JP2001245472A - Control circuit of electric apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability in the operation control of an electric apparatus. SOLUTION: An operation block 10 flows charging current to a secondary battery to detect output voltage to the secondary battery so as to be output as a monitor signal through a plurality of paths 5 and a drive block 20 regulates electric power for supplying to the operation block 10. A control circuit 1 outputs a control signal for controlling the operation of the drive block 20 on the basis of the monitor signal taken in from the operation block 10. Since the control circuit 1 is provided with the plurality of the paths 5 taking in the monitor signal, even when some path 5 fails, the monitor signal can be taken in to the control circuit 1 by the other normal path 5, and the improvement of reliability in the operation control of a charger.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control circuit to which a monitoring signal indicating a state of a monitoring target related to the operation of an electric device is input, and which controls the operation of the electric device according to the monitoring signal.

[0002]

2. Description of the Related Art Conventionally, a monitoring signal indicating a state of a monitoring target related to the operation of an electric device is input, and a charger for charging a secondary battery as a control circuit for controlling the operation of the electric device in accordance with the monitoring signal. There was a control circuit. The control circuit has a microcomputer as a main component, and controls a charging current to the secondary battery by detecting, for example, a voltage between both ends of the secondary battery.

[0003]

In the above-mentioned charger, for example, UL (Underwriters Laborato)
ries Inc.) When designing a charger whose output is limited to 100 W or less by the standard, the control circuit takes in the battery voltage of the secondary battery as a monitoring signal and controls the charging current so that the output is 100 W or less. There is a need. However, if the path through which the control circuit takes in the monitoring signal is accidentally or deliberately forced to stop, the output is set to 1
There is a problem that the charging current cannot be controlled to be equal to or less than 00 W, and the UL standard is not satisfied.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a control circuit for an electric device which can improve the reliability of operation control of the electric device.

[0005]

According to a first aspect of the present invention, in order to achieve the above object, a monitoring signal indicating a state of a monitoring target related to the operation of an electric device is input, and the electric device is responsive to the monitoring signal. A control circuit for controlling the operation of the control signal, characterized in that a plurality of paths for capturing the monitoring signal are provided, and even if any of the paths for capturing the monitoring signal fails, the monitoring signal is transmitted to the control circuit through another normal path. The reliability of the operation control of the electric device can be improved.

According to a second aspect of the present invention, in the first aspect of the present invention, the microcomputer which takes in the monitoring signal through the first path and the monitoring signals which take in through the second and subsequent paths each compare with a reference value. A plurality of comparators, and operation control means for controlling the operation of the electric device according to the monitoring signal from the microcomputer or any one of the comparators, wherein the microcomputer has a circuit compared to the comparator. Since the number can be reduced, the first method is used when it is necessary to set a plurality of thresholds for the monitoring target.
This is effective when the state of the monitoring target is determined based on the monitoring signal taken into the microcomputer by the path (2), and the second and subsequent paths for taking the monitoring signal through the comparator are used in an auxiliary manner.

According to a third aspect of the present invention, in the first aspect of the present invention, the analog monitoring signal captured by the first path
A microcomputer provided with an A / D converter for performing A / D conversion, and one or more input ports to which comparators for comparing the monitoring signals taken in the second and subsequent paths with reference values are connected. In a microcomputer, the number of circuits of an A / D converter is generally smaller than that of an input port. This is effective when the state of the monitoring target is determined based on the monitoring signal taken into the microcomputer by the route 1 and the input port to which the comparator is connected is used in an auxiliary manner.

According to a fourth aspect of the present invention, in the first aspect of the present invention, there is provided a microcomputer having a plurality of input ports connected to comparators for comparing the monitoring signals taken in the respective paths with reference values. With this feature, even when the microcomputer does not include an A / D converter or when the A / D converter of the microcomputer cannot be used for other signals, the reliability of operation control of the electric device can be improved.

According to a fifth aspect of the present invention, in the first aspect of the present invention, a priority is set for a plurality of paths, and when a monitoring signal is captured by a plurality of paths, the monitoring signal captured from a higher-level path is set. , And operation control means for controlling the operation of the electric device in accordance with the monitoring signal output from the priority determining means, between the monitoring signals taken in each path. Therefore, even if a difference occurs, the operation of the electric device can be controlled based on the monitoring signal having the higher priority, and occurrence of a malfunction can be prevented.

