JP5879400B1 - Control system - Google Patents

Abstract

A control system for transmitting a signal to a load device via a power line without hindering normal operation of the load device. A control system includes a controller and a load device including an operation unit. The controller 1 supplies AC power to the load device 2 through the power line 4 to operate the operation unit 5. Moreover, the transmission part 6 is provided. The transmission unit 6 transmits a control signal to the load device 2 via the power line 4 by reducing the voltage supplied to the load device 2 in a pulse shape without making it zero except at the zero cross point of the AC waveform. The load device 2 includes a demodulation unit 7 and a control unit 8. [Selection] Figure 1

Description

  The present invention relates to a control system in which a controller and a load device are connected via a power line.

  Patent Document 1 describes a control system in which a controller and a load device are connected via a power line. In the control system described in Patent Document 1, power is supplied from the controller to the load device via the power line. In this control system, power supplied from the controller to the load device is cut off for an extremely short time, and a signal is transmitted from the controller to the load device via the power line.

Japanese translation of PCT publication No. 2004-508796

  In the control system described in Patent Document 1, when a signal is transmitted from the controller to the load device, the supply of power is cut off for a short time. For this reason, depending on the type of load, normal operation may be hindered when a signal is being transmitted. For example, when the signal is transmitted, the operation speed of the load device may become irregular or abnormal noise may occur.

  The present invention has been made to solve the above-described problems. The objective of this invention is providing the control system which can transmit a signal to a load apparatus via a power line, without preventing normal operation | movement of a load apparatus.

A control system according to the present invention includes a load device including an operation unit, and a controller that supplies AC power to the load device via a power line to operate the operation unit, and the controller supplies the load device. voltage by Do things ku low to zero except zero-crossing point of the AC waveform, and transmitting means for transmitting the control signal to the load device via a power line, a load device, received from the controller Demodulating means for demodulating the control signal, and control means for controlling the operating unit based on the result demodulated by the demodulating means. The controller further includes a first AC output terminal and a second AC output terminal connected to the power line, the first AC output terminal is connected to the first terminal of the AC power source, and the transmission means has a drain having the second AC output. A field effect transistor connected to the terminal and having a source connected to the second terminal of the AC power supply; and a diode connected between the gate and drain of the field effect transistor.

  With the control system according to the present invention, a signal can be transmitted to the load device via the power line without disturbing the normal operation of the load device.

It is a figure which shows the structure of the control system in Embodiment 1 of this invention. It is a figure which shows the specific example of the control system in Embodiment 1 of this invention. It is a figure which shows the specific example of the control system in Embodiment 1 of this invention. It is a time chart at the time of the modulation | alteration of the control system in Embodiment 1 of this invention. It is a figure which shows the example of application of the control system in Embodiment 1 of this invention. It is a flowchart which shows operation | movement of a controller. It is a flowchart which shows operation | movement of a LED lamp.

  The present invention will be described with reference to the accompanying drawings. The overlapping description will be simplified or omitted as appropriate. In each figure, the same reference numerals indicate the same or corresponding parts.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a control system in Embodiment 1 of the present invention.
The control system includes a controller 1 and a load device 2. An AC power supply 3 is connected to the controller 1. The AC power supply 3 supplies AC power to the controller 1. The controller 1 and the load device 2 are connected by a power line 4. The controller 1 supplies AC power to the load device 2 through the power line 4.

  The load device 2 includes an operation unit 5. In the load device 2, when the AC power is supplied from the controller 1, the operation unit 5 performs a predetermined operation. The operation performed by the operation unit 5 may be one that accompanies displacement of a component, such as a motor, or one that does not accompany displacement of a component. Examples of operations that do not involve displacement of components include light emission, heat generation, and sound generation. In addition, the operation | movement which the operation | movement part 5 performs is not limited to these.

  The controller 1 includes a transmission unit 6. The transmission unit 6 transmits a control signal to the load device 2 via the power line 4. The transmission unit 6 transmits a control signal to the load device 2 by reducing the voltage supplied to the load device 2 in a pulse shape. The transmission unit 6 reduces the voltage supplied to the load device 2 when transmitting the control signal in a pulsed manner without making it zero other than the zero cross point of the AC waveform. The control signal includes, for example, information for changing the operation of the operation unit 5.

