JP2003032919A - Control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control circuit, relating to a control device for controlling a switch gear, capable of maintaining a prescribed condition by pulse which can surely drive a switch part by a constitution at a low cost, further more with small power consumption. SOLUTION: Drive voltage of a switch gear is detected, the duty ratio or amplitude or the period of a pulse waveform supplied to the switch gear of relay or the like in accordance with the detected drive voltage is controlled, and the switch gear is driven at the rated voltage. When a prescribed time passes after the switch gear is turned on, the pulse waveform supplied to the switch gear is adjusted so as to generate voltage for holding a condition of the switch gear in the prescribed condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device, and more particularly to a control device for controlling a switch device that can maintain a predetermined state by pulse driving.

[0002]

2. Description of the Related Art Currently, control systems using relays are used in various fields such as control systems and communication systems. