JP2001128267A - Terminal for remote monitor control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an abnormal rise in an output voltage of a power supply circuit. SOLUTION: A switching regulator having a function of output stop and employing this function for an abnormal voltage detection signal, is adopted for a voltage step-down circuit DC in a power supply circuit 12 that converts an AC power supply supplied from an external power supply into a DC voltage. The terminal is provided with an abnormal voltage detection circuit 10 that monitors a level of a DC voltage output of the power supply circuit 12 and outputs an abnormal voltage detection signal to the switching regulator when this level is deviated from a prescribed range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a remote monitoring and control system that transmits a transmission signal to a signal line by a time division multiplex transmission system and enables load control by operating a switch using the transmission signal. The present invention relates to a terminal of a remote monitoring and control system capable of controlling a load by operating a switch provided on another terminal.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a configuration proposed by the present applicant as a remote monitoring control system of this kind (Japanese Patent Application No. 11-83469). In this remote monitoring control system, a two-wire signal line Ls is connected to a transmission control device (transmission unit) 30, and an individual switch 31a and a dimming switch 31b are connected to the signal line Ls as an operation terminal. On the other hand, the relay terminal (relay control T
/ U) 32 and dimming terminal (inverter fluorescent lamp dimming T)
/ U) 33p is connected as a control terminal. Here, the individual switch 31a, the dimming switch 31b, the relay terminal device 32, and the dimming terminal device 33p are multidrop-connected to the signal line Ls.

[0003] Individual switch 31a, dimmer switch 31
b, the relay terminal 32 and the dimming terminal 33p are set with individual addresses, respectively.
Uses these addresses to identify the individual switches 31a,
The dimming switch 31b, the relay terminal 32, and the dimming terminal 33p are individually recognized. The individual switch 31a includes a maximum of four switches Sa, and the dimming switch 31b includes an up switch Su, a down switch Sd, and an on / off switch Sb. The relay terminal 32 is connected to a relay (remote control relay) Ry for controlling a load. In general, a latching type relay is used as the relay Ry, and the relay terminal 32 operates the relay Ry when
Power is supplied from a transformer (relay transformer) T1 to the relay Ry in a pulsed manner. The dimming terminal device 33p is for a fluorescent lamp, and provides a dimming signal for instructing a light output to a lighting fixture L for lighting a fluorescent lamp, which is a lighting load, at a high frequency by an inverter functioning as a dimmer. Be composed. The output of the transformer T2 is connected to the dimming terminal 33p.

Next, the operation of the remote monitoring control system will be briefly described. However, for the sake of simplicity, the individual switch 31a and the dimming switch 31b will be collectively called an operation terminal, and the relay terminal 32 and the dimming terminal 33p will be collectively called a control terminal as appropriate.

The transmission control device 30 sends out a transmission signal Vs having a format shown in FIG. 7A to the signal line Ls. That is, the synchronization signal SY indicating the start of signal transmission,
Mode data MD indicating the mode of the transmission signal Vs, address data AD for individually calling the operation terminal and the control terminal, control data CD for giving instructions to the control terminal and the operation terminal, and detection of a transmission error. It is a bipolar (± 24 V) time-division multiplexed signal composed of a checksum data CS, a signal return period WT which is a time slot for receiving a return signal (monitoring data) from an operation terminal or a control terminal, and pulse width modulation. Thus, data is transmitted (FIG. 6B). When the address data AD transmitted by the transmission signal Vs received via the signal line Ls matches the preset address, each operation terminal and each control terminal fetches the control data CD from the transmission signal Vs. When there is monitoring data to be transmitted, the monitoring data is returned as a current mode signal (a signal transmitted by short-circuiting the signal line Ls via an appropriate low impedance) during the signal return period WT of the transmission signal Vs.