The load device 2 includes a demodulation unit 7 and a control unit 8.
The demodulator 7 demodulates the control signal received from the controller 1 by the load device 2. The demodulator 7 demodulates the control signal based on the voltage drop pattern supplied from the controller 1. For example, the demodulator 7 monitors a temporal change in the AC voltage supplied from the controller 1 and demodulates the control signal based on the change.

  The control unit 8 controls the operation of the operation unit 5. Based on the result demodulated by the demodulator 7, the controller 8 controls the operation unit 5 so that the operation unit 5 operates according to the information included in the control signal.

  Next, a specific example of the present control system will be described with reference to FIGS. The present control system can be applied to various industrial and household systems as long as the controller 1 and the load device 2 are connected via the power line 4. The load device 2 may be a home appliance, for example. If this control system is applied, the home appliance can be remotely controlled without connecting a dedicated signal line between the controller 1 and the home appliance (load device 2).

  In the following, the control system will be described by taking as an example a case where an LED (light emitting diode) lamp is employed as the load device 2. This control system is preferably applied to, for example, a lighting system employed in offices, factories, and mass sales stores. In addition, the application example of this control system is not limited to this.

  2 and 3 are diagrams showing a specific example of the control system according to Embodiment 1 of the present invention. FIG. 2 shows a circuit diagram of the controller 1a. The controller 1a is an example of the controller 1 shown in FIG. FIG. 3 shows a circuit diagram of the LED lamp 2a. The LED lamp 2a is an example of the load device 2 shown in FIG. The controller 1a and the LED lamp 2a are connected by a power line 4. The controller 1 a supplies AC power to the LED lamp 2 a through the power line 4. In addition, the controller 1a transmits a control signal to the LED lamp 2a via the power line 4.

  In FIG. 2, AC indicates an AC power supply for supplying AC power to the controller 1a. Vac is the voltage of the AC power supply AC. ZL indicates the LED lamp 2a connected to the controller 1a via the power line 4.

  As shown in FIG. 2, the controller 1a includes a microprocessor U1, resistors R1 to R7, capacitors C1 and C2, diodes D1 to D5, Zener diodes (constant voltage diodes) ZD1 to ZD3, a field effect transistor Q1, and a bipolar transistor Q2. , Operation panel OP. P and AC output terminals ZL_H and ZL_C are provided. Various operations of the controller 1a are controlled by the microprocessor U1. The power line 4 is connected to the AC output terminals ZL_H and ZL_C.

  D, G, and S shown in FIG. 2 are the drain, gate, and source of the field effect transistor Q1. Vcc in FIG. 2 indicates the power supply voltage of the microprocessor U1. VL represents a voltage between the AC output terminals ZL_H and ZL_C. VB, Vd, and Vg indicate voltages at respective points in the circuit shown in FIG. P_Tx is a pulse train transmitted as a control signal.

  1 is realized by the microprocessor U1, the diode D1, the Zener diode ZD1, and the field effect transistor Q1. Means for realizing the function of the transmission unit 6 is not limited to these. If the voltage supplied to the load device 2 can be reduced to a pulse without making it zero other than the zero crossing point of the AC waveform, some or all of the functions of the transmitter 6 can be realized by other software or hardware. May be.

  As shown in FIG. 3, the LED lamp 2a includes a microprocessor U1, resistors R1 and R2, capacitors C1 and C2, a rectifier (full wave rectifier) BD1, an LED module (LED MODULE), and AC input terminals ZL_H and ZL_C. . Various operations of the LED lamp 2a are controlled by the microprocessor U1. The power line 4 is connected to the AC input terminals ZL_H and ZL_C.

  Vcc in FIG. 3 indicates the power supply voltage of the microprocessor U1. Dmg PWM is a pulse width modulation signal.

  The principal part of the function which each part of the load apparatus 2 shown in FIG. 1 has is implement | achieved by the rectifier BD1 and the microprocessor U1. Means for realizing the function of each part of the load device 2 is not limited to these. You may implement | achieve part or all of the function which each part of the load apparatus 2 has with other software or hardware.

  FIG. 4 is a time chart during modulation of the control system according to the first embodiment of the present invention. FIG. 4A shows the waveform of the voltage Vac of the AC power supply AC. (A) shown in the circuit of FIG. 2 corresponds to (a) of FIG. The same applies to (b) to (e) shown in the circuit of FIG. 2 and (f) to (g) shown in the circuit of FIG. PB shown in FIG. 4A is a peak point of the AC power supply voltage Vac.

