JPS63227128A - Power line carrier transmission/reception equipment - Google Patents

Abstract

PURPOSE:To surely transmit a signal by detecting an amplitude control use signal at the same position as a connecting position of a transmitting device or at its adjacent position, and bringing an amplitude level of a carrier signal of the transmitting device to a variable control in accordance with its amplitude level. CONSTITUTION:A controller 21 which functions as a transmission equipment, and reception equipments 3-1-3-n are connected to a power line 1, and each electric apparatus, for instance, an illuminating lamp 4, a TV 5, and a refrigerator are connected to the devices 3-1-3-n. A signal generator 20 has a function for superposing an amplitude control use signal having a frequency being adjacent to a carrier-frequency of a controller 21, and also, an amplitude of a prescribed level, to a voltage waveform of the power line 1, and connected to the most distant position of the power line from the controller 21. On the other hand, the controller 21 is provided with a means for detecting the amplitude control use signal superposed to the voltage waveform applied to the power line 1 and bringing an amplitude level of a carrier signal to a variable control in accordance with its amplitude level. In such a way, even if the transmission line impedance is varied, the signal can be transmitted surely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] <Industrial Application Field> The present invention relates to a power line carrier transmitting/receiving device that superimposes a control signal or the like on a voltage waveform applied to a power line and transmits the superposed signal.

(Prior Art) This type of device is applied, for example, to what is called a home controller that controls the operation of various electrical devices in the home. FIG. 4 is an overall configuration diagram of this device,
A controller 2 functioning as a transmitting device and each receiving device 3-1 to 3- are connected to a power line (distribution line) 1 wired in the home.
n are connected to each of the receiving bags @3-1 to 3-n, such as lighting W! 4. Television 5. A refrigerator 6 is connected. As shown in the block diagram of FIG. 5, the controller 2 controls the operation of each electrical device, that is, starts, stops, and
An operating section 7 is provided for inputting settings such as an operating period, and information inputted from the operating section 7 is sent to a control section 8. This control section 8 determines the information input by operation and provides a serial control signal to the oscillation section 9 according to this information. For example, television 5 at time 15:
When information to start operation is input to 00, the main control unit 8
When the time reaches 15:00, a control signal having an address indicating the television 5 is given to the excavation section 9 in order to start the operation of the television 5.

This excavation section 9 modulates the control signal with FSK and outputs it. Then, the FSK modulation signal output from the oscillation section 9 is amplified to a predetermined level by the amplifier 10 and supplied to the primary coil 12a of the transformer 12 in the output circuit 11, and thus the FSK modulation signal is transmitted from the secondary coil 12b to each capacitor c1. It is superimposed on the voltage waveform applied to the power line 1 through c2.

Then, the FSK modulated signal is transmitted to each receiving device 123-1 to 123-3.
-n, but it is not received by devices other than receiving device 3-2 because the addresses are different, and is received only by receiving device 3-2. As a result, from the receiving device 3-2 to the television 2
A control signal for starting the operation is sent to the television 5, and the television 5 starts operating.

However, because there are many electrical devices in the home, the electricity
A large number of receiving devices 3-1 to 3-n and electrical equipment are connected to 11. For this reason, the power line 1 seen from the controller 2
The line impedance of each receiving device 3-1 becomes smaller.
The amplitude level of the FSK modulated signal received by ~3-n becomes low, and the FSK modulated signal may not be received by each receiver [3-1 ~ 3-n]. In order to eliminate this phenomenon, it is possible to increase the amplification factor of the amplifier 10, but in this case, each electrical device in the home will not always be connected to the power line 1, and the electrical devices will be connected depending on whether or not they are used. Connection and disconnection are performed. Therefore, the line impedance changes each time, and is appropriate when the line impedance is low, but when the line impedance is high, the power loss increases. Also, FSK
The amplitude level of the modulation signal increases, causing noise to each electrical device.