When data is transmitted from the transmission control device 30 to a desired operation terminal or control terminal, the mode data MD is set to a control mode, and the address of the operation terminal or control terminal is set to address data AD. When the signal Vs is transmitted and the transmission signal Vs is transmitted to the signal line Ls, the operation terminal or the control terminal corresponding to the address data AD receives the control data CD and returns the monitoring data during the signal return period WT. The transmission control device 30 confirms that the control data CD has been transmitted to the desired operation terminal or control terminal based on the relationship between the transmitted control data CD and the monitoring data received during the signal return period WT. The control terminal instructs the operation of the relay Ry or the change of the dimming signal in accordance with the received control data CD, and the operation terminal outputs a monitoring signal for confirming the operation in accordance with the received control data CD.

On the other hand, the transmission control device 30 normally transmits the transmission signal Vs in which the mode data MD is set to the dummy mode at regular time intervals (constant polling). Is transmitted, an interrupt signal as shown in FIG. 7C is generated in synchronization with the synchronization signal SY of the transmission signal Vs in the dummy mode. At this time, the operation terminal sets the interrupt flag to prepare for the subsequent information exchange with the transmission control device 30. Upon receiving the interrupt signal, the transmission control device 30 sets the mode data MD to the interrupt polling mode and sequentially increases the upper half of the address data AD (the upper 4 bits if the address data AD is 8 bits). In the operation terminal that has transmitted the transmission signal and generated the interrupt signal, when the upper 4 bits of the address data AD in the transmission signal in the interrupt polling mode match the upper 4 bits of the address set in the operation terminal. And the signal return period W
The lower half bits of the address are transmitted to T
Return to. As described above, since the transmission control device 30 collectively searches for 16 operation terminals that have generated the interrupt signal,
The operation terminal can be found in a relatively short time.

When the transmission control device 30 obtains the address of the operating terminal that has generated the interrupt signal, the mode data MD is set to the monitoring mode, and a transmission signal having the obtained address data AD is transmitted to the signal line Ls. In response to the signal, the operation terminal returns information to be transmitted in the signal return period WT. Finally, the transmission control device 30 sends a signal for instructing an interrupt reset to the operation terminal that has generated the interrupt signal, and releases the interrupt flag of the operation terminal.

As described above, information transmission from the operation terminal device to the transmission control device 30 is performed four times from the transmission control device 30 to the operation terminal device (dummy mode, interrupt polling mode, monitoring mode, (Interrupt reset). When the transmission control device 30 wants to know the desired operating state of the control terminal, it is only necessary to transmit a transmission signal using the mode data MD as monitoring data.

In short, the switch Sa, the up switch Su, the down switch Sd, and the on / off switch Sb
Is operated to generate operation data, the operation terminal returns monitoring data corresponding to the operation data to the transmission control device 30. When the transmission control device 30 transmits the control data CD to the control terminal, the control The terminal device controls the relay Ry and adjusts the light output of the lighting device L. In this way, by transmitting and receiving data between the terminals using the correspondence of the addresses set in the transmission control device, the load is controlled by another terminal in accordance with the operation of the switch provided in one of the terminals. I do.

By the way, the up switch Su provided in the dimming switch 31b instructs to increase the light output by a pressing operation, the down switch Sd instructs to decrease the light output by a pressing operation, and the switch Sb is turned on and off by the pressing operation. Instruct. The up switch Su and the down switch Sd generate the above-mentioned interrupt signal at the start of the push operation and at the end of the push operation, and instruct the increase or decrease of the light output during the push operation.

The dimming terminal 33p is, as shown in FIG.
The lighting device L includes a dimming signal output circuit 11 that outputs a dimming signal to an inverter circuit as a dimmer built in the lighting fixture L, and supplies a DC power (10.5 V) to the dimming signal output circuit 11 and the short-circuit detection circuit 14. And a power supply circuit 12p. The dimming signal is a pulse signal for instructing a dimming amount by a duty ratio. The power supply circuit 12p includes a transformer T
2 supplies power. The transformer T2 applies an AC voltage of 100 V to 200 V, which is a commercial power supply, to a signal line Ls
Is reduced to the same 24 V AC voltage as the transmission signal transmitted. The power supply circuit 12p includes a transformer T
Rectifier circuit RE consisting of diode bridge
And the voltage is reduced to 10.5 V by a step-down circuit DC using a switching regulator. Conventionally, the power supply circuit 12p shown in FIG. 8 may be configured by the circuit shown in FIG. In the example of FIG. 9, the power supply circuit is a transformer T
Step-down transformer T3 for stepping down the output voltage of No. 2 to 12 V, rectifier circuit RE for rectifying the output, and rectifier circuit RE
Series regulator (3
(Integrated as a terminal regulator).

