JP3274735B2 - Power supply control circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an electric shutter device for automatically opening and closing a shutter, and stops the supply of power when an accessory device, such as a sensor or a brake circuit, causes an overcurrent due to a power short circuit or the like. It relates to a power supply control circuit.

[0002]

2. Description of the Related Art As an electric shutter device, a controller that drives and controls a motor to open and close a shutter and an operation device that inputs an operation of the shutter by an operation switch are connected by a two-wire signal line. In some devices, signal transmission is performed by time division multiplexing with an apparatus, and a controller controls opening and closing of a shutter according to an operation input of an operation switch.

In this type of electric shutter device, for example, a sensor for detecting an object to prevent a person or an object from being caught in the shutter when the shutter is closed, a brake circuit for applying a brake in driving the shutter, In many cases, a buzzer circuit or a display circuit for notifying is provided in the controller as an accessory. If an abnormal state such as overcurrent flows is left as it is in this type of accessory device, there is a problem that a power supply circuit for supplying power to each circuit is damaged and the shutter itself cannot be opened and closed.

Therefore, a power supply control circuit 20 for stopping the supply of power to the attached device when an abnormality occurs is provided.
This power supply control circuit 20 is shown in FIG. To the power supply line from the power supply circuit, a transistor to Q ₁ as a switching element for controlling the supply of power to the accessory device, the on transistor Q _1, a transistor Q ₂ for OFF control, the supply current to the accessories Current limiting resistor Rp, which detects an abnormality in the attached device from the voltage across the current limiting resistor Rp (such as overcurrent), and a transistor Q ₂ according to the abnormality detection state of the abnormality detection circuit 22. And a control circuit 21 for controlling ON and OFF of the control signal.

[0005] The power supply control circuit 20, for example, when an overcurrent flows in the accessory device to detect its state from the voltage across the resistor Rp, the transistor Q ₂ and the off control circuit 21 in that case it allows the transistor Q ₁ is turned off, to stop the supply of power to the accessory device. Here, after that, it is conceivable to keep the supply of power to the accessory device in a stopped state.However, if the operation of the accessory device is stopped in a transient abnormal state, a problem may occur on the contrary. is there. Therefore, the control circuit 21 for example, on a regular basis the transistor Q ₁ performs the supply of power to the auxiliary device, if I and recovery abnormal state time, certain power supply as a resume.

[0006]

However, if the intermittent control is performed by the control circuit 21 as described above, the control circuit 21
, And as a result, the configuration of the power supply control circuit 20 itself is complicated. The present invention has been made in view of the above points, and an object of the present invention is to provide a power supply control circuit having a simple circuit configuration.

[0007]

According to the first aspect of the present invention, in order to achieve the above object, the power supply to the accessory is controlled by turning on and off the power supply line which is inserted into a power supply line for supplying power to the accessory. A switching element to be connected, a current limiting resistor connected to the side connected to the accessory device rather than the switching element to limit a supply current to the accessory device, and a voltage divided at a connection point between the current limiting resistor and the switching element for reference. Comparing the voltage at the connection point and the reference voltage with the two voltage-dividing resistors that create the voltage, and when the voltage at the connection point is higher than the reference voltage, turns on the switching element and supplies power from the power supply circuit to the accessory device An on / off control circuit for connecting the switching device in parallel with the switching device, and supplying a minute current to an attached device via a current control resistor when the switching device is off, to switch the switching device And a detection current feed resistors to perform the abnormality detection operation for detecting the potential of the connection terminals by the comparator even when off.

More specifically, as set forth in claim 2, an npn-type transistor is used as a switching element, a bias resistor for turning on the transistor by applying a bias thereto, and a potential of a connection terminal of an attached device and a reference voltage. And the comparator that turns off the switching element by bypassing the bias current generated by the bias resistor when the potential of the connection terminal is low.

According to a third aspect of the present invention, a pnp-type transistor is used as a switching element, and an output inversion type comparator for comparing the potential of a connection terminal of an attached device with a reference voltage, and a base-emitter of a transistor. , And the second bias resistor connected between the base and the output of the comparator may constitute the on / off control circuit.

Further, a zener diode may be connected between the base of the transistor and the ground in order to make the power supply voltage supplied to the accessory equipment constant. An operation switch for individually opening and closing a plurality of shutters, an operation switch for collectively opening and closing a plurality of shutters, or an operation switch for collectively opening and closing the plurality of shutters according to claim 5 in order to improve operability when one or a plurality of controllers for individually opening and closing a plurality of shutters are provided. An electric shutter in which one or more operation switches for opening and closing only a plurality of arbitrary shutters are provided in an operation device, and a controller arbitrarily opens and closes a plurality of shutters in response to operation of these operation switches. You may apply to an apparatus.

