JPS62164337A - Feeding system for terminal equipment - Google Patents

Abstract

PURPOSE:To minimize the number of wirings by supplying a oscillating signal with a frequency higher than the frequency band of an information signal to an information line as a power source, frequency-separating the oscillating signal and the information signal by a terminal equipment, converting the separated oscillating signal to a direct current and making it into the power source. CONSTITUTION:A power source circuit 13 provided in parallel to a controller 10 is constituted of an oscillator 14 and a power amplifier 15. The oscillator 14 executes the sine wave oscillation of a constant frequency f0 with the frequency of about 20kHz-30kHz. Both edges of the secondary winding of a transformer T1 are respectively connected through a capacitor C2 and a coil L2 serially connected, to a pair of the information lines 11 respectively. At a terminal equipment 12, a power source separating circuit 20 and an information separating circuit 21 are provided, both edges of the secondary winding of a transformer T2 is connected to a rectifier circuit 22, the oscillating signal is rectified, further, smoothed by a smoothing capacitor CB, made into the direct current power source, and thereafter, the signal is supplied to the power source terminal of a speech network circuit 23.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a power supply system for a terminal, and
This relates to a power supply method for a terminal in a system in which information (ji j3) is transmitted and received between the terminal and the terminal via an information line.

Conventional Technology 11 Recently, for example, in the home, home office systems that centrally manage and control air systems, rice cookers, security cameras, and water heaters are becoming increasingly popular. I'm here.

Each terminal device that controls individual equipment such as the air conditioner in the home automation system described above does not have its own power source, but receives power from the central controller (controller) that controls the entire system. Also,
In the Baum telephone system, each terminal similarly receives power from a central unit (controller).

The conventional power supply systems for the terminals connected to the above-mentioned Baum automation system and home telephone system are the 2-wire type (b) as shown in Figure 2, and the 4-wire type (6) as shown in Figure 30. I have a throat.

In FIG. 2, a direct current is superimposed on an information line 2 connecting a controller 1, which is a central device of a home telephone system, and each terminal, and power is supplied to each terminal.

At this time, it is necessary for each information line 2 (, 1 to maintain equilibrium and independence, so each information line 2 has an independent DC current;
Since the DC power source 3 has low impedance, a coil 1.1 is provided. In FIG. 3, a controller 5 of the home prephone system and each terminal are connected by an information line 6, and a power line is connected to each terminal from terminals 7a and 7b of a power supply circuit 7 installed in parallel with the controller 5. 8
Power is supplied via.

Problems to be Solved by the Invention In the system shown in Figure 2, since the F limit of the frequency of the telephone voice signal as the information signal is 400H2, the coil 1-1 requires an inductance of about 11''. . Figure 4 (A> shows the relationship between the impedance of this coil L1 and the frequency. Naturally, the coil L1 has a direct current (
0.5 A or more F) flows. When the coil has an iron core, the iron core is magnetically saturated by the direct current, so the relationship between the inductance and the direct current is as shown in FIG. 4(B).

Therefore, there is a problem in that the coil ]-1 must be large and expensive in order to maintain sufficient inductance even when direct current flows.

Also, as shown in Figure 3 (in the method shown, if there are many terminals,
Wiring becomes crowded. In addition, each terminal has 2 wires//4
A speech network circuit for line conversion is provided,
This speech network circuit detects the resistance between the lines by detecting the power supply, and automatically adjusts the internal resistance according to this resistance between the lines to keep the rising sound current constant. However, since the AC resistance of the information line 6 and the DC resistance of the power supply line 8 do not necessarily match, there is a problem in that the automatic adjustment described above is difficult.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a power supply system for a terminal that solves the above-mentioned problems by supplying an oscillation signal as a power source to the terminal via an information line.

Means for Solving the Problems In the present invention, the central unit and the terminals are connected by an information line to transmit and receive information signals. An oscillation signal having a frequency higher than the frequency band of the information signal is supplied to this information line as a power source.

The terminal frequency separates the oscillation signal and the information signal, and converts the separated oscillation (mi) into direct current and uses it as a power source.

Effect In the present invention, since the oscillation No. 11 has a high frequency,
The coils, etc. used can be small and inexpensive, and since the power is supplied via an information line, the number of wires is small, making it less appealing.

Embodiment FIG. 1 shows a circuit diagram of an embodiment of a home telephone system using the method of the present invention. In the figure, 10 is a controller as a central device of the home telephone system, and a terminal 12 is connected to each pair of information lines 11 connected to the controller 10. Audio signals such as information signals are transmitted and received between them. Here, the telephone voice signal is shown in FIG.
/1. OOHz~3. /I kHz has the same wave number band.

A power supply circuit 13 installed in parallel with the controller 10 is an oscillator 1
4 and a power amplifier 15. Oscillator 1
/1 performs sine wave oscillation with a constant frequency f of approximately 20 kHz to 30 kl-(Z).

Although each transformer can be made smaller, the power amplifier 1/I
O) Since the configuration is circular and the occurrence of electromagnetic interference becomes a problem, the F limit of the oscillation frequency is determined. Also,
If the oscillation frequency is low, interference with the audio signal becomes a problem, so the F limit of the oscillation frequency is determined, and the above-mentioned frequency is selected based on this. The output oscillation signal of the oscillator 14 is ``gravity amplified'' by the power amplifier 15 and has an effective value of, for example, 20V.
~30V is a sine wave of several watts to several 10 watts, and terminal 1
3a.