A dimming switch 31 is provided in the dimming terminal 33p.
A dimming signal generation circuit 13 is also provided to output a dimming signal in response to the pressing operation of b. Dimming signal generation circuit 1
In 3, the output is changed so as to increase or decrease the light output of the lighting device L by the start of the push operation of the up switch Su and the down switch Sd, and the change of the output is stopped by the end of the push operation of the up switch Su and the down switch Sd. . The dimming signal is generated in the dimming signal output circuit 11 in response to the output of the dimming signal generation circuit 13.
The dimming signal output circuit 11 generates a dimming signal suitable for the dimmer provided in the lighting fixture L based on the output of the dimming signal generation circuit 13. Therefore, the up switch Su
The light output of the lighting fixture L increases during a period in which the button is pressed, and decreases while the down switch Sd is pressed. Since the dimming range of the luminaire L is predetermined, the light output stops when the maximum or minimum value of the dimming range is reached by operating the up switch Su and the down switch Sd. The switch Sb instructs on / off of the lighting equipment L. The address of the switch Sb is associated with the relay terminal 32, and the power to the lighting equipment L is controlled by the relay Ry controlled by the relay terminal 32. It is turned on and off. In short, each lighting fixture L is controlled using the relay terminal 32 and the dimming terminal 33p.

Japanese Patent Application Laid-Open No. 6-335068 discloses a remote monitoring control system employing a circuit corresponding to FIG.

[0015]

However, in the configuration shown in FIG. 8, the voltage dividing circuit for feeding back the voltage for setting the output voltage of the power supply circuit 12p to the switching regulator of the step-down circuit DC has an output of the step-down circuit DC. It is generally provided in a stage. In this case, if the resistance of the voltage dividing circuit is opened or short-circuited for some reason, the output voltage of the power supply circuit 12p abnormally rises.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a terminal of a remote monitoring and control system capable of suppressing an abnormal increase in output voltage of a power supply circuit.

[0017]

According to a first aspect of the present invention, there is provided a transmission control apparatus comprising: a plurality of terminals each having an address connected to a signal line; A transmission signal is transmitted and received between the terminals by the time-division multiplex transmission method, and data is transmitted and received between the terminals by using an address correspondence set in the transmission control device. A terminal device used in a remote monitoring and control system for controlling a load by another terminal device according to operation of a provided switch, the switching device having a function of stopping output and using this function according to an abnormal voltage detection signal. A power supply circuit including a regulator for converting an AC power supplied from an external power supply into a DC voltage, and monitoring a level of the DC voltage, and the level is out of a predetermined range. , Than it and an abnormal voltage detection circuit for outputting the abnormal voltage detection signal to the switching regulator.

With this configuration, when the level of the DC voltage from the power supply circuit is out of the predetermined range, an abnormal voltage detection signal is output from the abnormal voltage detection circuit to the switching regulator, and the output of the switching regulator stops.
An abnormal increase in the output voltage of the power supply circuit is suppressed.

