JP2006174181A - Modem for power line communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a transmission loss of a power line communication signal, and make it easy to acquire approval of safety specifications of a modem used as a load. <P>SOLUTION: The modem is provided with a voltage conversion means 11 which converts voltage of a commercial power line to AC voltage or DC voltage which is lower voltage than the source, and supplies to the modem 20; a transformer for signal transmission 12; two input terminals 10a, 10b which input the commercial power line voltage; and two output terminals 10c, 10d which output the AC voltage or the DC voltage of lower voltage; connects the input side of the voltage conversion means 11 to the input terminals 10a, 10b through a 1st high impedance means 13, 13; connects the output side to the output terminals 10c, 10d through a 2nd high impedance means 14, 14; connects a primary winding of the signal transmission transformer 12 to the input terminals 10a, 10b; and connects the secondary winding to the output terminals 10c, 10d. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power supply device for supplying power to a modem device that performs communication using a power line.

  A conventional power supply device for a power line communication device will be described with reference to FIG. The output terminals t3 and t4 of the input circuit unit 5 and the input terminals t5 and t6 of the output circuit unit 6 are connected to the power line connection terminals 1 and 2, and a device selection input is externally input to the input terminal t0 of the input circuit unit 5. Data DA is input. Output terminals t9 and t10 of the output circuit unit 6 are connected to a control unit (not shown). The control unit takes in control data of a pulse-modulated digital signal output from the output circuit unit 6, and is connected to a power line. The switching operation control data is output to a switch (not shown) that controls on / off of the input power source of the electrical device (not shown).

  That is, when the device selection input data DA is input to the input circuit 5 from the outside, the data is converted into a pulse-modulated digital signal of 30 to 70 KHz, and is transmitted over the commercial power supply 100V. The digital signal is input to the output circuit 6 and output to the control unit as control data.

  An AC terminal of a power supply rectifier 52 is connected to the primary coil of the transformer 50, a voltage regulator is connected to one end of the DC terminal, and a pulse modulation circuit 55 is connected to the output side thereof. A complementary transistor circuit (Q1 / Q2) is connected to the output side of the pulse modulation circuit 55, and its input power supply terminal and output power supply terminal are connected to the DC terminal of the voltage regulator 52. A voltage / current obtained by amplifying the input signal via the capacitor 58 is output to the power line via the transformer 51 on the output side of the complementary circuit. One end of the primary coil of the transformer 51 and the common end of the voltage regulator 54 and the pulse modulation circuit 55 are connected to the DC terminal of the power supply rectifier 52, and the secondary coil of the transformer 51 is connected between the power lines via the capacitor C1. The In other words, when the device selection data DA is input from the outside to the input circuit unit 5, it is converted into a pulse-modulated digital signal and transmitted by being superimposed on a commercial power supply via the transformer 51.

  A power supply rectifier circuit 62 is connected to the secondary coil of the transformer 61, and its DC output is connected to an output amplifier 66, a band pass filter 67 having a resistor 68, and a power input / output terminal of the detector circuit 69. The transformer 60 has a primary coil connected between the power lines via the capacitor C 2, one end of the secondary coil connected to the input end of the output amplifier 66 via the capacitor 63, and the output end connected to the band pass filter 67. The output terminal is connected to the input terminal of the detection circuit 69. Then, the output terminal of the detection circuit 69 is output to a subsequent control unit (not shown) via a terminal t0 (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 08-056386 (FIG. 2)

  In the configuration of the conventional example, signals flowing in the signal transmission transformers 51 and 60 also flow in the power supply transformers 50 and 61 and the power supply rectifier circuits 52 and 62, respectively. In addition, when obtaining certification of safety standards for such a power supply device, AC100V is wired to the input circuit unit 5 and the output circuit unit 6, so when changing the configuration of the secondary side of the power supply unit However, it was necessary to obtain certification each time including the primary side of the power supply, and the certification procedure was complicated.

  The present invention makes it easy to obtain safety standard certification of a modem device by causing a power line communication signal to flow through a power transformer or a rectifier circuit without causing a signal loss and by reducing the voltage supplied to the modem device. Objective.

  As a first solution to the above problems, voltage conversion means for converting the voltage of the commercial power supply line into a lower AC voltage or DC voltage lower than that and supplying the converted voltage to the modem device, the signal transmission transformer, A first high-impedance unit having two input terminals to which a voltage of a commercial power supply line is input and two output terminals from which the low-voltage AC voltage or DC voltage is output; The output side of the voltage conversion circuit is connected to the output end via a second high impedance means, and the primary winding of the signal transmission transformer is coupled to the input end. The secondary winding of the signal transmission transformer is coupled to the output end.

