JPS60121810A - Noise preventing filter of carrier frequency band of carrier type interphone - Google Patents

Abstract

PURPOSE:To prevent noise to a interphone by providing an electric wire with a parallel circuit of a retardation coil and a capacitor which has a resonance frequency in the frequency band of a carrier type interphone and also capacitors at the power source side and load side in parallel. CONSTITUTION:The retardation coil 18 having current capacity coordinate with a breaker for branching of a distribution board in terms of short-circuit capacity during the short-circuiting of load equipment and a capacitor C19 parallel to it are provided between the electric wire and load equipment. The resonance frequency between the coils 18 and C19 is set close to the carrier frequency band of the carrier type interphone, and a constant is so determined to obtain high impedance to the carrier frequency band of the frequency band of the interphone and extremely low impedance at the commercial frequency. Further, C20 and C21 are provided between power source-side terminals 14 and 15 and load side terminals 16 and 17 of this resonance circuit. The C20 and C21 absorb high frequency noises generated various equipment utilizing a high frequency inverter to prevent noises from flowing through the electric wire, and evil influence of the noises upon the carrier type interphone is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to the prevention of noise in the carrier frequency band of a carrier type intercom that uses electric power lines to prevent noise from equipment that generates noise that has an adverse effect on the carrier type intercom. Concerning filters〇 Conventional configuration and its problems A carrier type intercom using a lighting line is 230K ll
The FM system, which has six frequencies spaced at intervals of 40Kllz between z and 430Kllz as center frequencies, and each frequency band is ±11KIIz, is approved by type certification under the Radio Law. The revision of the Radio Law in 1957 changed type certification from individual certification, which accelerated the spread of carrier-type intercoms because of the convenience of eliminating the need for separate communication line construction. On the other hand, devices using high-frequency inverters, including household electrical devices, have been increasing at a rapid pace in recent years. And the frequency of the high frequency inverter is almost 10Ktlz~100I
It is distributed in CIJZ. For example, the frequency of an electromagnetic cooker is distributed between 20 KHz and 3° KIIZ, and the frequency of a high-frequency lighting fluorescent lamp is distributed between 36 KHz and 48 KHzK. These devices that use high-frequency inverters cause their fundamental waves and harmonics to flow into the lighting line as noise.

Due to these noises, carrier-type intercoms can be affected to the extent that it is impossible to make a call during a call, or generate an unpleasant gurgling sound when on standby when not talking.The problem has come to light with the spread of carrier-type intercoms and devices that use high-frequency inverters. I've done it.

Figure 1 is an example of a wiring diagram for one home's electric light lines. In the figure, 1 is the main breaker - 2, 3, 4 are the branch breakers + 2', 3', 4' tt1 The power lines connected from the branch breakers 2', 3.4 - 6, 6 are the conveyor With the intercom, you can make calls just by plugging in the power outlet. This is an electrical appliance that uses a 7-digit high-frequency inverter, and is a filter that prevents the noise generated by the electrical appliance from flowing into the power line. Further, the electric appliance 7 may be connected to another household connected to the same pole transformer.

First, the filter 8 needs to have sufficient short-circuit capacity so that it will not be damaged by the short-circuit current that flows through the breaker 2 for one branch and opens the breaker 2 when the electric appliance A is short-circuited. 9 is a power supply terminal.

The filter of the circuit shown in Fig. 2 is currently used to prevent noise in carrier intercoms, and p, 1o,
q11rJ blockage wire with inductance value of 120 μH -
12 is a capacitor with a capacity of 0.1 μF, 13 is a 6A fuse, 14.16 is a terminal connected to the power supply side, 16.
17 is a terminal into which a load-side outlet is inserted. The short-circuit capacity is coordinated with respect to the short-circuit of the fuse of the blocking coil 10.11fi6A.

Filter f-230KlIZ ~43oKl+ in Figure 2
There is little attenuation in the frequency band of Z's carrier type intercom, and it was effective against noise generated from television receivers, kotatsu, dimmers, etc. before equipment using high-frequency inverters became widespread. However, the characteristics are insufficient for electromagnetic cookers and high-frequency fluorescent lights, and they are affected by the noise generated by them.

In addition, short-circuit capacity is also protected by a fuse, so
If the load is short-circuited, maintenance such as replacing the fuse is time consuming.

Purpose of the Invention The purpose of the present invention is to absorb high frequency noise generated from various devices using high frequency inverters to prevent the noise from flowing into power lines, and to prevent such noise from adversely affecting carrier type intercoms. It is something to do.

Structure of the Invention As a structure for that purpose, the present invention has a voltage of -100V or 200V.
Between the V-system power line and the load equipment, a blocking wire ring with a current capacity that is coordinated with the branch breaker of the distribution board and the short circuit capacity in the event of a short circuit of the load equipment is installed, and the carrier frequency of the single carrier type intercom is set. A resonant circuit is constructed by connecting a capacitor in parallel with the blockage wire so as to have a resonant frequency in the band and its vicinity, and a capacitor is connected in parallel to the power supply side and the load side at both ends of the resonant circuit. DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described.

Fig. 3 shows one embodiment of the present invention, and Fig. 5 in a box shows another embodiment. Fig. 4 is a characteristic diagram of the embodiment shown in Fig. 3, and Fig. 6
The figure is a characteristic diagram of the embodiment shown in Fig. 5.

The attenuation ratio of the carrier intercom frequency band of ='-, 230 Kllz to 430 Kllz is 135 dB or more.

First, the embodiment shown in FIG. 3 will be explained.

14.16 are the same as in Figure 2, and the power supply side terminals 16 and 17id, which connect to the power line, and the load side terminal 18, which connects the outlet to the load side, are blocking wires, and the commercial frequency current of one load device is carried through this line. flows through the ring.