  FIG. 4B is a voltage waveform at the terminal RA5 of the microprocessor U1 of the controller 1a. FIG. 4B shows a half-wave rectified waveform of the AC power supply AC. The half-wave is used for simplifying a circuit for transmitting data (control signal). That is, data is transmitted only when the polarity of the AC power supply AC is one. This does not limit the synchronization method of the controller 1a. In FIG. 4B, Vth is a reference voltage of a comparator provided in the microprocessor U1 of the controller 1a. t0 is a zero cross point.

  FIG. 4C shows waveforms detected inside the microprocessor U1 of the controller 1a. In FIG.4 (c), Tp shows the period of a waveform. Tw is the pulse width. Pr indicates a rising edge, and Pf indicates a falling edge.

  FIG. 4D shows a voltage waveform at the terminal RA0 of the microprocessor U1 of the controller 1a. FIG. 4D shows an example of data (control signal) transmitted from the controller 1a to the LED lamp 2a. Hereinafter, a case where the pulse train “1100110101” is transmitted as a control signal will be specifically described. Of the pulse train to be transmitted, 2 bits “11” in the center SB is a preset reference pulse train. Of the pulse train to be transmitted, 4 bits “1100” before the central SB and 4 bits “0101” after the center SB are operation pulse trains (information bits) for operating the LED module of the LED lamp 2a. The LED module of the LED lamp 2a corresponds to the operation unit 5 shown in FIG.

  T1 shown in FIG. 4B is a data transmission start point. Ts is the time from the rising Pr to the data transmission start point t1. That is, Ts indicates the data transmission timing from the rising Pr. The microprocessor U1 of the controller 1a starts data transmission before the time tp at the peak point PB after the zero cross point t0 and the rising Pr. Note that the microprocessor U1 of the controller 1a assigns the reference pulse train to the first period including the peak point PB. t11 is a data transmission end point. The microprocessor U1 of the controller 1a finishes sending data after the falling Pf and the next zero cross point t0 after the time tp. The microprocessor U1 of the controller 1a assigns operation pulse trains to the second period after the rising Pr and before the first period and the third period after the first period and before the falling Pf.

  FIG. 4E shows a waveform of the voltage VL between the AC output terminals ZL_H and ZL_C of the controller 1a. Vd is the drain voltage of the field effect transistor Q1. When the pulse train “1100110101” is transmitted from the terminal RA0 of the microprocessor U1 of the controller 1a, the voltage VL decreases by an amount corresponding to the drain voltage Vd during the period when the bit value “0” is assigned. The reference pulse train does not include the bit value “0”. For this reason, the voltage supplied to the LED lamp 2a in the first period including the peak point PB does not decrease. The operation pulse train includes a bit value “0” as necessary. For this reason, the voltage supplied to the LED lamp 2a decreases before and after the first period including the peak point PB.

  As shown in FIG. 2, the AC output terminal ZL_H of the controller 1a is connected to one terminal (1) of the AC power supply AC. The AC output terminal ZL_C of the controller 1a is connected to the drain of the field effect transistor Q1. The source of the field effect transistor Q1 is connected to the other terminal (2) of the AC power supply AC. The gate of field effect transistor Q1 is connected to the collector of bipolar transistor Q2 via diode D2. The anode of diode D2 is connected to the collector of bipolar transistor Q2. The cathode of the diode D2 is connected to the gate of the field effect transistor Q1. The base of the bipolar transistor Q2 is connected to the terminal RA0 of the microprocessor U1 via the resistor R3. The emitter of the bipolar transistor Q2 is connected to the source of the field effect transistor Q1.

  A resistor R1 is connected between the gate and source of the field effect transistor Q1. A zener diode ZD1 and a diode D1 are connected in series between the gate and drain of the field effect transistor Q1. The anode of the diode D1 is connected to the drain of the field effect transistor Q1. The anode of the Zener diode ZD1 is connected to the gate of the field effect transistor Q1. The cathode of the Zener diode ZD1 is connected to the cathode of the diode D1.