In the terminal of the remote monitoring control system according to the first aspect, the abnormal voltage detection circuit includes a series circuit of a Zener diode to which the DC voltage is applied and a resistor, and determines a breakdown characteristic of the Zener diode. The voltage generated at both ends of the resistor may be used as the abnormal voltage detection signal and output to the switching regulator. With this configuration, when the output level of the DC voltage of the switching regulator rises, the current flowing through the resistor at the moment when the Zener voltage is exceeded increases, and the voltage across the resistor rises. become. Therefore, if a malfunction occurs and the voltage across the resistor rises and an abnormal voltage detection signal is generated, the output of the switching regulator stops, the abnormal voltage detection signal disappears due to the drop in the voltage across the resistor, and the output of the switching regulator stops. A series of operations such as release (that is, re-driving of the switching regulator), generation of an abnormal voltage detection signal due to an increase in the voltage between both ends of the resistor, and stop of the output of the switching regulator are sequentially and repeatedly performed. The output level is suppressed to a certain level and becomes stable.

Further, in the terminal of the remote monitoring and control system according to claim 1 or 2, the light output of an illumination load, which is loaded with a dimming signal corresponding to a dimming amount instructed by using the transmission signal, is adjusted. And a dimming signal output circuit provided to the dimming device, wherein the DC voltage output is used as a power source of the dimming signal output circuit. According to this configuration, an abnormal increase in the output voltage of the power supply circuit can be suppressed.

[0021]

FIG. 1 is a block diagram showing the internal configuration of a terminal of a remote monitoring and control system according to an embodiment of the present invention, FIG. 2 is a specific circuit diagram of the terminal shown in FIG. 1, and FIG. FIG. 2 is a configuration diagram illustrating an example of a remote monitoring control system using the terminal device illustrated in FIG. 1, and the present embodiment will be described below with reference to these drawings.

The remote monitoring and control system shown in FIG. 3 has the same configuration as the remote monitoring and control system shown in FIG. 6 except that a dimming terminal 33 different from the dimming terminal 33p is incorporated. However, a transformer having a large rated output power (rated output current) is adopted as the transformer T2, and the number of the transformers T2 is reduced to one.

The dimming terminal 33 is a lighting fixture whose load to be controlled includes an inverter as a dimmer and uses a fluorescent lamp as a light source. The dimming terminal 33 supplies a dimming signal to the dimmer to control the lighting fixture. It controls the light output.

Specifically, as shown in FIG. 2, the dimming terminal 33 has two terminals N1 and N connected to a signal line Ls.
A diode bridge DB1 for non-polarization is provided between the two, a transmission signal is full-wave rectified by the diode bridge DB1, and a constant voltage circuit 21 converts the signal into a constant voltage. The part is getting power. The transmission signal is a diode bridge DB1.
Is subjected to half-wave rectification using a part of the signal and input to the signal processing unit 20 through the receiving circuit 22. The signal processing unit 20 has a microcomputer as a main configuration, and uses address data stored in a data storage unit 23 using an EEPROM as an address. The data stored in the data storage unit 23 includes not only address data but also parameters that determine the operation of the signal processing unit 20. That is, the signal processing unit 20 has a program related to a plurality of types of functions (for example, a terminal that controls a relay or a dimming terminal), and determines which program is used for data storage. The selection is made using the parameters stored in the section 23.

In the signal processing section 20, when the address data included in the transmission signal received through the receiving circuit 22 matches the address data stored in the data storage section 23,
It receives control data of a transmission signal and performs an operation according to the control data. Further, the reception of the transmission signal is transmitted from the terminals N1 and N2 to the signal line Ls through the return circuit 24. The return circuit 24 outputs a current mode binary signal to the signal line Ls according to two states: a state in which a resistor is connected between the output terminals of the diode bridge DB1 and a state in which the output terminals are opened.
To send to.

By the way, data can be written in the data storage section 23 by an infrared light wireless signal from a separately provided setting device. For this reason,
A wireless receiver 25 for receiving an optical wireless signal;
A wireless transmitter 26 for transmitting an optical wireless signal;
There is provided a reception notifying unit 27 for turning on and notifying a display lamp La1 composed of a visible light emitting diode which is turned on when receiving an optical wireless signal. Therefore, the setting device can transmit and receive an optical wireless signal to and from the dimming terminal, and not only writes data in the data storage unit 23 but also checks and corrects data stored in the data storage unit 23. It is made possible by the setting device. Further, since the signal processing unit 20 has a microcomputer as a main configuration, a crystal resonator XL is also connected to generate an internal clock signal.