A sixth aspect of the present invention is characterized in that, in the fifth aspect of the present invention, the priority order determining means sets the priority order according to a level representing a state of a monitoring target.
The same operation as that of the fifth aspect is achieved.

The invention according to claim 7 is characterized in that, in the invention according to claim 5, at least the priority determination means comprises a microcomputer, and the priority is set by a signal processing procedure of the microcomputer. The circuit configuration can be simplified and the cost can be reduced as compared with the case where the means is configured by hardware.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment in which the present invention is applied to a control circuit of a charger for charging a secondary battery will be described in detail. However, the electric device according to the present invention is not limited to the charger, and the technical idea of the present invention can be applied to electric devices other than the charger.

(Embodiment 1) FIG. 1 is a main block diagram showing an electric apparatus (charger) of the present embodiment. The operation block 10 charges the secondary battery by supplying a charging current thereto, detects the output voltage to the secondary battery, and outputs it as a monitoring signal through a plurality of paths 5. The driving block 20 will be described later. In this way, the switching element Q1 is driven to adjust the power supplied to the operation block 10. Then, the control circuit 1 outputs a control signal for controlling the operation of the drive block 20 based on the monitoring signal fetched from the operation block 10.

FIG. 2 shows a circuit example of the charger of the present embodiment. This charger includes a series connection of an input power supply unit 30 for stepping down and rectifying a commercial AC power supply AC to a predetermined voltage and a rectified output of the input power supply unit 30 with a primary winding N1 of a transformer 31 and a switching element Q1 composed of a MOSFET. A current flowing through the primary winding N1 is interrupted at a high frequency by connecting the switching element Q1 with the oscillation output of the oscillation circuit 21 and a predetermined high-frequency voltage is generated in the secondary winding N2 of the transformer 31 by being connected to a circuit. And an inverter circuit section for rectifying the secondary output of the secondary winding N2 of the transformer 31 to recharge the secondary battery 40.
Rectifier circuit 11 and a plurality (two in this embodiment) of voltage dividing resistor circuits 1 for dividing the output voltage of rectifier circuit 11
2 _1, 12 and _2, captures one of the voltage dividing resistor circuit 12 ₁ in dividing the detected voltage (monitor signal) A / D conversion A / D
And converter 3, the comparator 4 is provided with an input port monitor signal indicating the comparison result between the external and detected voltage and the reference voltage Vr of the other resistor divider 12 ₂ is inputted, the control based on the monitoring signal A control circuit 1 including a microcomputer (hereinafter abbreviated as “microcomputer”) 2 for outputting a signal to an oscillation circuit 21 through a photocoupler 22;
And a control power supply circuit 32 for obtaining DC power supplied to the control circuit 1 from the secondary output of the control circuit 1. The oscillation circuit 21 controls the frequency and duty of the drive signal for switching the switching element Q 1 based on the control signal from the control circuit 1. The charge from the secondary battery 40 is controlled by changing the ratio and changing the output from the inverter circuit unit. The rectifier circuit 11 and the voltage dividing resistor circuits 12 ₁ and 12 ₂ correspond to the operation block 10 in the block diagram of FIG.
The inverter circuit unit including the switching element Q1 and the photocoupler 22 correspond to the drive block 20 in the block diagram of FIG.

The two voltage-dividing resistor circuits 12 ₁ and 12 ₂ are set to have substantially the same voltage-dividing ratio.
The detection voltage (monitoring signal) input to the converter 3 and the detection voltage input to the comparator 4 substantially match. The comparator 4 compares a preset reference voltage Vr with the detection voltage, and outputs a binary monitoring signal corresponding to the comparison result to the microcomputer 2.

The microcomputer 2 performs the following operation by executing software (program) stored in the internal memory. That is, the microcomputer 2 determines the state of charge of the secondary battery 40 based on the monitoring signal, and controls the drive block 20 by the control signal so as to fully charge the secondary battery 40 while preventing overcharge, and adjusts the charging current. At the same time, whether or not the output to the secondary battery 40 exceeds an upper limit value (for example, 100 W which is a limit value of UL standard) is monitored by a monitor signal, and driven by a control signal so as not to exceed the upper limit value. Block 20 is controlled. Note that the reference voltage of the comparator 4 is set so that the output to the secondary battery 40 corresponds to the upper limit, and the output of the comparator 4 is inverted when the output to the secondary battery 40 exceeds the upper limit. It is supposed to.

