Sync. demodulator for AC instrument transducer - uses four quadrant divider to which modulated and unmodulated signals are applied

摘要

An a.c. voltage amplitude modulated by the measurement signal is applied to the demodulator first input as the signal voltage, and a non-modulated a.c. voltage collected from the supply voltage applied to the a.c. voltage tapping. is applied to its second input as the reference voltage. A d.c. voltage analogue to the measured signal appears at its outputs as a result of linear signal processing. A four-quadrant divider is used as the synchronous demodulator (10), to which the signal voltate (UA) from the first input (12) is applied as numerator, and the reference voltage (UC) from the second input (16) as denominator. The quadrant divider is connected with two multipliers (20, 26) and two amplifiers (22, 28).