The short-circuit capacity for the current of this coil 18 must be coordinated with the branch breaker of the distribution board that supplies electricity to the load equipment when the load equipment is short-circuited.

In other words, by providing a branch breaker with a capacity sufficient to withstand short-circuit opening, components having an opening function such as a shifuse can be eliminated. 19 Input in parallel with flow line ring 18, a TZ condenser is used to provide a resonant frequency in the frequency band of one intercom and frequencies in its vicinity, and constants are determined for each so as to have a high impedance for the frequency band of the intercom. The impedance should be very low. Also, if the Q becomes very sharp with respect to the parallel resonance frequency, the single-line ring 18. A resistor may be inserted in parallel with the capacitor 19 to lower the Q. Capacitors 20 and 21 on the power supply side and the load side are connected to both ends of the parallel circuit of the coil 18 and the capacitor 19. The capacitors 20 and 21 have a low impedance for interphone band frequencies and a high impedance for commercial frequencies. The capacitor 21 has a low impedance against noise in the intercom frequency band emitted by the load equipment, and the noise is shunted to the capacitor 21 to lower the noise level. The twisted capacitor 20 eliminates most of the noise generated at both ends of the capacitor 21 between the coil 18 and the capacitor 1.
The impedance should be low so that the power is distributed to both ends of the power line, and the impedance should be low so that even if the impedance of the two power lines changes, the level of the frequency of the intercom band that leaks to the two power lines will be below a certain value. There is. In other words, it does not depend on the load.

To summarize the above explanation, the parallel circuit of wire ring 18 and capacitor 19 has a high impedance for the frequency of the intercom band, absorbs most of the noise, and capacitor 2
1 to suppress noise generation, and the capacitor 20 has a low impedance to eliminate the influence of other load devices. For commercial frequencies, the value of the coil 18 is made small to provide one-short circuit capacity, and the voltage drop with respect to 6011z (6011z) is suppressed to about 0.1 V. Fig. 4 shows the inductance value of wire ring 18 -15.7μH, capacitor 19 (D capacitance i = 0.022μF, capacitance of capacitor 2o = 03μF, capacitance of capacitor 21 -0.3
The characteristics when the value is μF are shown.

FIG. 5 shows another embodiment. In the embodiment of FIG. 3, the impedance for the frequency of the intercom band seen from the power line is lowered by the capacitor 20, and the transmission power of the intercom is consumed by this capacitor 20. (For example, in order to transmit a signal to an intercom installed on a different phase with a single-phase three-wire power line, the signal must be transmitted through a pole transformer, so the signal is severely attenuated.) , you may not be able to make a call if the signal level drops). In the embodiment shown in FIG. 6, a blocking coil 22 is inserted in series with the power line on the power supply side of the embodiment shown in FIG. 3 to have the role of increasing the impedance with respect to the signal frequency of the intercom. Figure 6 is a characteristic diagram when the inductance value of the blocking wire ring 22 is -10 μH. Noise characteristic diagram of the electric light line during operation of the electromagnetic cooker when the conventional filter shown in Fig. 2 is attached - Fig. 9, operation of the electromagnetic cooker when the filters of Figs. 3 and 6 are attached to Fig. 1Q A diagram of the noise characteristics of the electric light line at the time,
According to this, it is clear that most of the noise from the electromagnetic cooker has been eliminated.

Effects of the Invention As described above, the noise prevention filter of the present invention provides the following first-order effects.

(1) It is possible to eliminate the frequency band troubles of a carrier type intercom of a load device using a high frequency input ζ-intercom without being affected by another load, and to prevent an adverse effect on intercom calls.

(2) By providing sufficient short-circuit capacity, the reduction in reliability of the power line can be eliminated by incorporating the filter of the present invention.

[Brief explanation of the drawing]

Figure 1 is a wiring diagram of a household electric light line, Figure 2 is a wiring diagram of a conventional noise prevention filter, Figure 3 is a wiring diagram of a noise prevention filter according to an embodiment of the present invention, and Figure 4 is a wiring diagram of a conventional noise prevention filter. A transmission ratio characteristic diagram of the embodiment shown in the figure - FIG. 5 is a wiring diagram of a noise prevention filter according to another embodiment of the present invention, FIG. 6 is a transmission ratio characteristic diagram of the embodiment of FIG. Figures 8, 9, and 10 are the hawks without lettering.
FIG. 7 is a noise characteristic diagram of the electric light line when the electric cooker is operated when the filter shown in the figure is attached and when the filter of FIG. 6 is attached. 14.16...-Power supply side terminal-16, 17...
・Load side terminal, 18.2'2... Blocking wire ring, 1'
9,20゜21... Capacitor. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Fig. 2 Fig. 3 Fig. 4 Fig. 11 (shi) (lku indulgence) Fig. 5 Fig. 6 Nau Tomomaki cxig Fig. 7 Fusuku 0tHz) Fig. 8 Moon rose && CWH 'lノ

Claims (2)

[Claims] (1) Between the 100V-4ftd320OV system power line and load equipment, a blocking wire ring having a current capacity that is coordinated with the branching breaker of the distribution board in short-circuit capacity in the event of a short-circuit of the load equipment is provided, A resonant circuit is constructed by connecting a capacitor in parallel with the blocking wire so as to have a resonant frequency in and around the carrier frequency band of the carrier type intercom, and nine A noise prevention filter for the carrier frequency band of a carrier type intercom with each capacitor connected in parallel. (2) A structure according to claim (1) in which another blocking wire is connected in series to the power source side of the capacitor connected in parallel to the power source side of the resonant circuit and connected to the power line. Noise prevention filter for carrier frequency band of carrier type intercom.