[0011]

According to the first aspect of the present invention, by configuring the power supply control circuit as described above, it is possible to always detect the current flowing to the attached device without periodically turning on the switching element. Is achieved by supplying a minute current to the attached device via the current control resistor when the switching element is turned off with the detection current supply resistor connected in parallel with the switching element, thereby simplifying the circuit configuration.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 4, the electric shutter system according to the present embodiment includes a controller 1 that drives and controls a motor to open and close a shutter, and an operation device 2 that inputs an operation of the shutter using an operation switch. The device 2 is connected with a two-wire signal line L, and a controller 1
A signal is transmitted by time-division multiplexing between the controller and the operation device 2, and the opening and closing of the shutter is controlled in accordance with the operation of the operation switch.

The signal transmission by time division multiplexing between the controller 1 and the operating device 2 according to the present embodiment is based on the signal transmission system of the existing remote monitoring and control system. Therefore, a basic remote monitoring control system will be described first. The remote monitoring control system is shown in FIG.
, A load Z such as a lighting fixture, a switch for performing an operation input for controlling the operation of the load Z, a monitoring terminal C for monitoring the operation state of the switch, and a plurality of switches for controlling the operation of the load Z. Control terminal B, which is connected to the control terminal B and the monitoring terminal C by a two-wire signal line L and performs signal transmission by time division multiplexing between the control terminal B and the monitoring terminal C It is composed of the device A. In the case of FIG. 8, the switch is provided integrally with the monitoring terminal C.
In general, the central control unit A is housed together with the breaker BR and the like in an electric board F such as a distribution board.

A unique address is set for each of the control terminal B and the monitoring terminal C, and the central control unit A specifies each address of each control terminal B or the monitoring terminal C in the transmission signal, thereby controlling each control terminal. The terminal B or the monitoring terminal C is individually accessed, and a signal is transmitted between the control terminal B and the monitoring terminal C by time division multiplexing. Transmission signal V _S, as shown in FIG. 9, a start pulse ST indicating the start of transmission, the mode data MD indicating the type of transmission signal V _S, the destination terminal device B of the transmission signal V _S, specifying the C Address data AD, control data CD indicating the contents of the control command, transmission error detection data (for example, checksum data) added for checking transmission errors C
S, a return period WT provided for returning a signal from the terminals B and C to the central control unit A. This transmission signal V _S is transmitted as a multipolar (± 24 V) pulse width modulation signal.

When the central control unit A receives an operation input from the monitoring terminal C, the central control unit A creates control data CD indicating the instruction content of the operation control of the load Z based on the operation input and transmits the control data CD to the control terminal B. I do. The control terminal B is a central control unit A
Address data AD of the transmission signal V _S transmitted from a time when a match with its address, capture the control data CD of the transmission signal V _S. Then, monitoring data indicating the operation state of the load Z based on the control data CD is returned to the central control device A in synchronization with the return period WT. The above reply period WT
, The transmission signal V _S is maintained at a positive potential (+24 V), and the control terminal B makes the two-wire signal line L substantially short-circuited to the central controller A in the current mode for monitoring data. Make a reply.

Upon receiving the monitoring data, the central control unit A creates control data CD for displaying the operating state of the load Z on a display provided on the monitoring terminal C based on the monitoring data, and monitors the data. Send to terminal C. Similarly to the control terminal B, when the address data AD of the transmission signal V _S coincides with its own address, the monitoring terminal C displays the load Z on the display based on the control data CD of the transmission signal V _S. Displays the operating status. The display state of the display at this time is also returned to the central control unit A during the return period WT.

With the above processing, the central control unit A controls the operation of the load Z and simultaneously monitors the operation state of the load Z and the display state of the display unit. In this type of remote monitoring control system, the operations of a plurality of loads Z can be controlled collectively. For example, so-called group control in which a plurality of loads Z are turned on and off collectively, and so-called pattern control in which the plurality of loads Z are controlled to an operation state arbitrarily set by a user can be performed.

A data table indicating the correspondence between the switch for performing this type of operation and the load Z is stored in the central control unit A in advance, and the central control unit A performs control corresponding to the load Z based on the data table. The control transmission signal V _S is transmitted to the terminal B. When the load Z is under the jurisdiction of a plurality of control terminals B, rules set in advance for each control terminal B (for example, in order of address)
, The transmission signal V _S for control is sequentially transmitted.