When the bipolar transistor Q2 is turned on (ON state), the drain voltage Vd is expressed by the following equation.
Vd = Vt + Vz
Therefore, the voltage VL between the AC output terminals ZL_H and ZL_C is expressed by the following equation.
VL = Vac−Vd
Vt is the gate threshold voltage of the field effect transistor Q1. Vz is a Zener voltage of the Zener diode ZD1. The drain voltage Vd corresponds to a value obtained by adding the gate threshold voltage of the field effect transistor Q1 and the Zener voltage of the Zener diode ZD1. Voltage VL corresponds to a value obtained by subtracting drain voltage Vd from voltage Vac of AC power supply AC.

When the bipolar transistor Q2 is turned off (OFF state), the drain voltage Vd is expressed by the following equation.
Vd = Vds (ON) ≒ 0V
The diode D5, the resistor R7, the Zener diode ZD3, and the capacitor C2 are power supply circuits for generating the DC voltage VB. A diode D5, a resistor R7, and a resistor R2 are connected in series between one terminal (1) of the AC power supply AC and the collector of the bipolar transistor Q2. The anode of the diode D5 is connected to one terminal (1) of the AC power supply AC. The voltage VB corresponds to the voltage at the connection point of the resistors R7 and R2. The diode D2 is connected between the connection point of the resistor R2 and the collector of the bipolar transistor Q2 and the gate of the field effect transistor Q1.

When the forward voltage drop of the diode D2 is ignored and the bipolar transistor Q2 is turned off, the voltage Vg is expressed by the following equation.
Vg = VB * R1 / (R1 + R2)
VB, R1, and R2 are selected so that the voltage Vg is greater than the gate threshold voltage Vt, and Vds (ON) ≈0V. Therefore, if the bipolar transistor Q2 is in the OFF state, VL = Vac is established. If the bipolar transistor Q2 is in the ON state, VL = Vac−Vd is established.

  When the control signal is not transmitted, the controller 1a sets P_Tx = 0V and holds the bipolar transistor Q2 in the OFF state. When transmitting the control signal, the controller 1a outputs a pulse train P_Tx from the terminal RA0 and applies the pulse signal to the gate of the field effect transistor Q1. Thereby, the controller 1a adds the voltage VL between the AC output terminals ZL_H and ZL_C to the value obtained by adding the Zener voltage Vz of the Zener diode ZD1 and the gate threshold voltage Vt of the field effect transistor Q1 than when no pulse signal is applied. Decrease by the corresponding amount.

  When the controller 1a has the configuration shown in FIG. 2, a general-purpose product used for driving a motor of an electric vehicle or the like can be used as the field effect transistor Q1. For example, when VB = 15V, R1 = 200Ω, and R2 = 300Ω, Vg≈6V and Vds (ON) ≈0.6V (for example, conduction current 25A), and the above operation can be performed stably.

  The diodes D1 and D2 play a role of preventing a backflow when a pulse train is transmitted by turning on and off the bipolar transistor Q2. The reference pulse train is a signal for confirming the voltage value of the AC power supply AC. That is, the reference pulse train is a signal for the reception-side LED lamp 2a to know the peak value of the voltage of the AC power supply AC.

  With the controller 1a having the above configuration, even when a control signal is transmitted to the LED lamp 2a via the power line 4, the fluctuation of the output voltage can be made extremely small. For example, in the method of the present invention, the output impedance of the signal transmission circuit is equivalent to the AC power supply load, and the signal current is about several A to 20 A. For this reason, the signal power per bit of the signal pulse train can secure several tens of watts on the receiving side even if the signal voltage is 10V. Therefore, highly reliable communication can be expected even with a Zener voltage Vz = 5V. Note that when the zener voltage Vz = 5V, the decrease in the AC power supply voltage is about 10V. This decrease of 10V corresponds to a decrease of 7% of the peak voltage 141V if AC100V, and corresponds to a decrease of 3% if AC200V. Such a decrease is within the allowable range of commercially available electrical products.

  The withstand voltage between the source and drain of the field effect transistor Q1 may be a value that can withstand the amplitude of the voltage Vd = Vt + Vz (for example, 10-20V) when the control signal is transmitted. For this reason, it is not necessary to use the switching semiconductor which has a high withstand voltage unlike the past.

