-to- analog converter. Variable capacitors are connected in series- opposing and inserted between common points of capacitors and resistors. Outputs of digital-to-analog converters of opposite polarity are joined and are connected to middle point of variable capacitors. EFFECT: increased resolution, minimal initial capacitance, increased speed. 4 dwg