Here, the microcomputer 2 usually has an A / D converter 3
Block 2 based on the monitoring signal taken in via
0, but the path 5 ₁ to the A / D converter 3
If the detected voltage does not exceed the reference voltage Vr, the charging current is set to be substantially constant while the detected voltage does not exceed the reference voltage Vr. The drive block 20 is controlled so as to reduce or stop the current. A plurality of paths 5 ₁ to incorporate this manner the monitor signal, 5 ₂ control circuit 1
Since provided, either one path 5 ₁ (or 5 ₂₎ and the other path even longer be captured monitoring signals failed 5
₂ (or 5 ₁ ) to capture monitoring signals,
It is possible to improve the reliability of the operation control of the electric device (charger) by the control circuit 1.

Further, in this embodiment, an A / D converter for A / D converting an analog monitoring signal taken in by _one path 51 is used.
A converter 3 includes a microcomputer 2 which comparator 4 for comparing the monitoring signals received by the other path 5 ₂ with the reference voltage Vr is provided with a connected input port control circuit 1, the microcomputer 2 A Since the number of circuits of the / D converter 3 is generally smaller than that of the input port, when it is necessary to set a plurality of thresholds for the monitoring target (output voltage), one path 5 _This is effective when the status of the monitoring target is determined by the monitoring signal taken into the microcomputer 2 in ₁ and the input port to which the comparator 4 is connected is used in an auxiliary manner.

(Embodiment 2) FIG. 3 shows a block configuration of this embodiment, and FIG. 4 shows a specific circuit configuration. This embodiment processes the detection voltage input from the voltage dividing resistor circuit 12 ₁ digital monitor signal (monitor data) microcomputer 2
Is characterized in that the second microcomputer 6 for outputting to the input port is provided on one path 5 _1, the description thereof will be omitted with respect to other configurations and the basic operation is the same as the first embodiment.

The microcomputer 2 is usually obtained from the second microcomputer 6.
Drive block based on the monitoring signal (monitoring data)
Control of the second microcomputer 6,
Road 5 ₁If the fault occurs for some reason, the comparator
For example, based on the monitoring signal captured through
As long as the voltage does not exceed the reference voltage Vr, the charging current is substantially constant.
If the detected voltage exceeds the reference voltage Vr, the charging current is reduced.
Alternatively, the drive block 20 is controlled to stop.
Therefore, as in the first embodiment, one of the routes 5 ₁(or
Is 5_Two) Breaks down and the monitoring signal cannot be captured.
Route 5_Two(Or 5₁) Through the monitoring signal
The operation of the electric device (charger) by the control circuit 1
It is possible to improve the control reliability.

In this embodiment, one of the routes 5₁Superintendent
A second microcomputer 6 for capturing the visual signal and the other path 5_Two
Comparing the monitoring signal taken in with the reference voltage Vr
A comparator 4 for outputting the comparison result to the microcomputer 2
, The second microcomputer 6 is compared with the comparator 4
Since all the circuits can be reduced, the monitoring target (output power
Pressure), it is necessary to set multiple thresholds
In one path 5 ₁To be loaded into the second microcomputer 6
The status of the monitoring target is determined based on the monitoring signal
The other path 5 for taking in the monitoring signal via 4_TwoAncillary
This is effective when used for

(Embodiment 3) FIG. 5 shows a specific circuit configuration of this embodiment. This embodiment includes a comparator 4, 4 to be compared with each reference voltage Vr monitoring signals received by a plurality of paths 5 _1, 5 _2, a plurality of input ports having an output connected to the comparator 4,4 microcomputer The second embodiment is characterized in that it is provided with the other features and basic operations are the same as those of the first embodiment, and therefore description thereof is omitted.

Thus, in the control circuit 1 of the present embodiment, even when the microcomputer 2 does not have an A / D converter or the A / D converter of the microcomputer 2 cannot be used with other signals, the operation control of the charger is performed. Reliability can be improved.

(Embodiment 4) FIG. 6 shows a block configuration of this embodiment. In the present embodiment, a plurality of routes 5k (k = 1,
2,..., N), and when a monitoring signal is taken in each path 5, a priority judging means 7 for outputting a monitoring signal taken in from a higher-order path; 7 is characterized in that the microcomputer 2 is provided as an operation control means for controlling the operation of the electric device in accordance with the monitoring signal output from the controller 7. Description is omitted.

The priority determining means 7 comprises a switch of another input and single output such as a multiplexer. Among the monitoring signals fetched from a plurality of paths 5k in accordance with a preset priority, the higher priority path 5k is selected. Monitor signal 1
And outputs the selected one to the microcomputer 2. For example,
If index k number is prioritize higher in younger, priority determination means 7 if the path 5 ₁ the uppermost normally outputs a monitoring signal taken from the path 5 ₁ to the microcomputer 2 and, priority If this path 5 ₁ fails 2
And outputs a monitor signal taken from th path 5 ₂ to the microcomputer 2. Then, the microcomputer 2 outputs a control signal to the drive block 20 based on the monitoring signal as described in the first embodiment.

In the control circuit 1 according to the present embodiment, the priorities are set for the plurality of paths 5k, and when the monitoring signal is taken in each path 5, the monitoring signal taken from the upper path is set. With the output priority determination means 7,
Even if there is a difference between the monitoring signals taken in the respective paths 5k, the operation of the charger can be controlled based on the monitoring signal with the higher priority, and occurrence of a malfunction can be prevented.

When the priorities are set for the plurality of routes 5k, the priorities may be set according to the level indicating the state of the monitoring target. For example, as shown in FIG. 7, the detection range Sk (k
= 1, 2,..., N) as 0 to 5 V and 0 to 30 V, and the detection range Sk having a higher level (detection voltage) has priority over the path 5 k corresponding to the monitoring signal in each detection range Sk. set low rank, usually controls the operations of the charger takes in the monitor signals from the path 5 ₁ corresponding to the lower detection range S _1-level to the microcomputer 2, the path 5 for some reason
₁ backward path 5 ₂ in case of failure, it is sufficient to take in the monitor signal from ....

(Embodiment 5) In the above-described embodiment 4, the priority order judging means 7 is constituted by a switch. In this embodiment, the microcomputer 2 constitutes the priority order judging means, and the microcomputer 2 performs a signal processing procedure. The feature is that priority is set. Since the basic configuration and operation are common to the first embodiment, illustration and description of the common configuration will be omitted.

The microcomputer 2 included in the control circuit 1
Determines the priority of each route 5k according to the procedure shown in the flowchart of FIG. That is, the microcomputer 2 determines that each path 5k
Of the monitor signal (in case the detection voltage is equal to the reference voltage Vr) for the input port (or A / D converter 3) connected to
Is true if it exceeds, false if it does not)
Is determined, and if any of the monitoring signals is true, the secondary battery 40
A control signal is output to lower or stop the output voltage to the controller, and the process returns to the next processing cycle without judging the authenticity of the subsequent monitoring signals.

As described above, in the present embodiment, the priorities are set by the signal processing procedure (software) of the microcomputer 2, so that the priorities are determined in comparison with the case where the priority determining means is constituted by hardware as in the fourth embodiment. There is an advantage that the circuit configuration can be simplified and the cost can be reduced.

[0031]

According to a first aspect of the present invention, in the control circuit for receiving a monitoring signal indicating a state of a monitoring target related to the operation of an electric device and controlling the operation of the electric device in accordance with the monitoring signal, Multiple paths for capturing the monitoring signal, the monitoring signal can be captured to the control circuit via another normal path even if one of the paths for capturing the monitoring signal fails, improving the reliability of operation control of electrical equipment Can be achieved.

According to a second aspect of the present invention, in the first aspect of the present invention, the microcomputer which takes in the monitoring signal through the first path and the monitoring signals which take in through the second and subsequent paths each compare with the reference value. Since the microcomputer includes a plurality of comparators and operation control means for controlling the operation of the electric device in accordance with the monitoring signal from the microcomputer or any one of the comparators, the microcomputer has a smaller number of circuits than the comparators. Therefore, when it is necessary to set a plurality of thresholds for the monitoring target, the state of the monitoring target is determined by the monitoring signal taken into the microcomputer through the first path, and the monitoring signal is determined via the comparator. This is effective in the case where the second and subsequent routes that take in the data are used in an auxiliary manner.