Generally, a switching semiconductor having a high withstand voltage has the following characteristics.
・ Low allowable current.
・ High ON resistance.
For example, in the system described in Patent Document 1, a semiconductor is normally short-circuited by a mechanical relay contact circuit to prevent heat generation of the switching semiconductor. The mechanical relay contact circuit is opened only when a signal is transmitted, and the AC power supply is intermittently connected with a switching semiconductor. Further, in the system described in Patent Document 1, since a large current cannot be switched, the current that can be supplied to the load device is about 10A.

  If it is the controller 1a which has the said structure, even if it uses the general purpose goods utilized for the motor drive of an electric vehicle etc. as the field effect transistor Q1, if the electric current of the load apparatus 2 whole is about 200 A, it will be satisfactory. Can be controlled.

FIG. 5 is a diagram showing an application example of the control system in the first embodiment of the present invention.
In the example shown in FIG. 5, the downlight ZD and the copy machine ZCP are connected in parallel to the controller 1a via the switch SW1. The LED lamp 2a, the shredder ZM, the personal computer ZPC, and the ventilation fan ZF are connected in parallel to the controller 1a via the switch SW2. The switch SW3, the switch SW4, and the switch SW5 are each connected in series to the switch SW2. The ventilation fan ZF is connected to the controller 1a via the switch SW3. The personal computer ZPC is connected to the controller 1a via the switch SW4. The shredder ZM is connected to the controller 1a via the switch SW5.

  The wiring system shown in FIG. 5 assumes a case where a controller 1a and an LED lamp 2a are added later to a facility where facilities such as a downlight ZD and a ventilation fan ZF are already installed. For example, if the allowable load of the existing equipment is 30A / 100V, even if 50 LED lamps 2a are added, if the total load is 30A / 100V or less, the controller 1a having the above configuration will cause each LED to The lamp 2a can be controlled without hindrance. Since the voltage fluctuation at the time of transmitting the control signal to the LED lamp 2a is slight, it is possible to prevent the generation of noise from the ventilation fan ZF and the flashing of the downlight ZD when transmitting the control signal.

  Therefore, when the controller 1a and the LED lamp 2a are added later to an existing facility, it is not necessary to change the on-site wiring inside the ceiling and the wall. In addition, when surveying on-site wiring including wiring on the back of the ceiling and inside the wall and making the wiring of the LED lamp system independent from these wirings, the construction cost alone often exceeds the price of the LED lamp. If it is this invention, a construction period can be shortened and it is possible to reduce the expense which construction requires.

  Next, the operation of the controller 1a when transmitting a control signal will be described with reference to FIG. FIG. 6 is a flowchart showing the operation of the controller 1a. Specifically, FIG. 6 shows the contents of a program incorporated in the microprocessor U1 of the controller 1a.

  The microprocessor U1 of the controller 1a includes a timer and a comparator. First, the microprocessor U1 initializes a timer and a comparator (S101). Next, the microprocessor U1 measures the period Tp and the pulse width Tw based on the input to the terminal RA5. The microprocessor U1 calculates the data transmission timing Ts based on the measured period Tp and pulse width Tw (S102).

  The microprocessor U1 waits for an interrupt at the rising edge Pr (see FIG. 4C) in S103. Operation panel OP. P is a device that is operated when the user wants to change the illuminance of the LED lamp 2a. When the microprocessor U1 detects the rising edge Pr of the pulse, the operation panel OP. Information from P is read (S104). The microprocessor U1 has an operation panel OP. When a control signal transmission request is received from P (Yes in S105), a pulse train P_Tx that matches the content of the request is transmitted from terminal RA0 (S106). For example, the microprocessor U1 transmits a pulse train “1100110101” from the terminal RA0. As a result, the voltage supplied to the LED lamp 2a changes as shown in FIG.

Next, the function of the LED lamp 2a will be specifically described.
FIG. 4F shows the voltage waveform at the point (f) in FIG. FIG. 4F corresponds to the voltage waveform at the terminal RA5 of the microprocessor U1 of the LED lamp 2a. A resistor R1 and a resistor R2 are connected in series between the + terminal and the − terminal of the rectifier BD1. The point (f) shown in FIG. 3 is a connection point between the resistors R1 and R2. That is, FIG. 4F shows a waveform of the voltage rectified by the rectifier BD1.

  The microprocessor U1 of the LED lamp 2a includes a timer, a comparator, and an AD converter. In FIG. 4F, Vth indicates a reference voltage of a comparator provided in the microprocessor U1. V1 is the peak value of the voltage. In the present embodiment, the microprocessor U1 of the controller 1a assigns the reference pulse train to the first period including the peak point PB. For this reason, the peak value of the voltage when the control signal is sent and the peak value of the voltage when the control signal is not sent (no signal) are both V1.

In FIG. 4F, RxVL (t) indicates the voltage waveform at the terminal RA5 of the microprocessor U1. Moreover, the voltage waveform at the time of no signal is represented by the following equation.
Sg = V1 · Sin (ωt)
ω is an angular frequency of the AC power supply AC. The microprocessor U1 calculates the voltage Sg when there is no signal from the voltage value V1 at the peak point PB.

FIG. 4G shows a waveform detected inside the microprocessor U1 of the LED lamp 2a. In FIG. 4G, Dt is the pulse width. The microprocessor U1 measures the pulse width Dt using an internal timer and a comparator. Pf indicates the falling edge of the comparator. A time τ from the falling Pf to the base point of the pulse train P_Tx is expressed by the following equation.
τ = Ts−Dt / 2
4F and 4G, Ts represents the time from the zero cross point to the base point of the pulse train P_Tx. The time Ts is preset in the controller 1a.

  Next, the operation of the LED lamp 2a when a control signal is received will be described with reference to FIG. FIG. 7 is a flowchart showing the operation of the LED lamp 2a. Specifically, FIG. 7 shows the contents of a program incorporated in the microprocessor U1 of the LED lamp 2a.

  The microprocessor U1 of the LED lamp 2a includes a timer, a comparator, an AD converter, and a pulse width modulator. First, the microprocessor U1 initializes an internal timer, a comparator, an AD converter, and a pulse width modulator (S201). Next, the microprocessor U1 measures the pulse width Dt based on the input to the terminal RA5. The microprocessor U1 calculates the data arrival timing, that is, the time τ based on the measured pulse width Dt (S202).

In step S203, the microprocessor U1 waits for an interrupt at the rising edge Pr. The microprocessor U1 starts AD conversion when detecting the rising edge Pr of the pulse. Specifically, the microprocessor U1 performs demodulation processing of the control signal by comparing the input voltage RxVL (t) to the terminal RA5 with the calculated voltage Sg (S204). A calculation formula (following formula) for performing the comparison is incorporated in the microprocessor U1 in advance.
Sga = {V1 · Sin (ωt) −RxVL (t)}

  The difference Sga is an analog value. For this reason, the microprocessor U1 uses the threshold value to digitize, and returns to negative logic to reproduce the pulse train. As the threshold value, for example, a value corresponding to Vd / 2 (Vd * V1 / PB / 2) is used. For example, if bit values “0” and “1” are mixed in the demodulated pulse train Sgd, the microprocessor U1 detects that the pulse train Sgd is a control signal (Yes in S205). When the demodulated pulse train Sgd is a control signal, the microprocessor U1 generates a pulse width modulation signal Dmg PWM based on the demodulated pulse train “1100110101”. The pulse width modulation signal Dmg PWM is a signal for changing the illuminance of the LED module, for example. The microprocessor U1 outputs the generated pulse width modulation signal Dmg PWM to the LED module, and performs PWM control (S206).

  In the LED lamp 2a having the above configuration, the voltage Sg at the time of no signal is calculated from the voltage value V1 at a predetermined position, and the pulse train is reproduced from the difference between the calculation result, the reception voltage RxVL (t), and the threshold value. For this reason, for example, it is possible to detect the fluctuation of the AC power supply voltage generated at the time of operation or stop of the manufacturing facility in a factory or the like, and perform demodulation after correcting the voltage fluctuation. Further, if the reliability of demodulation is improved by employing an error correction code and other techniques in the reproduction program of the received signal, the signal speed can be increased. Further, if the reliability of demodulation is improved, the modulation amplitude (Vd) on the transmission side can be reduced to further reduce the influence on other electrical devices. In particular, when this control system operates on the same wiring as a device that requires high reliability such as a medical device, it is important that the modulation amplitude (Vd) can be reduced.

