SYNCHRONIZATION DETECTING CIRCUIT

• Main Author: KIDOGUCHI HIDETAKA
• Format: Patent
• Language: English
• Published: 17.10.1987
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; SYSTEMS FOR STORING ELECTRIC ENERGY; TESTING

PURPOSE:To detect the coincidence of two sets of AC power sources without being affected by a frequency change or change of circuit parts constant, etc. by outputting a logical H signal when an AC voltage is in a positive region and a logical L signal when said voltage is in a negative region. CONSTITUTION:The AC voltages outputted from a commercial power source 2 and an inverter 4 are respectively converted to the logical H signal in the positive voltage region and to the logical L signal in the negative voltage region by signal converters 30, 31. The output signals from the converters 30, 31 are subjected to the phase discrimination as to whether the voltage phase of one AC power source is advanced or delayed relative to the voltage phase of the other AC power source by D type FF32. The degree of the phase difference between the two power source voltages is detected by an exclusive OR element 33. The polarity of the input signal to an integrator 37 is changed over by the output signal of the FF32 and the integration time of the integrator 37 is changed over so as to meet the output signal of the element 33. The phase difference between the two AC power source voltages is detected from the quantity obtd. by holding 38 the peak value of the output from the integrator 37.