JPS6328535B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a transmitting/receiving device, and more particularly to a transmitting/receiving device suitable for transmitting an information signal by superimposing it on a power supply line.

Configurations of conventional examples and their problems The following conventional examples are closest to the present invention. This connects the transmitter and receiver with two lines, supplies power from one to the other, and superimposes a signal on the line to transmit information. The power supply and line are connected via a signal leak prevention element (reduction filter), and signal superimposition and separation are performed via a tuning transformer connected in parallel to the line, achieving frequency selectivity. It has a circuit configuration. This tuning transformer is provided separately for transmission and reception.

Problems with such a configuration are as follows. That is, in the transmission operation, a logic "1" state drives the tuning transformer at the carrier frequency and superimposes a carrier wave on the line, and a logic "0" state causes the so-called tone by stopping the tuning transformer drive. It is constructed using a burst method, but immediately after the signal switches from logic "1" to logic "0", a parallel resonant circuit consisting of a tuning transformer and a tuning capacitor connected in parallel with it is activated. , the vibrational energy (1/2CV ²
+1/2Li ² ) remains, and as shown in FIG. 4b, a phenomenon occurs in which the vibration of the resonant circuit continues for a while (time ta) even in the time domain of logic "0".

This means that when the signal is demodulated on the receiving side, the logic "1" state will invade the logic "0" time domain, as shown in Figure 4c, and the time tb will be A larger value means that the reception of the information signal becomes uncertain. still,
Figure 4a is the original information.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a transmitting/receiving device capable of reliably transmitting logic "1" and logic "0" with a simple configuration and eliminating the above-mentioned drawbacks.

Structure of the Invention The present invention connects a secondary winding of a tuned transformer to a power supply line for supplying power from one of at least one pair of transmitting/receiving devices to the other, and connects the secondary winding of the tuned transformer to the power supply line. a switch means for short-circuiting the parallel resonant circuit formed by the primary winding of the tuning transformer and the tuning capacitor; is provided, and when the information signal changes from logic "1" to logic "0", the switch means is turned on to instantaneously consume the vibration energy stored in the parallel resonant circuit, and the logic "1" and logic "0" are changed. This is to accurately transmit the 0'' delimiter.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention is shown in FIGS. 1A and 1B. 1st
Figure A is connected to a commercial power supply AC100V, etc.
FIG. 1B shows a transmitting/receiving device that has power supply capability and supplies power to other transmitting/receiving devices, and conversely, FIG. 1B shows a transmitting/receiving device that receives power.

In FIG. 1A, 1 indicates the entire configuration of the transmitting/receiving device on the power supply side, and through terminals 2a and 2b,
Connected to commercial power supply AC100V. 3 is the power supply circuit I, which converts the AC100V input into the DC voltage necessary for electronic circuit operation, such as +12V, +5V, etc., or converts it into a power supply _VB for transmission to the transmitting/receiving device on the power receiver side. It is something to do.

Terminals 4a and 4b connect lines 5a and 5b,
It is used to supply power to other transmitting/receiving devices and to transmit/receive information signals, and is connected to both ends 7a, 7b of the power source _VB via a secondary winding 6a of a transformer 6 inserted in series. Both ends of power supply V _B 7
A capacitor 8 connected in parallel to a and 7b is used together with the transformer 6 to separate the power supply _VB and the information signal.

That is, the capacitance c of the capacitor 8, the transformer 6
By setting the equivalent inductance L seen from the secondary winding side of the coil to an appropriate value, the respective impedances z with respect to the frequency f can be made to have the characteristics as shown in FIG. Now, the frequency of power supply V _B is
f ₁ and the frequency of the information signal is f ₂ , Z _C ≫ Z _L at frequency f ₁ and Z _L ≫ Z _C at frequency f _{2 .}
According to the well-known electric circuit principle, only the information signal component appears at both ends of the secondary winding 6b of the transformer 6.
This separates _VB from the information signal.

Further, by connecting a tuning capacitor 9 in parallel with the primary winding 6a of the transformer 6 to configure a tuning transformer 10 having a parallel resonant circuit 10a, information signals to be transmitted and received have frequency selection characteristics. Therefore, the electromagnetic noise radiated to the outside through the lines 5a and 5b need only be considered at the resonant frequency, and conversely, the same reason can be applied to the electromagnetic noise that enters from the outside. The parallel resonant circuit 10a has the advantage that it has a very strong ability to eliminate noise at frequencies other than the resonant frequency, and can reduce information transmission errors. There is a problem in that the vibrational energy stored in the information signal causes inaccurate data delimitation when the information signal transitions from logic "1" to logic "0".

Therefore, in the present invention, a switch means 11 is connected in parallel to the parallel resonant circuit 10a, and when the information signal changes from logic "1" to logic "0", the switch means 11 short-circuits the parallel resonant circuit 10a. , the purpose is to instantly eliminate the accumulated vibrational energy, accurately delimit logic "1" and logic "0", and transmit information signals. In the switch means 11, 11a is a FET transistor, which directly short-circuits the parallel resonant circuit 10a. 11b is a current limiting resistor connected in series with the FET transistor 11a. 11c is FET
This is a drive circuit for the transistor 11a, and is output from the OUT terminal of the transmission/reception logic circuit 15.
By the CLAMP signal, FET transistor 11
Turn a on and off.

Further, a modulation circuit 12 and a demodulation circuit 13 are connected to both ends of the primary winding 6a of the transformer 6, and +5V is connected to the intermediate tap.