As described with reference to FIG. 6 and the like, the dimming terminal 33 has a function of generating a dimming signal based on control data included in a transmission signal transmitted in accordance with the operation of the dimming switch. Have. A dimming signal generation circuit 13 for changing a dimming signal by operating a dimming switch (FIG. 1)
Is included in the signal processing unit 20, and the signal processing unit 20 outputs a binary signal having a duty ratio corresponding to the light control amount. This signal is sent to the dimming signal output circuit 11 via the transistor Q1 and the photocoupler PC constituting the rest of the dimming signal generation circuit 13. Signal processing unit 20
Operates using the power supply generated by the constant voltage circuit 21 from the transmission signal as described above, but the dimming signal output circuit 11 is supplied with power by a power supply circuit 12 provided separately. Therefore, the photocoupler PC is used to insulate between circuits having different power supplies.

The transistor on the output side of the photocoupler PC is connected in series to another transistor Q2. The dimming signal output circuit 11 includes a transistor Q3 that is turned on when both the photocoupler PC and the transistor Q2 conduct, and the transistor Q3 and two resistors R
2 and R3 are connected between both output terminals of the power supply circuit 12. Therefore, the voltage between both ends of the resistor R3 changes according to the on / off of the transistor Q3, and is supplied to the lighting equipment as a dimming signal. By the way, the transistor Q2 and the resistor R2 are used in a short circuit detecting circuit 14 for detecting the presence or absence of a short circuit between both ends of the resistor R3.

The short-circuit detecting circuit 14 has two comparators CP1 and CP2. The voltage across the resistor R2 is averaged by the diode D1, the resistor R4, and the capacitor C1, and the average voltage is compared with a reference voltage in the comparator CP1 as a voltage across the capacitor C1. The comparator CP2 compares the output of the comparator CP1 with the reference voltage, and is connected so that when the output of the comparator CP1 goes low, the output of the comparator CP2 also goes low. The output terminal of the comparator CP2 has an indicator light L composed of a visible light emitting diode.
One end of a2 is connected, and the base of the transistor Q2 is connected via the diode D2. When the output of the comparator CP2 becomes L level, the indicator lamp La
2 is turned on, and the transistor Q2 is turned off.

With the above configuration, when the both ends of the resistor R3 are short-circuited, the transistor Q3
Is turned on, the voltage across the resistor R2 becomes higher than normal, the voltage across the capacitor C1 rises,
It becomes higher than the reference voltage set in the comparator CP1. At this time, the output of the comparator CP1 becomes L level, and the output of the comparator CP2 also becomes L level.
When the transistor Q2 is turned off, the indicator light La2
Lights up. When the transistor Q2 is turned off, the transistor Q3 is also turned off, so that a short circuit between both output terminals of the power supply circuit 12 can be prevented.

The power supply circuit 12 for supplying power to the dimming output circuit 11 uses a step-down circuit DC composed of a switching regulator. The step-down circuit DC is a regulator composed of an integrated circuit including a switching element and a control circuit for the switching element. Circuit 12a and inductor L1
, A smoothing capacitor C2, a diode D3, and a resistor R
5, R6. The resistors R5 and R6 are connected between the output terminals of the step-down circuit DC, divide the output voltage of the step-down circuit DC, and feed back to the regulator circuit 12a to stabilize the output voltage of the power supply circuit 12. This kind of step-down circuit DC is known as a step-down chopper circuit. The power supply circuit 12 includes a rectifier RE for rectifying the secondary output of the transformer T2 and a rectifier R
A smoothing capacitor C0 for smoothing the output of E is provided. The voltage across the smoothing capacitor C0 is input to the step-down circuit DC.
Step down to 0.5V.