  If it is the control system in Embodiment 1 of this invention, a control signal can be transmitted to the load apparatus 2 via the power line 4 without interfering with the normal operation of the load apparatus 2. As is clear from the above description, for example, if the reliability of communication can be ensured even if the modulation amplitude is reduced by improving the technique, the modulation amplitude Vd = Vt can be set. If such a technique can be established, the Zener diode ZD1 becomes unnecessary.

The present control system can also be expected to have the following effects.
-By improving the performance of the noise suppression program for the power line 4, the S / N of communication can be improved and the voltage amplitude during signal transmission can be reduced. Thereby, communication can be performed with almost no loss of transmitted power, and malfunction of the load device 2 can be prevented. When the LED lamp 2a is used as the load device 2, the brightness flicker of the LED module can be prevented.
-Higher transmission speed can be expected. For example, a speed increase of 50K baud or more can be expected. Although description is omitted in the present embodiment, information transmission by analog signals may be performed by applying an analog signal to the gate of the field effect transistor Q1 of the controller 1a. The SB can be used as a reference value for an analog signal. If analog signal transmission is further developed, image transmission is possible.

As the field effect transistor Q1 of the controller 1a, for example, when an on-vehicle FET having an on-resistance of 2 mΩ or less is used, it is not necessary to protect the switching element with a mechanical relay as in the prior art. The configuration of the controller 1a can be simplified. Moreover, load control of a large current (for example, 50 A at 100 V / 200 V) is possible at low cost.
-Unlike the conventional PLC modem system (high frequency carrier system) using a carrier wave of several tens of MHz, there is no possibility of generating jamming radio waves from the power line.

DESCRIPTION OF SYMBOLS 1 Controller 2 Load apparatus 3 AC power supply 4 Power line 5 Operation | movement part 6 Transmission part 7 Demodulation part 8 Control part 1a Controller U1 Microprocessor, R1-R7 resistance, C1-C2 capacitor | condenser, D1-D5 diode, ZD1-ZD3 Zener diode Q1 field effect transistor, Q2 bipolar transistor, OP. P Operation panel, ZL_H, ZL_C AC output terminal 2a LED lamp U1 Microprocessor, R1-R2 resistor, C1-C2 capacitor, BD1 rectifier, ZL_H, ZL_C AC input terminal

Claims (6)

A load device having an operating part;
A controller for supplying AC power to the load device via a power line and operating the operating unit;
With
The controller is
By the said load device for supplying a voltage Do things Ku low to zero except zero-crossing point of the AC waveform, and transmitting means for transmitting a control signal to the load device via the electric power line,
With
The load device is:
Demodulation means for demodulating the control signal received from the controller;
Control means for controlling the operating unit based on a result demodulated by the demodulation means;
Equipped with a,
The controller further includes a first AC output terminal and a second AC output terminal connected to the power line,
The first AC output terminal is connected to a first terminal of an AC power source;
The transmission means includes
A field effect transistor having a drain connected to the second AC output terminal and a source connected to the second terminal of the AC power supply;
A diode connected between the gate and drain of the field effect transistor;
Control system equipped with. The transmission means further comprises a Zener diode ,
The control system according to claim 1, wherein the diode and the Zener diode are connected in series between a gate and a drain of the field effect transistor .   The transmitting means applies a pulse signal to the gate of the field effect transistor, thereby causing the voltage between the first AC output terminal and the second AC output terminal to be higher than when no pulse signal is applied. The control system according to claim 2, wherein the control signal is transmitted by reducing the voltage by an amount corresponding to the sum of the voltage and the gate threshold voltage of the field effect transistor.   The transmission means allocates a predetermined reference pulse train in a first period including a peak point of an AC waveform of a voltage supplied to the load device when transmitting a control signal to the load device, and at the peak point, the load device is assigned to the load device. The control system according to claim 3, wherein the supplied voltage is not reduced.   The transmission means assigns an operation pulse train for operating the operation unit to a second period before the first period and a third period after the first period, and the load device before and after the peak point The control system according to claim 4, wherein the voltage supplied to the power supply is reduced in a pulse shape.   The demodulating means demodulates the control signal transmitted by the transmitting means by comparing the voltage rectified by a full-wave rectifying element and the no-signal voltage calculated from the voltage value at the peak point. The control system according to claim 5.

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