In the above description, the operation of the load Z is started by the switch.
Although the explanation was for when force was applied, the operation of the switch
Until the transmission is performed, signal transmission is performed as follows. One
Mari is the so-called standby when the switch is not operated
Sometimes the transmission signal V_SMode data MD
Central control unit A cyclically transmits the dummy transmission signal set to
To the signal line L. Here, the dummy transfer
It is this kind of remote monitoring and control system that transmits the signal
Terminal devices B and C transmit the transmission signal V as described later. _SFrom
Source, the dummy transmission signal is always
Due to the need to transmit. This damage
-During the transmission period of the transmission signal, the operation status of the load Z and the display
May be monitored.

The operation of shifting from the above-mentioned standby state to the above-described operation of performing signal transmission with the terminals B and C will be described below. Request to perform the signal transmission, and transmits the synchronization with the start pulse ST of the dummy transmission signal terminal unit B, and interrupt pulse V _i shown in FIG. 9 (b) from C to the central control unit A. Since this type of interrupt request is mainly issued from the monitoring terminal C when the switch S is operated, the following description will be made on the case where the monitoring terminal C issues an interrupt request.

In the central control unit A which has received the interrupt request, the mode data MD is set to an address specifying mode for specifying the monitoring terminal C which has made the interrupt request, and the monitoring terminal C which has made the interrupt request is set to the address specifying mode. Identify. In this case,
There is also a method of individually performing polling for accessing each monitoring terminal C and specifying the interrupt request terminal C. However, in this embodiment, in order to quickly identify the interrupt request terminal C, the upper few bits of the address data are identified,
The monitoring terminal C that has made a group access to collectively access the plurality of monitoring terminals C as a group and made an interrupt request returns the remaining lower bits to the central control device A during the return period WT. A method of notifying the central control unit A that it has made an interrupt request is adopted.

When the monitoring terminal C which has issued the interrupt request is specified as described above, the central controller A specifies the monitoring terminal C which has issued the interrupt request by the address data and operates the switch S. The monitoring data indicating the status is returned. The central controller A that has received the monitoring data creates control data based on the monitoring data and transmits the control data to the control terminal B to which the load Z corresponding to the monitoring data is connected. The following operation is performed in the same manner as the above-described operation at the time of control. Then, when the above control is completed, the process returns to the standby state.

The configuration of an electric shutter system based on the above remote monitoring and control system will be described below. The controller 1 has a function as a central control device A of the remote monitoring and control system, and the operating device 2 has a function as a monitoring terminal C. The operating device 2 stops the operation by the opening operation switch SW ₂₁ for performing an operation input for opening the shutter, the closing operation switch SW ₂₃ for performing an operation input for closing the shutter, and the opening operation switch SW ₂₁ and the closing operation switch SW _23. the operation switch SW ₂₂ is provided.

The operating device 2 has a circuit configuration shown in FIG.
As shown, a signal input portion to which the signal line L is connected is provided.
The operation device 2 can be connected to the signal line L with no polarity.
Diode bridge DB₁And this diode bridge
DB₁From the full-wave rectified output of the transmission signal by
A power supply circuit 22 for generating a power supply for the circuit;
A receiving circuit 23 for receiving the transmission signal transmitted from the
Iod Bridge DB ₁The output terminal of
A reply circuit 24 for returning a signal to the controller 1;
C that performs signal processing that performs central functions as a terminal
A signal processing circuit 20 composed of a PU, and a signal processing circuit
Oscillator 25 for generating a reference clock for the operation of path 20
Reset the signal processing circuit 20 at the time of system startup, etc.
And a reset circuit 26 for resetting.

The operating device 2 is configured as described above because the signal transmission by time division multiplexing performed between the controller 1 and the operating device 2 is based on the signal transmission system of the existing remote monitoring and control system. Is used as a reference. The signal transmission method will be described briefly. The controller 1 always transmits a transmission signal composed of a multi-pole (± 24 V) pulse width modulation signal cyclically and synchronizes with a return period provided in the transmission signal. Then, the operation device 2 sends back monitoring data indicating the operation status of the operation switch.

In this system, since the number of the operation device 2 is one, a unique address is set in the operation device 2 as in a normal remote monitoring and control system, and the address data of the transmission signal is used as the transmission destination. It is not necessary to specify and access the operating device 2. However, when a plurality of operation devices 2 are used, a unique address is set for the operation device 2 and
It is also possible to specify the destination operation device 2 with the address data of the transmission signal so that it can be accessed. In addition, since the transmission signal is maintained at the positive potential (+24 V) during the reply period, the operating device 2 returns the monitoring data in a so-called current mode by setting the signal lines L to a substantially short-circuit state. The signal transmission in the situation where the shutter is opened and closed will be described in the description of the operation of the controller 1.