Here, to summarize the configuration of the dimming terminal 33, as shown in FIG. 1, a commercial power supply is stepped down to 24 volts AC by a transformer T2 provided separately from the dimming terminal 33. The power is input to the circuit 12. In the power supply circuit 12, the AC 24V is rectified and smoothed by a rectifier circuit RE (including a smoothing capacitor C0) to a DC 24V, and the voltage is lowered by a step-down circuit DC and made constant to obtain a DC 10.5V. The output voltage of the step-down circuit DC is supplied to the dimming signal output circuit 11 and the short-circuit detection circuit 14, and the dimming signal output circuit 11 outputs a dimming signal according to an instruction from the dimming signal generation circuit 13. The dimming signal generation circuit 13 is specifically realized by the signal processing unit 20 of the dimming terminal 33 as described above, and includes the dimming signal generation circuit 13 and the dimming signal output circuit 1.
1 is insulated by a photocoupler PC.

The dimming terminal 33 configured as described above is provided with the abnormal voltage detecting circuit 10 at the output stage of the power supply circuit 12 as a feature of the present embodiment. The abnormal voltage detection circuit 10 monitors the level of the DC voltage output of the power supply circuit 12, and outputs an abnormal voltage detection signal, in which the voltage becomes equal to or higher than a predetermined level, to the regulator circuit 12a when the level is out of a predetermined range. It is. The regulator circuit 12a employs a switching regulator having a function of stopping (cutting) output, and the switching regulator is configured to use the function of stopping output in response to the abnormal voltage detection signal.

For example, when an IC of LM2575T-ADJ manufactured by National Semiconductor is adopted as the regulator circuit 12a, the abnormal voltage detection circuit 10 is connected to the negative output terminal of the power supply circuit 12 and the regulator circuit 12a as shown in FIG. Resistor R1 connected between the fifth terminal
0 and a Zener diode D10 having a cathode and an anode connected to the positive output terminal of the power supply circuit 12 and the fifth terminal of the regulator circuit 12a, respectively (this configuration is referred to as “configuration A”). In the case of the “Configuration A”, the level of the DC voltage output of the power supply circuit 12 increases, and the moment the level exceeds the Zener voltage, the current flowing through the resistor R10 increases, and the voltage across the resistor R10 increases. On the other hand, in the case of the configuration of FIG. 8, the fifth terminal of the regulator circuit 12a is connected to the negative output terminal of the rectifier circuit RE (this configuration is referred to as “configuration B”).

The output of the LM2575T-ADJ is 0 V (off) by the output stop function when the applied voltage at the fifth terminal is higher than 2.4 V, that is, when it is at the H level. Is lower than 0.8 V, that is, if it is at the L level, the value is normally set (ON). For example, the MA1130 is connected to the Zener diode D10.
If -L is adopted and the resistance value of the resistor R10 is set to 220Ω, when the resistors R5 and R6 are opened or short-circuited for some reason, in the case of the “configuration B”, as shown in FIG. While the output level of the power supply circuit 12p abnormally rises to about 0.5V, in the case of the "configuration A",
As shown in FIG. 5, it can be seen that the rise in the output level of the power supply circuit 12 is suppressed to about MAX 14.5V. In the case of this configuration example, the voltage across the resistor R10 that is higher than 2.4 V as the H level is the abnormal voltage detection signal described above. 4A and 4B show how the DC voltage output level of the power supply circuit 12p changes when R6 is short-circuited and R5 is opened, respectively. FIGS. 5A and 5B show R6 short-circuited and R5 opened, respectively. The state where the DC voltage output level of the power supply circuit 12 changes at times is shown.