  Further, as a second solving means, the voltage conversion circuit has a step-down power transformer, a primary winding of the step-down power transformer is connected to the input terminal via the first high impedance means, The secondary winding of the step-down power transformer is connected to the output terminal via the second high impedance means.

  As a third solution, the voltage conversion circuit includes a step-down power transformer and a rectifier circuit, and a primary winding of the step-down power transformer is connected to the input terminal via the first high impedance means. The secondary winding of the step-down power transformer is connected to the AC input terminal of the rectifier circuit, and the DC output terminal of the rectifier circuit is connected to the output terminal via the second high impedance means.

  As a fourth solution, the number ratio of the primary winding to the secondary winding in the signal transmission transformer is set to 1: 1.

  As a fifth solution, a cord with a plug is connected to the input end, and a cord with a connector is connected to the output end.

  According to the first solution means, the voltage conversion means for converting the voltage of the commercial power supply line into a lower AC voltage or DC voltage lower than that and supplying the converted voltage to the modem device, the signal transmission transformer, and the commercial power supply line The input terminal of the voltage conversion means is connected to the input terminal via the first high impedance means. Connected to the output terminal via the second high impedance means, the primary winding of the signal transmission transformer is coupled to the input terminal, and the secondary winding is coupled to the output terminal. The transmission loss of the power line communication signal is suppressed, and the certification of the safety standard of the modem device is easily obtained.

  Further, according to the second solution means, the voltage conversion circuit has the step-down power transformer, the primary winding of the step-down power transformer is connected to the input terminal via the first high impedance means, and the step-down power supply Since the secondary winding of the transformer is connected to the output end via the second high impedance means, the power line communication signal is transmitted through the signal transmission transformer without being input to the power transformer.

  According to the third solution means, the voltage conversion circuit has a step-down power transformer and a rectifier circuit, and the primary winding of the step-down power transformer is connected to the input terminal via the first high impedance means. Since the secondary winding of the step-down power transformer is connected to the AC input terminal of the rectifier circuit and the DC output terminal of the rectifier circuit is connected to the output terminal via the second high impedance means, the power line communication signal is transmitted to the power transformer. The signal is transmitted through a signal transmission transformer without being input to the rectifier circuit.

  According to the fourth solution, since the number ratio of the primary winding to the secondary winding in the signal transmission transformer is 1: 1, the loss of the power line communication signal is constant between reception and transmission. It becomes.

  Further, according to the fifth solution, since the cord with the plug is connected to the input end and the cord with the connector is connected to the output end, the power supply itself can be certified as a safety standard, and can be used for various modem devices. Can be used in common.

  FIG. 1 shows a first embodiment of a power supply apparatus (hereinafter referred to as a power supply apparatus) for a power line communication modem according to the present invention together with a modem apparatus. In FIG. 1, the power supply device 10 includes voltage conversion means 11 and a first signal transmission transformer 12. The voltage conversion means 11 is composed of a step-down power supply transformer 11a. The secondary voltage of the power transformer 11a is a low voltage of about 10 volts, for example. The turn ratio of the primary winding and the secondary winding of the first signal transmission transformer 12 is 1: 1. The primary winding of the power transformer 11a is connected to the input terminals 10a and 10b via the first high impedance means 13 and 13. The secondary winding is connected to the output terminals 10c and 10d via the second high impedance means 14 and 14. The first and second high impedance means 13 and 14 are constituted by choke inductors or the like.

  The primary winding of the first signal transmission transformer 12 is coupled to the input terminals 10 a and 10 b via the capacitor 15, and the secondary winding is coupled to the output terminals 10 c and 10 d via the capacitor 16.

  The input terminals 10a and 10b are connected to an AC cord 17 with a plug 17a, and the output terminals 10c and 10d are connected to a coaxial line 18 with a connector 18a.

  The modem device 20 includes a first rectifier circuit 21, a second signal transmission transformer 22, and a modem circuit 23. The turn ratio of the primary winding and the secondary winding of the second signal transmission transformer 22 is 1: 1. The AC input terminal of the first rectifier circuit 21 is connected to a connector 25 constituting an input terminal via third high impedance means 24 and 24. The third high impedance means 24 is also composed of a choke inductor or the like. A plurality of types of DC voltages of 10 volts or less output from the first rectifier circuit 21 are supplied to the modem circuit 23.

  The primary winding of the second signal transmission transformer 22 is coupled to the connector 25 via the capacitor 26, and the secondary winding is coupled to the modem circuit 23 via the capacitor 27. An information processing terminal device such as a personal computer (PC) is coupled to the modem circuit 23.

