JPS62134567A - Apparatus for discriminating frequency of power source - Google Patents

Abstract

PURPOSE:To make it possible to certainly discriminate the frequency of a power source, by measuring the frequency corresponding to two times of pulse inputs given by the double frequency of the frequency of the power source. CONSTITUTION:A period (a)+(b), that is, period (c) or (d) is measured ant it is compared whether said period is received in a 50Hz data range or a 60Hz data range to discriminate power source frequencies (50/60Hz). In this case, the period (c) or (d) becomes constant regardless of the difference between the characteristics of photocouplers 2, 3. Further, when the discrimination results (50/60Hz) continuously coincid N times, for the first, time, it is determined whether the frequency of the power source is 50Hz or 60Hz. Therefore, erroneous discrimination of power source frequency due to external force is prevented. On the basis of said discrimination results, the counting of a base timer is performed by pulse input of 100Hz or 120Hz thereafter and the same control is performed regardless of the difference of power source frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention creates a frequency double from a commercial power source with two different frequencies, and uses the double frequency as the base t of various hummers.
Control power frequency Tl used as li time! ．． 'I'I
This relates to an I-separate device.

BACKGROUND OF THE INVENTION FIG. 2 shows an embodiment of a circuit that converts the power supply frequency and generates pulses of double frequency. Frequency doubler conversion circuit 1 includes a resistor, an impark gate, and a photocuff.

2. It is composed of a photocoupler 3, which reduces the pressure of the commercial power supply through a resistor, gives a signal to the DC circuit through the photocoupler 2 and the photocoupler 3, and its multiplied frequency pulse is given to the control device 4 through the inverter gate, which controls the Frequency discrimination is performed in device 4.

Conventional frequency discrimination will be explained based on the time chart of FIG. Figure E shows the power supply frequency waveform (Japanese case Q50H
Figure 2 shows the voltage waveform applied to the photodiode of photocoupler 2, Figure G shows the voltage waveform applied to the photodiode of photocoupler 3, and diagram H shows the voltage waveform applied to the photodiode of photocoupler 3. This is a pulse waveform applied to the control device 4.

The control device 4 measures the period indicated by ■ or @ in this figure, and determines whether it is 100 Hz or 12'OHz. Whether the period to be determined is ■ (whether it is 0 or not depends on the timing at that time).

Problems to be Solved by the Invention At this time, the characteristics of the photocoupler 2 and the photocoupler 3 shown in FIG.
Well, since they are not the same, the periods of ■ and in FIG. 4 are often not constant and are not exactly 100 Hz or 120 Hz, so a 50/60 Hz town error may occur.

Means for Solving the Problems The present invention solves the above problems by combining two different persimmon odes.
, ', Commercial power Z source with i wave number (50Hz in Japan)
and 60Hz) converted to double frequency 1) 11
Create a source oscillation period that counts the pulse frequency jυ1 by inputting the reliability from the clock generator and the 2-time count unit that counts that the pulse has been input twice to generate the pulse 2.
A counter section that counts the number of cycles, and a counter from the counter section (which checks whether the direct and commercial power supplies are at the same Hz).
141 Separate group f1 (Frequency 1 group 1p data and frequency 2 group 1II-comparison unit that inputs and compares the data, and the comparison) Select whether the result of ■ is frequency 1 or frequency 2. The present invention provides a power supply frequency selection device comprising a selection section for selecting a frequency, and a control section for performing various controls based on the frequency selection results.

Effect: With the above configuration, the present invention obtains a constant measurement cycle by measuring the cycle of two pulse inputs given at a frequency double the power supply frequency, and only when the results match N times in a row does the power supply start. Since the frequency is determined, the power supply frequency can be determined more reliably.

Embodiment FIG. 4 is a block diagram of a power frequency discrimination device of the present invention. The frequency doubler converter circuit in this figure corresponds to 1 in FIG. 2, and the control section has a block configuration shown in 4 in FIG.

The present invention will be explained with reference to FIG. Figure A shows the power frequency waveform, Figure B shows the voltage applied to the photodiode of the photocoupler 2, Figure 0 shows the voltage applied to the photodiode of the photocoupler 3, and Figure D shows the pulse waveform applied to the control device 4. Here, the pulse frequency in diagram D is twice the power supply frequency in diagram A. The pulse period and ri are not constant as described above.

In the present invention, the +■ period, that is, the @ or ■ period, is measured and whether it is within the 50 Hz data range or not.
The power supply frequency (50/60Hz) is determined by comparing whether it is within the data range of 60Hz or 60Hz.

In this case (of course, the periods indicated by is 50Hz or 60
Since it is determined whether the frequency is Hz or not, there is no need for unnecessary frequency discrimination due to external noise or the like. Based on this determination result, the base timer is thereafter counted by a 100 Hz or 120 Hz pulse input, and the same control is performed regardless of the power supply frequency.

Effects of the Invention As described above, the present invention is extremely useful in that reliable frequency discrimination can be performed and it is not affected by external noise.

[Brief explanation of drawings]

Fig. 4 is a pronk configuration diagram of the present invention, Fig. 2 is a circuit diagram for frequency discrimination, Fig. 3 is a timing chart for explaining the present invention, and Fig. 4 is a timing chart for explaining the conventional example. It is a chart. 1... Frequency doubler conversion circuit, 2.a... Photocoupler, 4... Control device. Fig. 4 Control table l Fig. 2 Fig. 3 ←-1→

Claims (2)

[Claims] (1) A frequency conversion circuit that converts a commercial power source with two different frequencies into a double frequency; a clock generation unit that generates a source oscillation period that counts the pulse period from the frequency conversion circuit; and the pulse is input twice. a counter section that inputs a signal from a two-time counting section to count the period of two pulses, and a reference for determining the count value from the counter section and the frequency of the commercial power source; a comparison section that inputs and compares the frequency, reference data, and frequency 2 reference data; a selection section that selects frequency 1 or frequency 2 based on the result of the comparison section; and a decision made by the selection section. A power frequency discrimination device consisting of a processing section that performs various controls based on the following. (2) An N-times coincidence counter section is provided to count whether the result of frequency 1 or frequency 2 matches N times in a row, and it is not until the N-times coincidence counter section counts N times that frequency 1 or frequency 2 matches. 5. The power frequency discriminating device according to claim 4, further comprising a selection section for selecting 2.