As described above, the abnormal rise of the output voltage of the power supply circuit can be suppressed by providing the abnormal voltage detection circuit 10 and employing the switching regulator having the function of stopping the output. In other words, if a malfunction occurs and the voltage across the resistor R10 rises to the H level or more and an abnormal voltage detection signal is generated, the output of the regulator circuit 12a stops, and the abnormal voltage detection signal due to a drop in the voltage across the resistor R10 is generated. Disappearance, release of output stop of regulator circuit 12a (that is, re-drive of regulator circuit 12a), resistance R10
A series of operations such as generation of an abnormal voltage detection signal due to an increase in the voltage between both ends and stop of the output of the regulator circuit 12a are sequentially and repeatedly performed, and the output level of the DC voltage of the power supply circuit 12 is suppressed to a certain level. Will be stable.

In this embodiment, as an example, LM
Although the IC of 2575T-ADJ is employed in the regulator circuit 12a, the present invention is not limited to this. For example, another switching regulator having an output stop function may be used.

Similarly, as an example, MA1130-L is used for Zener diode D10 and the resistance value of resistor R10 is set to 220Ω, but it goes without saying that other elements and resistance values may be arbitrarily used. No. For example,
MA8130-H may be used for the Zener diode D10, and the resistance of the resistor R10 may be set to 240Ω.

Further, in the present embodiment, the dimming terminal which continuously changes the light output of the lighting equipment during the pressing operation of the switch provided in the dimming switch has been described. The technical idea of the present invention can also be applied to a dimming terminal device that generates a dimming signal so that the light output of the lighting fixture is changed stepwise every time a pressing operation is performed.

[0040]

As is apparent from the above description, according to the first aspect of the present invention, a plurality of terminals each having an address are connected to a signal line, and a transmission control device connected to the signal line is provided. A transmission signal is transmitted and received between the terminals by the time-division multiplex transmission method, and data is transmitted and received between the terminals by using an address correspondence set in the transmission control device. A terminal device used in a remote monitoring and control system for controlling a load by another terminal device according to operation of a provided switch, the switching device having a function of stopping output and using this function according to an abnormal voltage detection signal. Including a regulator, a power supply circuit that converts an AC power supplied from an external power supply into a DC voltage, and monitors a level of the DC voltage, and when this level is out of a predetermined range. Because and an abnormal voltage detection circuit for outputting the abnormal voltage detection signal to the switching regulator, it is possible to suppress the abnormal rise of the output voltage of the power supply circuit.

According to a second aspect of the present invention, in the terminal of the remote monitoring and control system according to the first aspect, the abnormal voltage detection circuit includes a series circuit of a Zener diode to which the DC voltage is applied and a resistor. By using the breakdown characteristic of the Zener diode, a voltage generated across the resistor is output to the switching regulator as the abnormal voltage detection signal, so that the output level of the DC voltage of the power supply circuit is suppressed to a certain level. Can be stabilized.

According to the third aspect of the present invention, in the terminal of the remote monitoring and control system according to the first or second aspect,
A dimming signal output circuit for applying a dimming signal corresponding to the dimming amount instructed using the transmission signal to a dimmer that adjusts a light output of an illumination load serving as a load; Since it is used as a power source of the optical signal output circuit, it is possible to obtain a dimming terminal capable of suppressing an abnormal increase in the output voltage of the power source circuit.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an internal configuration of a terminal of a remote monitoring and control system according to an embodiment of the present invention.

FIG. 2 is a specific circuit diagram of the terminal device shown in FIG.

FIG. 3 is a configuration diagram showing an example of a remote monitoring control system using the terminal device shown in FIG.

FIG. 4 is a diagram showing how the output voltage level of the power supply circuit of FIG. 8 changes at the time of a failure.

FIG. 5 is a diagram showing how the output voltage level of the power supply circuit of FIG. 1 changes at the time of a failure.

FIG. 6 is a diagram showing an example of a configuration separately proposed by the present applicant as a remote monitoring control system.

FIG. 7 is an explanatory diagram of the operation of the remote monitoring control system.

8 is a block diagram showing an internal configuration of the dimming terminal shown in FIG.

FIG. 9 is another conventional circuit configuration diagram employed in the power supply circuit shown in FIG.

