JPH0286223A - Impedance converter - Google Patents

Abstract

PURPOSE:To ensure the lighting line carrier communication by varying the impedance to a carrier according to preset prescribed conditions. CONSTITUTION:A control terminal equipment 1 is connected to lighting lines 3a, 3b and a series impedance of an impedance converter 2 comprising capacitive impedances 4a, 4b and an inductive impedance 5 connects to the lighting lines 3a, 3b via impedance changeover relay contacts 6a, 6b, and impedance changeover relay coils 7a, 7b are connected to a control section 8 of the control terminal equipment 1. Thus, the impedance with respect to a carrier is varied according to the preset prescribed conditions to move a transmission zero point thereby enabling the communication even if the communication is disabled due to the presence of the transmission zero point.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a frame and light transport control system, and particularly to an impedance conversion device suitable for ensuring reliability of conduction when a capacitive load is connected.

[Conventional technology]

Conventionally, as a method to prevent equipment from becoming low impedance to the carrier signal due to noise prevention capacitors, etc.,
It has been proposed in JP-A-62-107535 to provide an impedance upper in series with the control load at the end of the control foam.

[Problem to be solved by the invention No. 5] The above-mentioned conventional technology is effective when devices connected to power lines are always connected via a control terminal, but it is effective when devices connected to a power line are always connected via a control terminal. No consideration was given to devices that are used while moving, such as vacuum cleaners, and it was not effective when such devices were capacitive due to noise prevention capacitors, etc.

An object of the present invention is to ensure that power line carrier communication can be carried out reliably even when such capacitive equipment is connected.

[Means to solve all IA issues]

The above objective can be achieved by changing the impedance to the carrier wave according to predetermined conditions set in advance in the power line carrier open side system. In this case, not only will the transmitted wave become smaller due to the low impedance of the device itself (but also the series resonance phenomenon will occur due to the inductance of one lamp and the capacitance of the device, and the impedance to the carrier wave will become extremely small (see below). However, when an impedance change eO is connected, the series resonance point shifts, so the transmission zero point moves according to the predetermined conditions, and the carrier wave is If reception is not possible, retransmit the carrier wave after the transmission zero point moves so that reception can be made.

You will be able to communicate reliably.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. t-21 to 7.

FIG. 1 shows the impedance conversion j! included in the control terminal 1 of the electric light conveyance control system shown in FIG. 2, which is an embodiment of the present invention. FIG. 2 is a sketch of device 2. Control terminal 1 has 4 lights @3
The capacitive impedance 4α of the impedance converter ji2, the series impedance of the capacitive impedance 46 and the inductive impedance 5 are connected to the power lines 5a and 34 through the impedance switching relay contact 6-164't-. It is connected. The impedance switching relay coil 7-174 is connected to the control section 8 of the control terminal 1.
The control section 8 serves as a control section of the control terminal 10 and a control section of the impedance conversion device 2.

FIG. 2 is a schematic diagram of a power line carrier control system to which this embodiment is applied, in which a blocking filter 9 is provided at the base of the indoor power line to prevent leakage of carrier signals to the outdoors, and each control terminal 1 .1', a control terminal 1 having a built-in impedance conversion device of this embodiment, and other l
! I control terminal 11 and control terminal 1.11t-not-intervening equipment 11g are connected to indoor light +II5. Further, a device 114 is connected to the control terminal 1 as a control load by means of an output switch 14 of a control relay contact 15 which is opened and closed by a control relay coil 12 and an indoor electric light @54. Also, other systems (
Similarly, the device 11C is connected to the terminal 1' of the terminal 511. An impedance upper 15 is connected between the output relay contacts 13 and the output terminals 14 of the control terminals 1 and 1' to prevent the impedance of the equipment 114.11C from affecting the impedance of the indoor power line 3.

If the device 11- is a capacitive load, its equivalent capacity 16
Let co be the inductance per unit length of the indoor power line 5, and let the inductance per unit length of the indoor power line 5 be 17 t-Lo, then the equinodal circuit of the indoor power line will be approximately as shown in Fig. 3. The impedance characteristic becomes an impedance characteristic 18 shown in FIG. 4, and a transmission zero point 19 where IZ4t becomes minimum occurs at a distance of 0 from the device 11g due to a series resonance phenomenon. Here, the 5JoO value is ノ'-(2t f□)'L, assuming that the frequency of the carrier wave is t-fo.
oC.