It is output from 13b. Here, we set it as a sine wave (, L
This is to prevent electromagnetic interference and reduce network losses of coils, capacitors, transformers, etc., which will be described later.

D test of the above power supply circuit 13: Children 13a and 13b each information! ! Terminal 16 of mixing circuit 16 provided every 311
a and 16b are connected to each other. One section of the primary winding of a transformer T+ is connected to terminals 16a and 16b of the mixing circuit 16. Both ends of the secondary δ line of the transformer T1 are connected to each of the pair of information lines 11 via a series-connected capacitor C2 and coil [-2]. 1 to Lance 1 has a frequency f.

(20kHz≦f≦30k)-1z) and sufficiently transmits an oscillation signal of 20Vrms to 3QVrmS. Further, the resonant frequency of the series circuit composed of the capacitor C21 and the coil L2 is the frequency f of the oscillation signal.

J, which is the same as , has been selected. As a result, the connection point 11a with the information line 11 of the mixing circuit 1G.

11bJ, the impedance/frequency characteristics of the mixing circuit 16 when looking at the terminals 16a, 16b are as shown in FIG. 6, and the frequency is f. It has a sufficiently low impedance for all frequencies, and a sufficiently high impedance for other frequencies.

The terminal device 12 has a power separation circuit 20. An information separation circuit 21 is provided. In the power supply separation circuit 20, the information line 1
A series circuit consisting of a coil L3 and a capacitor C3 is connected to each of the connection points 118.11b of 1, and the primary winding of the transformer T2 is connected to the other end of this series circuit. This power supply separation circuit 20 has the same frequency characteristics as in FIG. 6, and extracts an oscillation signal of frequency fo from both ends of the secondary winding as a power supply. Both ends of the secondary winding of the transformer T2 are connected to a rectifier circuit 22, where the oscillation signal F is rectified and smoothed by a smoothing coil Co, so that the DC current J≦
After being returned to 1, it is supplied to the power supply terminal of the work circuit 23 to the speech network 1.

A3 in the information separation circuit 21, connection point 11 of the information line 11
A, 11b are connected to a parallel circuit of a coil 1-4 and a capacitor C4, and the other end of this parallel circuit is connected to the primary winding of the Herance T3.

The information component 1iIt circuit 21 has a frequency characteristic that attenuates only the oscillation signal of the frequency fo, and does not take out the voice signal of the telephone 1 shown in FIG. 5 from the secondary winding. The audio signal taken out from both sides of this secondary winding is sent to the speaker network circuit 23.
information is supplied to the C8 input terminal. The speech network circuit 23 detects the inter-line resistance of the information line 11 using the DC voltage supplied to its power supply terminal, automatically adjusts the internal resistance according to the inter-line resistance, and performs 2-wire/4-wire conversion.

In response to this, the audio signal transmitted from the commi roller 11 is output from the terminal 24, and the audio signal No. 15 that enters the terminal 25 is sent to the information separation circuit 21 as information! 211.

Since power is supplied to each terminal 12 using an oscillation signal with a frequency of fo, the coils are connected to each other at a frequency of 2°1-3. L4,
Capacitors C2, C3, C4, transformer T+, T2
, T3 are small and inexpensive, and can easily adjust the tone automatically using a speech network, and although the number of wires between the central unit and the terminals is large, the method shown in the second diagram does not require much wiring. It flows in half. Especially coil L,2,
L3, l-, + need only have an inductance of 1 or less than the number of coil L1 shown in the second figure, and since no direct current flows, coil L2. 1-3 and 14 need only be very small.

In addition, when each terminal 12 requires a different lζ power supply voltage, it is possible to easily adapt to λ1 by changing the winding ratio of the -b transformer T2, and regardless of the number of information lines 11, the power supply circuit 13 One circuit is sufficient. Furthermore, each pair of information lines 11 has no polarity, making wiring work very easy.

J'3, the system shown in FIG. It may be a bus type for transmitting and receiving information, or it may be a star type for transmitting and receiving information signals between each terminal 12 and the controller 10 by connecting each pair of information lines 11 to a single terminal. Te-b is good. Further, although the above embodiment has been explained using the Baume-Telebon system as an example, it is of course applicable to the C3 Ebohm automation system.

Effects of the Invention As shown in (g) and (e), the power supply system of the terminal device according to the present invention uses oscillation (used because the oscillation signal is a high frequency).

Parts such as capacitors and transformers are small/%ll and cheap f+
Since the oscillation signal is sent using the information line, the number of wiring is small, and the information line has no poles and edges, making wiring work easy.

[Brief explanation of drawings]

Figure 1 is a circuit configuration diagram of a single color/one-color example of a system to which the present invention is applied; Figures 2 and 3 are diagrams used to explain the various components of the conventional system; Figure 4; 2 is a diagram for explaining the coil shown in Figure 2, Figure 5 is a diagram showing the frequency spectrum of a telephone voice signal, and Figure 6 is a diagram that does not show the frequency characteristics of the circuit shown in Figure 1. . 10... Controller, 11... Information line, 12...
・Terminal device, 13...power supply circuit, 16...mixing circuit,
20...Power separation circuit, 21...Information division (circuit).Patent applicant: Japan Victor Co., Ltd.

Claims (1)

[Claims] In a power supply system for a terminal device in a system that transmits and receives information signals between a central device and a terminal device via an information line, an oscillation signal with a frequency higher than the frequency band of the information signal is supplied to the information line as a power source. A power feeding system for a terminal device, characterized in that the terminal device frequency-separates the oscillation signal and the information signal.