The modulation circuit 12 includes a transmission/reception logic circuit 14.
The information signal DATA output from the OUT1 terminal is input, and after being modulated by a carrier wave oscillating section 12a configured with a CMOS NAND gate, etc., it is modulated by a tuning transformer 1 by a driving section 12b configured with a transistor, etc.
It drives 0.

The information signal frequency-selected by the tuned transformer 10 is passed through the line 5 through the secondary winding 6b of the transformer 6.
a, 5b, and transmitted to other transmitting/receiving devices 16.

Conversely, the information signals transmitted from other transmitting/receiving devices via the lines 5a and 5b are generated at both ends of the secondary winding of the transformer 6, and only the information signals having frequency components that resonate with the parallel resonant circuit 10a are transmitted. It appears on the primary winding 6a side. This information signal is transmitted to the demodulation circuit 1
After performing pre-processing such as impedance conversion and amplification in the input processing section 13a of 3, the detection section 13b performs AM
Detected. Next, after being shaped into a digital pulse by the waveform shaping section 13c, the transmitting/receiving logic circuit 14
Input from the IN terminal.

In this way, the configuration is simple in that only one transformer 6 is used to superimpose/separate information signals and perform transmission/reception operations.

Reference numeral 15 denotes an input/output circuit consisting of LEDs, keys, switches, relays, volumes, sensors, etc., and the input/output information is exchanged with other far away transmitting/receiving logic circuits 16 via the transmitting/receiving logic circuit 14. This is what is communicated to. Note that it is preferable to use a microcomputer for the transmission/reception logic circuit 14.

Next, in FIG. 1B, reference numeral 16 indicates the overall configuration of the transmitting/receiving device on the power receiving side. Terminals 17a, 17b
Lines 5a and 5b are connected to the terminals, and transmitted power and information signals are input and output. Reference numeral 18 denotes a diode bridge, which makes the connections between terminals 17a and 17b and lines 5a and 5b non-polarized and provides fixed polarity to the power supply circuit 19, regardless of whether the transmitted power is direct current or alternating current. It supplies DC voltage V _C.

The method of separating the power supply and information signal is as explained in FIG. 1A, and the power supply V _C appearing across the capacitor 8 is connected to
It converts it into a stabilized DC voltage such as 12V or +5V, and operates the entire transmitting/receiving device 16 on the power receiving side.

Since the other circuit blocks are exactly the same as those explained in FIG. 1A, their explanation will be omitted.
Note that the same numbers are used for the same functional blocks.

With the above configuration, the transmission and reception operations as shown in FIG. 3 can be obtained. That is, FIG. 3a shows the information signal DATA output from the transmitting/receiving logic circuit 14 of one of the transmitting/receiving devices (1 or 16), and FIG.
It is a CLAMP signal. With DATA signal like this
Depending on the timing of the CLAMP signal, lines 5a,
5b, it is possible to send out an information signal with accurate delimitation between logic "1" and logic "0" as shown in FIG. Figure d shows such an information signal demodulated by the other transmitter/receiver (16 or 1), in which logic "1" and logic "0" are faithfully transmitted. In the circuit of the embodiment, the output signal of the demodulation circuit 13 is an inversion of the signal d in the figure.

In addition, during reception operation, the CLAMP signal is logic "1" and the FET transistor 11a is off.
During transmission operation, when the DATA signal is logic "1", the FET transistor 11a is turned off, and when the DATA signal is logic "0", the FET transistor 11a is turned off.
In this case, the FET transistor 11a is turned on.

Effects of the Invention As is clear from the above detailed description, the present invention connects the secondary winding of a tuned transformer to a power supply line for supplying power from one of at least one pair of transmitting/receiving devices to the other. A parallel resonant circuit formed by the primary winding of the tuned transformer and the tuned capacitor, which superimposes the information signal on the power supply line or, conversely, separates the information signal from the power supply line in a selected frequency band. A switch means for short-circuiting the parallel resonant circuit is provided in parallel with the information signal, and the switch means is turned on when the information signal is logic "0", and when the information signal is logic "1", the information signal is stored in the parallel resonant circuit. Since the vibration energy generated by the transmission is instantaneously consumed, it is possible to transmit an information signal with an accurate delimitation between logic "1" and logic "0", and a highly reliable transmitting/receiving device can be realized.

[Brief explanation of the drawing]

Figures 1A and B are circuit configuration diagrams showing a transmitting and receiving device according to an embodiment of the present invention, Figure 2 is a circuit characteristic diagram showing the principle of signal separation, and Figures 3a, b, c, and d are the same circuits. Timing diagram of some signal waveforms representing operation, Part 4
Figures a, b, and c are timing diagrams of some signal waveforms representing circuit operations in a conventional example. 1... Transmitting/receiving device (power supply side), 5a, 5b
...Line, 6...Transformer, 6a...Transformer primary winding, 6b...Transformer secondary winding, 8...Capacitor (for signal separation), 9...Tuning capacitor,
10... Tuning transformer, 10a... Parallel resonant circuit, 16... Transmitting/receiving device (power receiving side).

Claims (1)

[Claims] 1. A parallel resonant circuit is constructed by connecting a primary winding and a tuning capacitor in parallel, and a tuning transformer in which a secondary winding is connected to a power supply line is used to transmit information on the power supply line. A transmitting/receiving device that superimposes signals, performs information transmission and power supply on the same line, and is provided with a switch means for short-circuiting the parallel resonant circuit in parallel. 2. The switch means is turned off when the information signal is at logic "1" during transmission, that is, when the tuning transformer is being driven, and is turned on when the information signal is at logic "0", that is, when it is not driven. Transmitting/receiving device as described.