[Explanation of symbols]

 Reference Signs List 10 abnormal voltage detection circuit 11 dimming signal output circuit 12 power supply circuit 14 short circuit detection circuit 30 transmission control device 31a individual switch 31b dimming switch 32 relay terminal device 33 dimming terminal device DC step-down circuit L lighting equipment Ls signal line Sa switch Sb On-off switch Sd Down switch Su Up switch T2 Transformer

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[Procedure amendment]

[Submission date] December 6, 1999 (1999.12.
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction contents]

The output of the LM2575T-ADJ is 0 V (off) by the output stop function when the applied voltage at the fifth terminal is higher than 2.4 V, that is, when it is at the H level. Is lower than 0.8 V, that is, if it is at the L level, the value is normally set (ON). For example, a Zener diode having a Zener voltage of 12.7 V
If the resistors R5 and R6 are opened or short-circuited for some reason if the resistance value of the resistor R10 is set to 220Ω by adopting the mode D10 , as shown in FIG. While the output level of the power supply circuit 12p abnormally rises to about MAX33.5V, in the case of the "configuration A", the rise in the output level of the power supply circuit 12 is suppressed to about MAX14.5V as shown in FIG. You can see that it is done.
In the case of this configuration example, the voltage across the resistor R10 that is higher than 2.4 V as the H level is the abnormal voltage detection signal described above. 4A and 4B show how the DC voltage output level of the power supply circuit 12p changes when R6 is short-circuited and R5 is opened, respectively. FIGS. 5A and 5B show R6 short-circuited and R5 opened, respectively. The state where the DC voltage output level of the power supply circuit 12 changes at times is shown.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction contents]

Similarly, as an example, the Zener voltage 12.
A 7V Zener diode D10 is adopted, and a resistor R1
Although the resistance value of 0 is set to 220Ω, it goes without saying that other elements and resistance values may be arbitrarily used .

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 4]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

[Procedure amendment 5]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

[Procedure amendment 6]

[Document name to be amended] Drawing

[Correction target item name] Fig. 6

[Correction method] Change

[Correction contents]

FIG. 6

[Procedure amendment 7]

[Document name to be amended] Drawing

[Correction target item name] Fig. 8

[Correction method] Change

[Correction contents]

FIG. 8

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K073 AA21 AA42 AA58 AB04 BA00 BA01 BA25 CA01 CB04 CE07 CE09 CE12 CF13 CF14 CF18 CF20 CG02 CG06 CG10 CG42 CH00 CH21 CJ00 CJ01 CJ02 CJ11 CJ17 CJ19 5K048 AA04 EB01 CB01 HA11 HA31

Claims (3)

[Claims] 1. A plurality of terminals each having an address are connected to a signal line, and a transmission signal is transmitted and received between the transmission control device connected to the signal line and each of the terminals by a time division multiplex transmission method. In addition, remote monitoring that controls the load by another terminal in response to the operation of a switch provided in one of the terminals by exchanging data between the terminals using the address correspondence set in the transmission control device A terminal device used in a control system, including a switching regulator having an output stop function and using this function in response to an abnormal voltage detection signal, and converting an AC power supplied from an external power supply into a DC voltage. A power supply circuit, monitors the level of the DC voltage, and when the level is out of a predetermined range, outputs the abnormal voltage detection signal to the switching regulator. Terminal unit of the remote monitoring control system and a that abnormal voltage detection circuit. 2. The abnormal voltage detecting circuit includes a series circuit of a Zener diode to which the DC voltage is applied and a resistor, and utilizes a breakdown characteristic of the Zener diode to detect a voltage generated at both ends of the resistor. 2. The terminal of the remote monitoring and control system according to claim 1, wherein the terminal is output to the switching regulator as a voltage detection signal. 3. A dimming signal output circuit for providing a dimming signal corresponding to a dimming amount instructed using the transmission signal to a dimmer for adjusting a light output of an illumination load serving as a load, 3. The terminal of the remote monitoring and control system according to claim 1, wherein a voltage output is used as a power supply of the dimming signal output circuit.