By the way, since this type of operation device 2 has a multiplex transmission function, the cost is relatively high. For this reason, when the opening and closing operation of the shutter can be performed by the plurality of operation devices 2, the cost increases. Therefore, in this embodiment, in order to improve the above-described point, an operating device including only an operating switch for performing opening / closing control of a shutter other than the operating device 2 (the operating device is distinguished from the operating device 2 in the following description) For this reason, the operation device 2 is provided with a connection portion for connecting the external operation device to the operation device 2, and the operation switches SW _{21 to} SW ₂₃ provided in the operation device 2 in response to an operation input from the external operation device.
The shutter opening / closing control can be performed in the same manner as described above.

[0028] In this embodiment, there is used a connector CN ₁ as a connection portion for connecting the external operation device. Note that this connector CN _1, the other input terminal of the operation signal from the external operation device is input, the external power source (e.g., AC24
A power supply terminal to which V) is supplied is provided. further,
The operation signal input from the connector CN _1, and the opening operation switch SW _21, an input circuit 28 which is applied to the input terminal of the stop operation switch SW _22, and closing operation signal processing circuit 20 of the switch SW _23, the input circuit 28 And a power supply circuit 29 for generating a power supply for the power supply.

The power supply circuit 29 includes a diode bridge DB
_TwoAnd smoothing capacitor C₁External power supply
Bridge Bridge DB_TwoAnd smoothing capacitor
C₁To create a power supply for the input circuit 28. Entering
The power circuit 28 includes three photocouplers PC₁~ PC_ThreeIn
And each photocoupler PC₁~ PC_ThreeLight emitting die
Ode and current limiting resistor R₁~ R_ThreePower through the above times
Applying the output voltage of the path 29 to the input terminal of the external operating device,
Photo coupler PC₁~ PC_ThreePhoto transistor
Between each input terminal of the signal processing circuit 20 and the ground.
Continued. The switch of the external operation device
TA CN ₁Connected between the input terminal of
You.

Now, a switch for opening the external operating device
Is turned on, the photocoupler PC ₁Light emitting diode
When the current flows through the light emitting diode,
The phototransistor is turned on, and the operation device 2 is opened.
Switch SW_{twenty one}The same open operation signal as when
Signal processing circuit 20. In addition, other external operations
When the switch of the device is operated, it stops in the same way.
Operation switch SW_{twenty two}And closing operation switch SW_{twenty three}Operate
Stop operation signal and closing operation signal
Input to the road 20. Therefore, using an external operation device,
Performing shutter opening / closing control in the same manner as the operating device 2
Can be.

[0031] Here, an operation input from the external operating device takes in an insulated state using the photocoupler PC ₁ to PC _3, impact operation device such as a photo-coupler PC ₁ to PC ₃ from the external operation device of the power supply short-circuit It does not exceed 2. Further, the circuit configuration including the input circuit 28 and the power supply circuit 29 has an advantage that a non-voltage contact signal can be captured.

As shown in FIG. 5, the controller 1
A transmission / reception circuit 12 for transmitting signals in a time-division multiplex manner to / from the operating device 2 via a signal line L, a motor control circuit 11 for controlling the operation of a motor M for opening and closing a shutter, and a commercial power supply (100 VAC) A power supply circuit 13 for creating a power supply for each circuit and a signal processing circuit 10 composed of a microcomputer that functions as a center of the controller 1 and performs signal processing are provided.

Although the controller 1 performs drive control in accordance with the rotation speed of the motor M and the opening / closing position of the shutter, as will be described in detail later, the encoder E for detecting the rotation speed of the motor M and the shutter are completely mounted. It is provided with a lower limit detection switch SW ₁ for detecting that closed. Also, in order to enable the motor M to be installed on either the left or right side of the shutter depending on the location where the shutter is installed,
The rotation direction switching switch SW ₂ is provided. That is, when the motor M is mounted on the left and right, the rotation direction and the opening / closing operation of the shutter are reversed, so that the signal processing circuit 10 can determine which side of the motor M is installed on the left or right. the rotation direction switching switch SW ₂ is provided.