(Problem to be solved by the invention) As described above, F received by each receiving device 3-1 to 3-n
If the amplitude level of the SK modulated signal becomes low, it will not be received,
Even if the amplification factor for the FSK modulated signal is increased, problems of power loss and noise occur.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a power line carrier transmitting/receiving device that can reliably transmit signals without being affected by the level of line impedance.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a power line in which a plurality of transmitting devices and receiving devices are connected to a power line, and a signal is transmitted by superimposing a signal on a voltage waveform applied to the power line at a predetermined carrier frequency. In a carrier transmitting/receiving device, a signal generator for superimposing an amplitude control signal of a constant amplitude level at a frequency close to a predetermined carrier frequency of the transmitting device on the voltage waveform of the power line is installed at the same position as the connection position of the transmitting device to the power line or The above object is achieved by including an amplitude level control means that detects an amplitude control signal at a position close to the connection position and variably controls the amplitude level of the carrier signal of the transmitter according to the amplitude level of the amplitude control signal. This is a power line carrier transmitting and receiving device.

(Function) By providing such means, an amplitude control signal of a constant level at a frequency close to the carrier frequency of the transmitting device is superimposed on the power line from the signal generator. At this time, the amplitude level control means detects the amplitude control signal at the same position as the connection position of the transmitting apparatus or at a position close thereto, and variably controls the amplitude level of the carrier signal of the transmitting apparatus in accordance with the amplitude level.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. Note that the same parts as in FIGS. 4 and 5 are given the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 1 is an overall configuration diagram of a home controller to which a power line carrier transmitter/receiver is applied. The signal generator 20 generates a frequency close to the carrier frequency of the controller 21, for example, if the carrier frequency of the controller 21 is 120kHz, the signal generator 20 generates a frequency of 100kHz.
H or 135kHz, 150k) (if 170kHz and a constant level of amplitude), it has the function of superimposing an amplitude control signal with a constant level of amplitude on the voltage waveform of the power line 1, and the farthest position of the power line 1 as seen from the controller 21. The specific configuration includes an oscillator 22 that emits an amplitude control signal as shown in FIG. 23 secondary coils 23b are connected to the plug outlet 2.4 through capacitors C3 and C4.

On the other hand, the controller 21 includes an amplitude level control means that detects the amplitude control signal superimposed on the voltage waveform applied to the power line 1 and variably controls the amplitude level of the carrier signal according to the amplitude level. It is being The specific configuration is shown in Figure 3. secondary coil 30a,
A transformer 32 having a secondary coil 30b and a secondary coil 31 is provided, and an amplitude detector 33 constituting amplitude level control means is connected to the primary coil 30a. This amplitude detector 33 discriminates the amplitude control signal through the primary coil 30a using a frequency discrimination function, judges the amplitude level of this amplitude control signal, and sends a DC voltage signal corresponding to the amplitude level to the variable resistance element 35. It has a function to send data to. Note that a PLL circuit is used as the frequency discrimination function.

On the other hand, the output terminal of the oscillator 9 is connected via a resistor R1 to the operational amplifier 34 which constitutes the amplitude level tlIlI11 means.
” side input terminal is connected. The variable resistance element 35 is connected to the feedback loop of the operational amplifier 34. This variable resistance element 35 receives a DC voltage signal, and its resistance value decreases when the voltage level of this signal is high, and conversely, the resistance value changes greatly when the voltage level is low.

Next, the operation of the apparatus configured as described above will be explained. At all times, the oscillator 22 of the signal generator 20 has an amplitude of 1111 J.
The primary coil 23 of the transformer 23 oscillates the fll signal.
Therefore, the amplitude control signal is superimposed on the voltage waveform applied to the power line 1 through the transformer 23. On the other hand, the controller 21 detects the amplitude control signal by frequency discrimination using the amplitude detector 33 through the primary coil 30a of the transformer 32. Incidentally, the amplitude level of the amplitude control signal varies according to a change in the impedance between A and A of the power line 1. The line impedance changes as each electrical device is connected to and disconnected from the power line 1. Therefore, the amplitude level of the amplitude control signal detected by the amplitude detector 33 reflects the line impedance. Thus, the amplitude detector 33 determines the amplitude level of the amplitude control signal and sends a DC voltage signal corresponding to this amplitude level to the variable resistance element 35, so that the variable resistance element 35 detects the voltage level of the DC voltage signal. The resistance value is variably controlled according to the

In this state, for example, set the television 5 to time 1 in the same way as above.
When the information to start operation at 5:00 is input to the operation unit 8 and the time is: oo, the oscillator 9 sends a 1IIJ Ill signal containing the start of operation of the television 5 and the address of the television 5 under the control of the control unit 8. is FSK
It is modulated and sent out. This FSK modulation signal is then amplified by the operational amplifier 34 with an amplification factor corresponding to the resistance value of the variable resistance element 35, applied to the secondary coil 301), and superimposed on the voltage waveform of the power line 1 through the transformer 32. Ru.

As a result, the amplitude level of the FSK modulated signal is controlled to a constant amplitude level no matter what value the inter-line impedance value changes, and is at a level that can be received by all receiving devices 3-1 to 3-n. In this case, the FSKf tone signal is received only by the receiving device 3-2, and the television 5 starts operating by the receiving device 3-2.

In this way, in the above embodiment, an amplitude control signal of a constant level is superimposed on the power line 1 from the signal generator 20 at a frequency close to the carrier frequency of the controller 21, and at this time, the amplitude control signal is controlled by the amplitude level control means. Since the amplitude level of the carrier signal of the controller 21 is variably controlled according to the amplitude level of the controller 21, even if the line-to-line impedance of the power line changes due to the connection and disconnection of each electrical device, each receiving device 3-1 to 3-3 is always connected. An FSK modulation signal having an amplitude level that can be received at -n can be superimposed on a voltage waveform, and noise is not imparted to each electrical device with minimum power loss.

In particular, since an amplitude control signal having a frequency close to the carrier frequency is used, line-to-line impedance changes approximate to the transmission characteristics of the FSK modulated signal, and more accurate amplitude control is possible. Moreover, since the signal generator 20 is connected to the farthest position from the controller 21, the signal generator 20 is connected to the receiving device 3-1.
Reliable reception is possible at ~3-n.

Note that the present invention is not limited to the above-mentioned embodiment, and may be modified without departing from the spirit thereof. For example, the amplitude level control means may not be located in the controller 21, but may be connected to the power line 1 in the vicinity of the controller 21 to variably control the amplitude level of the controller 21. Alternatively, the amplitude control signal may be detected, A/D converted, and then amplitude controlled by a microcomputer.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide a power line carrier transmitting/receiving device that can reliably transmit signals without being affected by the level of inter-line impedance.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a home controller to which a power line carrier transmitting/receiving device according to the present invention is applied, and FIG. 2 is a configuration diagram of a signal generator in the device of the present invention. 1... Power line, 3-1 to 3-n... Receiving device, 4.
...lighting, 5...television, 6...refrigerator,
2o...signal generator, 21...controller, 22
...Oscillator, 23...Transformer, 30a...First
-Second coil, 30b...Second coil, 31...
Secondary coil, 32...Transformer, 33...Amplitude detector, 34...Operation amplifier, 35...Variable resistance element. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a power line carrier transmitting/receiving device that connects a plurality of transmitting devices and receiving devices to a power line and transmits a signal by superimposing a signal on a voltage waveform applied to the power line at a predetermined carrier frequency, the frequency is constant at a frequency close to the predetermined carrier frequency of the transmitting device. a signal generator that superimposes an amplitude control signal of an amplitude level on the voltage waveform of the power line; and a signal generator that detects the amplitude control signal at the same position as the connection position of the transmitter to the power line or at a position close to this connection position. A power line carrier transmitting/receiving device comprising: amplitude level control means for variably controlling the amplitude level of a carrier signal of the transmitting device according to the amplitude level of an amplitude control signal of a lever.