JPS60207074A - Optical power measuring apparatus - Google Patents

Abstract

PURPOSE:To make it possible to directly and optically measure effective power and apparent power, by separating an effective power component and an apparent power component from an instantaneous power component received by a light receiving element by a filter. CONSTITUTION:A current I is supplied to a magneto-optical effect element 4 from the power line of a power source side to be sent to a load side and voltage V is applied to an electrooptical effect element 5. Light from a light emitting diode 1 is received by a photodiode 9 through a lens 2, a polarizer 3, elements 4, 5, an 1/4 wavelength plate 6, a light detector 7 and a lens 8 while the light receiving output is inputted to a differential amplifier 12 and the difference voltage with reference voltage from a variable reference voltage source 13 is inputted to a low pass filter 14 as instantaneous power to take out an effective power component. The AC signal from a high pass filter 15 is inputted to an integrator circuit 17 through a diode 16 and an apparent power component is taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Application This invention relates to an optical power measuring device that measures power using light.

(b) Background Art As a device for optically measuring electric power, the present applicant has proposed a device that has attracted much attention. FIG. 1 shows this device, and reference numeral 1 designates a light emitting diode. Output light from the light emitting diode 1 is incident on a lens 2, condensed, and incident on a polarizer. Directly polarized light that passes through this polarizer filter is used as a magneto-optical effect element (Faraday effect).
4, the direction of polarization is rotated by the Phaodi fruit. Furthermore, when the rotated linearly polarized wave is passed through a vertical electro-optic effect element (Pockels element) 5 to which voltage ■ is applied, the applied voltage V is caused by the Pockels effect.
It changes into elliptically polarized wave due to a change in phase proportional to . The resulting leaked light is further passed through the 174-wavelength plate 6 to be corrected so as to obtain good linearity with respect to the measured power. Further, the light output from the quarter-wave plate 6 passes through an analyzer 7 installed in a negative direction relative to the ten-thousand direction of the polarizer 6, passes through a lens 8, and is received by a photodiode 9. Ru.

In the above-mentioned device, if the average light receiving power received by the photodiode 9 is IJo, the light power P received by the first diode 9 is given by the following equation.

1,'= )'o/2 (1+5ink, V-5ink
2V) -(t) where, k2 is the magneto-optic effect element 4. This is a constant determined by the cut, length, thickness, etc. of the crystal of the electro-optic effect element 5.

+1) In the formula, k, V((21〈〈/4
In the case of 0 1) = -(1++■・k2i) -(2+.In other words, the optical output P is the product of voltage V and current 1 by dividing PC/2 by Nakagami, that is, it is proportional to the power. I get the output.

(C) Problem Point The optical output P is given by the product of the voltage ■ and the current I, so if the voltage V and the current 1 are alternating current, the optical output P
had the disadvantage that it could only measure instantaneous power. For this reason, there was an inconvenience that it was not possible to distinguish between active power and apparent power.

(-4 Purpose) This invention was made based on the above circumstances, and its purpose is to be able to extract an active power component or an apparent power component from a light output related to instantaneous power received by a light receiving element. An object of the present invention is to provide an optical power measurement device.

+1 Implementation Shiori: Hereinafter, one embodiment of the present invention will be described based on FIG. 2. The portion E in FIG. 2 surrounded by No. 91 11 is the light emitting diode 1. shown in FIG. Lens 2.
Abrasive optical effect 4. Electro-optic effect element 5 + '74
Wave plate 6. Analyzer7. It includes a lens 8 and a photodiode 9. Here, 1 car of current is supplied to the magneto-optic effect element 4 from the power line on the power source side, and the load 1)+1
1, and a voltage V is applied to the electro-optic effect element 5 from the power source. And photodiode 9
The received light output from the differential amplifier 12 is applied to the positive input terminal of the differential amplifier 12. - 10,000, a base voltage is applied to the negative input terminal of the differential amplifier 12 from a variable reference voltage source 15. The differential amplifier 12 amplifies the difference between the two input voltages and obtains an output signal proportional to the voltage V and the current (2), that is, the instantaneous power (2) and (2), and the low-pass filter 14 and the bypass filter 1
Manpower to 5. The low-pass filter 14 passes signals below the music frequency and removes signals above the commercial frequency, and only the active power component of the instantaneous power is extracted from the low-pass filter 14. - The bypass filter 5 passes signals above the commercial frequency and removes signals below the commercial frequency, and the AC signal output from the bypass filter 5 is input to the diode 16. The output rectified by the diode 16 is given to an integrating circuit 17, where the wave height of the manually input AC signal is taken out, and the output is given as the apparent power component of the instantaneous power.