Further, in the case of the present embodiment, a sensor S for detecting an object is provided in order to prevent a person or an object from being caught in the shutter when the shutter is closed. Also,
There is also provided a brake circuit for applying a brake to the opening and closing operation of the shutter, and a buzzer and an indicator for notifying the occurrence of an abnormality. The power supply circuit 1 is connected to the sensor S via the sensor power supply circuit 15.
3, power is supplied from the power supply circuit 13 to the auxiliary device 3 such as a brake circuit, a buzzer circuit, and a display circuit via the power supply control circuit 14 according to the present invention.

The operation of the controller 1 will be described below with reference to FIG. Note that the following description is made for a case where the operating device 2 includes a light emitting diode that indicates an open or closed operation. Assuming that the control data to open a shutter over the central controller A in response to the operation of the opening operation switch SW ₂₁ of the controller device 2 (opening operation signal) is given, the signal processing through the time signal transmitter 12 In response to the opening operation signal received by the section 10, the signal processing section 10 supplies a control signal for driving the motor M to open the shutter to the motor control circuit 11, as shown in FIG. . Thereby, the shutter is opened.

During the opening operation of the shutter, the signal processor 10 detects the number of revolutions of the motor M from the output of the encoder E, and the shutter is completely opened due to a decrease in the number of revolutions of the motor M. Is detected. Until the rotation speed of the motor M decreases to a certain value or more, monitor data (up signal) indicating that the shutter is open is returned to the central control device A. In response to the monitoring data at this time, the central control device A sends control data for turning on the light emitting diode for displaying the open operation to the operating device 2 to turn on the light emitting diode.

When the shutter is completely opened,
In other words, when the rotation speed of the motor M falls below a certain value,
The signal processing unit 10 controls the motor control circuit 11
Control signal for stopping the rotation of the motor. At this time, the signal processing unit 10 sends monitoring data (upper limit signal) indicating that the motor M has stopped to the central control unit A. Here, if the central control unit A polls each control terminal B at the time of transmitting the dummy transmission signal and monitors the operation state of the load Z, the rising signal indicating that the shutter is open will be as follows. When the controller 1 is accessed in a state where the shutter is completely opened without sending a reply to the central controller A, the upper limit signal indicating that the opening operation of the shutter is stopped is sent to the central controller A. You may reply. As another method, it is also possible to provide the controller 1 with a function of performing an interrupt process in the same manner as the monitoring terminal C, and to return an upper limit signal in the interrupt process when the shutter opening operation is stopped.

When the upper limit signal indicating the stop of the opening operation of the shutter is thus supplied to the central controller A, the central controller A instructs the operating device 2 to emit light for displaying the opening operation in accordance with the upper limit signal. The control data for turning off the diode is sent to turn off the light emitting diode. Conversely, when monitoring data indicates that the closing operation switch SW ₂₃ has been operated (closing operation signal) is returned from the operating unit 2 to the central control apparatus A closing operation of the shutter is performed. At this time, similarly to during the opening operation, a signal is transmitted through the central control unit A, and the monitoring data (down signal) indicating that the shutter is closed is used for displaying the closing operation of the operating device 2. Turn on the light emitting diode.

When the shutter is closed as described above, the sensor control circuit 15 supplies power from the power supply circuit 13 to the sensor S, and the sensor S starts object detection. The output indicating the object monitoring status of the sensor S is output from the signal processing unit 10.
Given to Further, even during the shutter closing operation, the signal processing unit 10 detects the number of rotations of the motor M from the output of the encoder E. Further, the signal processing unit 10 monitors the on lower limit detection switch SW _1, the off-state.

Here, the object detection by the sensor S and the detection of the number of revolutions of the motor M are for preventing a person or an object from being caught in the shutter during the closing operation of the shutter, and the shutter is completely closed. That is, the lower limit detection switch SW
Detection is made from the on and off states of ₁ . Now, for example, when an object is detected by the sensor S, or when the number of rotations of the motor M decreases to a predetermined value or more, or when both states occur simultaneously, the closing operation of the shutter is forcibly stopped. This prevents a person or object from being caught by the shutter. The shutter may be forcibly reversed from the closing operation to the opening operation.

When such an abnormality occurs, the signal processing unit 10 sends monitoring data (abnormal signal) indicating the occurrence of the abnormality to the central control unit A. At this time, the central control device A displays an abnormality by giving control data for alternately lighting the light emitting diodes of the operating device 2. Note that another display may be provided on the operation device 2 for displaying an abnormality.