According to a third aspect of the present invention, in the first aspect of the present invention, the analog monitoring signal captured by the first path
A microcomputer provided with an A / D converter for performing A / D conversion, and one or more input ports to which comparators for comparing the monitoring signals taken in the second and subsequent paths with reference values are connected. Therefore, in a microcomputer, the number of circuits of the A / D converter is generally smaller than that of the input port. Therefore, when it is necessary to set a plurality of thresholds for the monitoring target, the first path is used. This is effective when the state of the monitoring target is determined by the monitoring signal taken into the microcomputer and the input port to which the comparator is connected is used in an auxiliary manner.

According to a fourth aspect of the present invention, in the first aspect of the present invention, there is provided a microcomputer having a plurality of input ports connected to comparators for comparing the monitoring signals taken in the respective paths with reference values. Therefore, even when the microcomputer does not include the A / D converter or when the A / D converter of the microcomputer cannot be used for other signals, the reliability of the operation control of the electric device can be improved.

According to a fifth aspect of the present invention, in the first aspect of the present invention, a priority is set for a plurality of paths, and when a monitoring signal is captured by a plurality of paths, the monitoring signal captured from a higher-level path is set. And the operation control means for controlling the operation of the electric device in accordance with the monitoring signal output from the priority determining means, so that there is a difference between the monitoring signals taken in each path. Even if it occurs, the operation of the electric device can be controlled based on the monitoring signal having a higher priority, and occurrence of a malfunction can be prevented.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the priority order determining means sets the priority order according to a level indicating a state of a monitoring target. It works.

According to a seventh aspect of the present invention, in the fifth aspect of the present invention, at least the priority determining means comprises a microcomputer, and the priority is set by a signal processing procedure of the microcomputer. The circuit configuration can be simplified and the cost can be reduced as compared with the case of using hardware.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment.

FIG. 2 is a specific circuit diagram of the above.

FIG. 3 is a block diagram of a second embodiment.

FIG. 4 is a specific circuit diagram of the above.

FIG. 5 is a specific circuit diagram of a third embodiment.

FIG. 6 is a block diagram of a fourth embodiment.

FIG. 7 is an operation explanatory diagram of the above.

FIG. 8 is a flowchart for explaining the operation of the fifth embodiment.

[Description of Signs] 1 control circuit 2 microcomputer 3 A / D converter 4 comparator 5 path 10 operation block 20 drive block 40 secondary battery

Continued on the front page (72) Inventor Masaki Ikeda 1048 Kazuma Kadoma, Osaka Pref.Matsushita Electric Works, Ltd. 5H730 AA12 AA17 AS01 BB23 CC01 DD04 EE73 FD01 FF09 FF19 FG01

Claims (7)

[Claims] 1. A control circuit for receiving a monitoring signal indicating a state of a monitoring target related to the operation of an electric device, and controlling the operation of the electric device according to the monitoring signal, the control circuit including a plurality of paths for receiving the monitoring signal. A control circuit for an electric device, comprising: 2. A microcomputer for taking in a monitoring signal on a first path, one or more comparators for comparing each of the monitoring signals taken on second and subsequent paths with a reference value, and the microcomputer or any one of the comparators. 2. The control circuit according to claim 1, further comprising operation control means for controlling the operation of the electric device according to the monitoring signal from the comparator. 3. An A / D converter for A / D converting an analog monitoring signal taken in a first path, and a comparator for comparing each of the monitoring signals taken in a second and subsequent paths with a reference value. 2. The control circuit according to claim 1, further comprising a microcomputer including one or more input ports connected to the control circuit. 4. The electric apparatus according to claim 1, further comprising a microcomputer having a plurality of input ports connected to comparators each of which compares a monitor signal taken in each path with a reference value. Control circuit. 5. A method for setting priorities for a plurality of routes,
Priority determining means for outputting a monitoring signal fetched from a higher-order path when a monitoring signal is fetched in a plurality of paths, and controlling operation of the electric device in accordance with the monitoring signal output from the priority determining means The control circuit according to claim 1, further comprising an operation control unit. 6. The control circuit according to claim 5, wherein said priority order determining means sets said priority order according to a level indicating a state of a monitoring target. 7. The control circuit according to claim 5, wherein at least the priority determining means comprises a microcomputer, and the priority is set by a signal processing procedure of the microcomputer.