  In the above configuration, when the AC cord 17 is connected to the commercial power line, the modem device 20 is supplied with a low voltage of AC 10 volts, and a DC voltage is output from the first rectifier circuit 21 to drive the modem circuit 23. . At this time, in the power supply device 10, the power line communication signal superimposed on the commercial power supply line is inserted with the first high impedance means 13 and 13 on the input side of the voltage conversion means 11 (power supply transformer 11a). Therefore, it is not input to the voltage conversion means 11 but is output to the coaxial line 18 via the first signal transmission transformer 12. That is, the power line communication signal is superimposed on AC 10 volts on the coaxial line 18. At this time, the power line communication signal appearing at the output terminals 10 c and 10 d is not input to the voltage conversion means 11 due to the intervention of the second high impedance means 14 and 14.

  The low voltage of AC 10 volts is input to the first rectifier circuit 21, but the power line communication signal is not input to the first rectifier circuit 21 due to the third high impedances 24 and 24, and the second signal transmission is performed. The signal is input to the modem circuit 23 via the transformer 22. For this reason, the loss of the power line communication signal in the power supply device 10 is minimized.

  Conversely, the power line communication signal input from the information processing terminal device to the modem circuit 23 passes through the second signal transmission transformer 22, the coaxial line 18, the first signal transmission transformer 12, and the AC cord 17, and the commercial power line. Is output. Also in this case, the transmission loss of the power line communication signal is suppressed to the minimum for the same reason.

  Also, if the power supply device 10 itself has been certified as a safety standard, the modem device 20 used in combination with the power supply device 10 has a low supplied voltage. Certification is easy to obtain.

  FIG. 2 shows a second embodiment. In FIG. 2, the same components as those in FIG. In FIG. 2, the voltage conversion means 11 has a step-down power transformer 11a and a second rectifier circuit 11b, and the secondary winding of the power transformer 11a is connected to the AC input terminal of the second rectifier circuit 11b. . For example, the second rectifier circuit 11b outputs a low voltage of DC 10 volts to the DC output terminal. Therefore, the power line communication signal is superimposed on DC 10 volts on the coaxial line 18.

  In the modem device 20, a DC-DC converter 28 is used instead of the first rectifier circuit 21 shown in FIG. The DC-DC converter outputs a plurality of types of DC voltages and supplies them to the modem circuit 23.

1 is a circuit diagram showing a configuration of a first embodiment of a power supply device for a power line communication modem of the present invention. FIG. It is a circuit diagram which shows the structure of 2nd Embodiment in the power supply device of the modem for power line communication of this invention. It is a circuit diagram which shows the structure of the power supply device of the conventional modem for power line communication.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Power supply device of power line communication modem 10a, 10b: Input terminal 10c, 10d: Output terminal 11: Voltage conversion circuit 11a: Power transformer 11b: Second rectifier circuit 12: First signal transmission transformer 13: First High impedance means 14: Second high impedance means 15, 16: Capacitor 17: AC cord 17a: Plug 18: Coaxial line 20: Modem device 21: First rectifier circuit 22: Second signal transmission transformer 23: Modem circuit 24: third high impedance means 25: connector 26, 27: capacitor

Claims (5)

Voltage conversion means for converting the voltage of the commercial power line into a lower AC voltage or DC voltage lower than that, and supplying the converted voltage to the modem device; a signal transmission transformer; and two voltages to which the voltage of the commercial power line is input An input end, and two output ends from which the low-voltage AC voltage or DC voltage is output, the input side of the voltage conversion means is connected to the input end via a first high impedance means, and The output side of the voltage conversion circuit is connected to the output end via a second high impedance means, the primary winding of the signal transmission transformer is coupled to the input end, and the secondary winding of the signal transmission transformer A power supply device for a power line communication modem device, wherein The voltage conversion circuit includes a step-down power transformer, a primary winding of the step-down power transformer is connected to the input terminal via the first high impedance means, and a secondary winding of the step-down power transformer 2. The power supply device for a power line communication modem device according to claim 1, wherein the power supply device is connected to the output terminal via the second high impedance means. The voltage conversion circuit includes a step-down power transformer and a rectifier circuit, and a primary winding of the step-down power transformer is connected to the input terminal via the first high impedance means. The secondary winding is connected to an AC input terminal of the rectifier circuit, and a DC output terminal of the rectifier circuit is connected to the output terminal via the second high impedance means. Power line communication power supply modem device. 4. The power supply device for a power line communication modem device according to claim 1, wherein the number ratio of the primary winding and the secondary winding in the signal transmission transformer is 1: 1. 5. The power supply device for a power line communication modem device according to claim 4, wherein a cord with a plug is connected to the input end, and a cord with a connector is connected to the output end.

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