Further, if the shutter lower limit detection switch SW ₁ is completely closed is detected, the closing operation of the shutter is stopped, turns off the light emitting diodes of the controller device 2. During the opening and closing of the shutter, the stop operation switch S
W ₂₂ is operated (stop operation signal is returned) Sometimes, the opening and closing operation of the shutter in the controller 1 is stopped, the monitoring data for turning off the light-emitting diode or light-emitting diodes of the controller device 2 (intermediate stop signal) Send back. Here, during the opening and closing, the stop operation switch SW
When the button ₂₂ is operated, a display indicating that the shutter is stopped in the intermediate state may be displayed. For example, the fact that the stop operation has been performed during the opening operation may be indicated by blinking of the light emitting diode, and the stop operation during the closing operation may be indicated by blinking of the light emitting diode.

In this type of electric shutter device, signal transmission between the controller 1 and the operation device 2 is performed in a time-division multiplex manner, so that two signal lines L for signal transmission can be used. That is, the number of signal lines wired between the controller 1 and the operation device 2 can be reduced. This has a particularly remarkable effect particularly when the operation device 2 includes a display for displaying an operation.

Next, the power supply control circuit according to the gist of the present invention will be described.
The road 14 will be described. Power supply control circuit of this embodiment
14 is a power supply line for supplying power to the accessory device 3
Power supply control to auxiliary equipment 3 by inserting and turning on and off
Transistor Q as a switching element for controlling
₁And this transistor Q₁Connect accessory device 3
Current that is connected to
Limiting resistor Rp, current limiting resistor Rp and transistor Q₁
Divide the voltage at the connection point with the reference voltage V_refCreate
Two voltage dividing resistors R₁, R_TwoAnd the transistor Q₁To
A bias resistor Rb that turns on with a bias and an accessory
The potential of the connection terminal of the device 3 and the reference voltage V_refAnd compare
When the potential of the connection terminal is low,
The transistor Q₁Turn off
Comparator CP₁And the transistor Q₁And parallel connection
Transistor Q₁Is turned off via the current control resistor Rp
To supply a small current to the accessory 3₁
When the comparator CP ₁Connection terminal potential
(Output potential)
And a flow supply resistance Rf. In other words, in the case of FIG.
Has an npn-type transistor as a switching element
Q₁And compare the voltage at the connection point with the reference voltage
When the voltage at the point is higher than the reference voltage, the transistor Q₁
To turn on the power supply circuit to
The on / off control circuit is connected to the base resistor Rb and the comparator.
Data CP₁It consists of.

FIG. 2 shows an equivalent circuit of the accessory device 3 in a normal state.
(A). At this time, the potential of the connection terminal is now higher than the reference voltage V _ref, the output of the comparator CP ₁ is a high level, the transistor Q ₁ is turned on by the base current supplied from the base resistance Rb. In FIG. 2, the accessory 3 is shown as a load resistance _RL . In this case, the voltage supplied from the power supply circuit 13 and Vd, when the base-emitter voltage of the transistor Q ₁ Vbe, the DC amplification factor and H _FE, current I supplied to the accessory device 3, I = ( Vd-Vbe) / (Rp + Rb / _HFE + _RL ).

FIG. 2B shows an equivalent circuit at the time of abnormality. At this time, for example, an overcurrent flows through the accessory device 3 to lower the output potential, and the output potential falls below the reference voltage _Vref . Therefore, the output of the comparator CP ₁ becomes the low level, by drawing the base current through base resistor Rb, the transistor Q ₁ is turned off. At this time, by supplying a minute current to the accessory device 3 via the resistor Rf, the comparator CP ₁
In an abnormal state, and if the abnormality is transient,
The power supply can be restarted immediately.

At this time, the current I supplied to the accessory 3
Assuming that R ₁ and R ₂ are sufficiently larger than Rp and _RL , I = Vd / (Rf + Rp + _RL ). In the power supply control circuit 14, the resistors R ₁ , R
_{2 and} a series circuit of a resistor Rp and a load resistor _RL connected in parallel in a so-called bridge circuit, the potential at the connection point between the resistors R ₁ and R ₂ , the resistor Rp and the load resistor _RL
And the potential at the connection point between the compared in a comparator CP _1,
An abnormality of the attached device 3 is detected.

When this point is expressed by an equation, R _L = Rp · R ₂ / R ₁ is in an equilibrium state.
₁ turns on and off. The load resistance _RL and current I at that time
Is shown in FIG. With the above configuration, an abnormality in the attached device 3 can be detected without performing intermittent control, and the circuit configuration can be simplified. Also, the transistor Q ₁
Since the on / off control conditions of the switch are uniquely determined, unstable operation such as oscillation does not occur. Further, since the so-called hysteresis operation is not performed as described above, abnormality can be detected with high sensitivity and at high speed. Also, as in the case where the recovery is intermittently detected at the time of abnormality, the transistor Q ₁
Since the intermittent operation is not performed, generation of noise can be reduced. Moreover, the attached device 3 is set by the resistance Rf.
The value of the current flowing to the accessory device 3 in the event of an abnormality can be set according to.

