Synchronous demodulator circuit

• Main Author: FOX; DAVID A
• Format: Patent
• Language: English
• Published: 22.04.1975
• Subjects: BASIC ELECTRONIC CIRCUITRY; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TOANOTHER; ELECTRICITY; GENERATION; SYSTEMS FOR STORING ELECTRIC ENERGY

A synchronous demodulator is provided for receiving signals including one that is subject to variation in waveform and a predetermined reference signal having a known waveform from which signals is produced a demodulated output representing the relationship between the first and second signals with respect to their phase and amplitude. The apparatus includes means such as a signal transformer with a center-tapped secondary to produce two phase displaced signals from the first signal which are then applied by means such as a gate controlled two-channel input amplifier to the input of an amplifier such as an operational amplifier from which the demodulated output is obtained. Application to reactive load division between parallel AC generators is advantageous.