It becomes. As is clear from this formula, the equivalent capacity 1
The value of 0 changes depending on the value of 6, so if the control terminal is at such a transmission zero point 19, if the equivalent capacity 16 is set in advance and changed under the specified conditions, the transmission zero point will move. The level of the carrier wave will rise and communication will be reliable5.
become. 5 and 6 are time charts showing the relationship between communication timing and the operation of the impedance conversion device 2, and FIG. 7 is an operation flow diagram of the control unit 8. In the case of this practical example, communication is repeated a maximum of three times until it is performed correctly. The control @control ii8 of the terminal 1 checks the presence or absence of carrier wave signal communication 2oα (27), and if the communication 20- is for the own machine, switches the control relay contact 16 on and off using the control relay coil 12 (
2,9) Control the device 114 aL, if the communication 20g is not for your own machine, check the length of the communication 20g and if Ill, then (3o) T after the end of the communication 20g, S after /2, turn on. During the period 21, the impedance switching relay coil 7a turns on the impedance switching relay contact 6nji.
1), then check the second intersection 204 for the presence of money 52).

Second exchange [If there is 20+, the reception level at that time is 25
41i7J4 All (3!1) If it is below the predetermined level Eo, the impedance switching relay contact 6-8t''81 is turned on at the same time as the end of the on period 21 by the impedance switching relay coil 74 and held for the on period 22. (54).-If the exchange 20a is the length of TI' like exchange!24-, the impedance switching relay contact will be connected for the SI on period 250 after 72 after the end of the communication 24-. Turn on 6- (35) and check whether there is communication 24 (36), and if there is communication 4M24, turn on impedance switching relay contact 6b at the same time as the end of a on period 25, and turn on S, on period 260. hold for a while (
37). In this way, in this embodiment, the impedance conversion device is operated a predetermined number of times in a predetermined period according to the length of the communication and the reception level based on the timing of the communication, and the impedance at the time of the contact is changed up to three times. Since the transmission zero point is moved, any signal can be received by the control 1 song.

〔Effect of the invention〕

According to the present invention, since the impedance to the V carrier wave is changed according to predetermined conditions set in advance, even if there is a transmission zero point and communication is impossible, the transmission zero point can be moved and communication can be achieved. Since it is possible to respond whenever and wherever it occurs, even during construction when it is unclear what will be connected to which outlet, the system can be used to prevent power failures from occurring. Additionally, if there is a device that is moved around, such as a vacuum cleaner, the transmission zero point will also move, but communication between each terminal is possible even in such cases. If the length and timing of communication are short, the impedance conversion device can be simplified by changing the impedance to the carrier wave at regular intervals, and if the carrier wave signal is damaged, the impedance "d" is changed at regular intervals a predetermined number of times. -K allows communication under different impedance conditions at accurate timing.Also, by changing the impedance change period t-, depending on the length of the received signal, communication is possible. It can also handle the communication of modulated data, and by changing the range in which the impedance characteristics are plotted according to the size of the received nine carrier waves, it is possible to perform impedance f conversion suitable for the line impedance. By installing an impedance conversion g device in parallel with the control C1IJ terminal in all device control lines rtj system a, the control section can be shared, and there is no need to create a dedicated impedance conversion device (also system You will be able to assemble.

[Brief explanation of drawings]

Fig. 1 is a structural diagram of a nine-impedance converter t built into the control end of an embodiment of the present invention, Fig. 2 is a configuration diagram of a power line conveyance control system of this embodiment, and Fig. 3 is in the section. The equivalent circuit diagram of a power line, WX4 is an impedance characteristic diagram, FIGS. 5 and 6 are time charts of communication timing and impedance switching, and FIG. 7 is an operation 70 diagram of this embodiment. 1... Control 1 end, 2... Impedance! conversion device. Figure 1 Representative Patent Attorney Masaru Ogawa

Claims (1)

[Claims] 1. In a power line carrier control system that remotely controls electrical equipment by superimposing a carrier wave signal on an indoor power line, an impedance conversion characterized in that the impedance to the carrier wave is changed according to predetermined conditions set in advance. Device.