FIG. 10 shows the configuration of another power supply control circuit 14.
Shown in In the case of FIG. 10, a pnp-type transistor Q ₁ ′ is used as a switching element, an output inversion-type comparator CP ₁ ′ for comparing the potential of the connection terminal of the accessory 3 with the reference voltage _Vref , and a transistor Q _{1. 1} 'first bias resistor Rs connected between base and emitter
And the second bias resistor Rb connected between the base and the output of the comparator CP ₁ ′ constitute an on / off control circuit.

FIG. 11 shows an equivalent circuit when the accessory device 3 is normal and when it is abnormal. In the normal case of FIG. 11A, that is, when the output potential is high, the comparator C
When the output of P ₁ ′ becomes low level, the base potential of the transistor Q ₁ ′ becomes a divided voltage of the resistor Rs and the resistor Rb, whereby the transistor Q ₁ ′ is turned on and the power is supplied to the accessory device 3. Is done.

At this time, the current I supplied to the accessory 3
When the collector-emitter voltage of the transistor Q ₁ ′ is Vce, I = (Vd−Vce) / Rp + _RL . If abnormal, the comparator CP ₁ 'output goes high, transistor Q _1' the base potential of approximately the same as the input voltage Vd, the transistor Q ₁ 'is turned off. At this time, the current I is supplied to the accessory device 3 via the resistor Rf. The equivalent circuit at this time is the same as that of FIG. 1 as shown in FIG.
FIG. 12 shows the relationship between the load resistance _RL and the current I of the accessory 3 of this embodiment.

FIG. 13 shows still another configuration, which is basically the same as the circuit of FIG. 1, except that the transistor Q ₁
A Zener diode ZD is provided between the base and the ground, so that when the voltage input from the power supply circuit 13 is higher than the Zener voltage Vz (actually, Vz-Vbe), a power supply with a constant voltage is attached. This is supplied to the device 3.

That is, when the voltage input from the power supply circuit 13 is lower than the zener voltage Vz, the operation is similar to that of FIG. Also, if higher than the Zener voltage Vz, the potential at the connection point of the resistor Rp and the transistor Q ₁ is, therefore kept Vz-Vbe, the current I becomes I = (Vz-Vbe) / Rp + R L.

The power supply control circuit 14 has been described above, but it goes without saying that the technology of the present invention can be applied to the sensor power supply circuit 15. In this case, the transistors Q ₁ and Q ₁ ′ are turned on by the signal processing circuit 10 together with the comparators CP ₁ and CP ₁ ′.
When the shutter is closed by the signal processing circuit 10, control is performed so that power is not supplied to the sensor S.

[0055]

According to the first aspect of the present invention, as described above, a switching element which is inserted into a power supply line for supplying power to an accessory and controls power supply to the accessory by turning on and off the switching element. And a current limiting resistor connected to the side connected to the accessory device to limit the supply current to the accessory device, and two components for dividing a voltage at a connection point between the current limiting resistor and the switching element to create a reference voltage. A piezoresistor, an on / off control circuit that compares the voltage at the connection point with the reference voltage and turns on the switching element to supply power from the power supply circuit to the attached device when the voltage at the connection point is higher than the reference voltage; It is connected in parallel with the switching element and supplies a minute current to the attached device via the current control resistor when the switching element is off. Since it has a detection current supply resistor that performs an abnormality detection operation that detects the potential of the connection terminal, it is possible to always detect the current flowing to the attached device without periodically turning on the switching element. The detection operation can be achieved by supplying a small current to the attached device via the current control resistor when the switching element is turned off with the detection current supply resistor connected in parallel with the switching element, thereby simplifying the circuit configuration. it can. Moreover, in the present invention, a controller that drives and controls a motor to open and close a shutter and an operation device that inputs an operation of the shutter with an operation switch are connected by a two-wire signal line, and the controller and the operation device are connected to each other. Performs signal transmission by time division multiplexing, controls the controller to open and close the shutter according to the operation input of the operation switch, makes the transmission signal a multipolar signal, and connects it to the signal line with no polarity Since the means is based on the electric shutter device provided in the operating device, the signal line can be two-wire type, the number of wirings can be reduced, and the operating device can be connected to the signal line without polarity. There is also an advantage that the construction of the device becomes easy.