More specifically, the amount of light received by the photodiode 9 is calculated by equation (2), P=Pc/2 (1+, 1V-, 2). Therefore, if the reference voltage 1 of the basic thread voltage source 16 is set to a voltage corresponding to the received light output 4, the differential amplifier 12
From I! An output directly proportional to ok and vo is obtained. Here, voltage ■ and current ■ are V = VT VB
sinwt, I = V'j 114sin (wt
10) - (3) ■ 几, 1 几 is the effective 1 shift, 4 is the phase difference between the voltage V and the current ■,
shall be. From equation (3), ■4. :; ■4 is also 114 cos9-V14II (co
s(2ω+4)−(4) is obtained. In equation (4), the first term VBI 1. L
CO59IIJ''-active power is expressed as the second term vl (I 几 indicates the apparent power. Therefore, the instantaneous power output from the differential amplifier 12 corresponding to equation (4) is passed through the low-pass filter 15. As a result, the second term, which is the AC component of the commercial frequency, is removed and only the active power component of the first term is extracted.Furthermore, when the instantaneous power output corresponding to equation (4) is passed through the bypass filter 15, The first term of the DC component is removed and the second term of the AC component is output.Furthermore, the output of the no-pass filter 15 is rectified via the diode 16, and the second term of equation (4) is output in the integrating circuit 17. The wave height of the alternating current component, Vl (If), is determined and output as the apparent power component.

(f) Effects As explained above, according to the present invention, only the instantaneous power component directly proportional to the product of the current supplied to the magneto-optic effect element and the voltage applied to the electro-optic effect element is extracted, and this instantaneous power component is extracted. Since it is equipped with a low-pass filter that separates only the active power component from the power components, it is convenient because the active power can be directly measured optically.

Further, since the present invention can separate only the apparent power component from the instantaneous power components, the apparent power can be directly measured optically, which is convenient.

This optical power measuring device can be used in a wide range of applications, such as an integrating power meter.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of an optical power measuring device, and FIG. 2 is a block diagram showing an embodiment of the present invention. 1...Light-emitting diode L...Polarizer 4...Magneto-optic effect element 5...Electro-optic effect element 6...1/wavelength Board 7...
...Analyzer 9...Photodiode 12.
... Differential amplifier 15 ... Reference voltage source 14
......Low bass filter 5...Bypass filter -6...Diode 17...
...Integrator circuit patent applicant Sumitomo Electric Industries, Ltd.

Claims (2)

[Claims] (1) In an optical power measuring device that includes a light emitting source, a magneto-optical effect element, an 'r4 optical effect element, and a light receiving element, and measures AC power by simultaneous effects of the Faraday effect and the Pockels effect. Instantaneous power that removes components unrelated to the product of the current supplied to the magneto-optic effect element and the voltage applied to the electro-optic effect element from the output of the light-receiving element, and extracts only the instantaneous power component directly proportional to the ram. An optical power measurement device comprising: an extraction means; and a low-pass filter that passes a portion of the instantaneous power component below a commercial frequency to extract an active power component. (2) In an optical power measurement device that includes a light emitting source, a magneto-optic effect element, an electro-optic effect element, and a light receiving element, and measures AC power by the simultaneous effects of the Faraday effect and the Pockels effect, the power is supplied to the magneto-optic effect element. instantaneous power extraction means for removing components unrelated to the current applied to the electro-optical effect element and the voltage applied to the electro-optic effect element from the light receiving output of the light receiving element and extracting only the instantaneous power component directly proportional to the product; Optical power measurement comprising: a bypass filter that passes a frequency equal to or higher than the flex frequency among power components; and a rectifier-integrator circuit that reduces the amplitude of the output from the bypass filter and outputs the instantaneous power as apparent power. Device.