According to a fifth aspect of the present invention, there is provided an electric shutter device comprising one or a plurality of controllers for individually opening and closing a plurality of shutters, and an operation switch for individually opening and closing a plurality of shutters, an operation switch for collectively opening and closing the shutters, or an arbitrary switch. Since one or more operation switches among the operation switches for opening and closing only a plurality of shutters are provided, individual control, collective opening and closing control of a plurality of shutters, or only an arbitrary plurality of shutters are performed according to the operation of these operation switches. Can be controlled to open and close, thereby improving the usability. The present invention may be applied to such an electric shutter device.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention.

FIGS. 2A and 2B are equivalent circuit diagrams in a normal state and an abnormal state.

FIG. 3 is an explanatory diagram showing a relationship between a load resistance of an attached device and a current.

FIG. 4 is a system configuration diagram of the electric shutter device.

FIG. 5 is a block diagram illustrating a circuit configuration of a controller.

FIGS. 6A to 6C are explanatory diagrams of the operation of the controller.

FIG. 7 is a circuit diagram of the operating device.

FIG. 8 is a configuration diagram of a remote monitoring control system as a basis of the electric shutter system of the present invention.

FIG. 9 is an explanatory diagram of a transmission signal according to the embodiment.

FIG. 10 is a circuit diagram of another embodiment.

FIGS. 11A and 11B are equivalent circuit diagrams of a normal state and an abnormal state.

FIG. 12 is an explanatory diagram showing a relationship between a load resistance and an electric current of an attached device.

FIG. 13 is a circuit diagram of still another embodiment.

FIGS. 14A and 14B are equivalent circuit diagrams of a normal state and an abnormal state.

FIG. 15 is a circuit diagram of a conventional example.

[Explanation of symbols]

1 controller 2 operating system 14 power supply circuit L signal line M motor SW ₂₁ to SW ₂₃ operating switches Q _1, Q ₁ 'transistors CP _1, CP _1' comparator Rp, Rf, Rb, Rs, R 1, R 2 resistor

Claims (5)

(57) [Claims] A controller for driving and controlling a motor to open and close a shutter and an operating device for inputting an operation of the shutter by an operation switch are connected by a two-wire signal line, and a controller is connected between the controller and the operating device. Perform signal transmission by division multiplexing, let the controller open and close the shutter according to the operation input of the operation switch, and make the transmission signal a multipolar signal,
It is used in an electric shutter device provided with a non-polar means for enabling a non-polar connection to a signal line in an operation device, and supplies power from a power supply circuit to a device provided in addition to a shutter open / close drive control system. A power supply control circuit for controlling the supply, which is inserted into a power supply line for supplying power to the accessory device and controls the supply of power to the accessory device by turning on and off; A current limiting resistor that is connected to the side to which the power supply is connected and limits a supply current to the attached device; two voltage dividing resistors that divide a voltage at a connection point between the current limiting resistor and the switching element to create a reference voltage; The voltage at the connection point is compared with the reference voltage, and when the voltage at the connection point is higher than the reference voltage, the switching element is turned on to supply power from the power supply circuit to the attached device. An abnormal detection operation that connects a switching control circuit and a switching element in parallel, supplies a minute current to the attached device via a current control resistor when the switching element is off, and detects the potential of the connection terminal by a comparator even when the switching element is off. And a detection current supply resistor for performing a power supply control circuit. 2. The method according to claim 1, wherein an npn-type transistor is used as the switching element, and a bias resistance for turning on the transistor by applying a bias is compared with a potential of a connection terminal of the accessory and a reference voltage. 2. The power supply control circuit according to claim 1, wherein said on / off control circuit is constituted by a comparator for turning off a switching element by biasing a bias current generated by a bias resistor. 3. A pnp-type transistor as said switching element, an output inversion type comparator for comparing the potential of a connection terminal of an attached device with a reference voltage, and a first transistor connected between a base and an emitter of a transistor. 2. The power supply control circuit according to claim 1, wherein said on / off control circuit is constituted by a bias resistor and a second bias resistor connected between the base and an output of the comparator. 4. The power supply control circuit according to claim 2, wherein a zener diode is connected between the base of the transistor and the ground. 5. An operation switch for individually opening and closing a plurality of shutters, an operation switch for individually opening and closing a plurality of shutters, an operation switch for collectively opening and closing a plurality of shutters, or opening and closing only an arbitrary plurality of shutters. 3. The electric shutter device according to claim 2, wherein one or a plurality of operation switches among the operation switches are provided in the operation device, and the controller is operable to open and close the plurality of shutters arbitrarily according to the operation of the operation switches. A power supply control circuit as described.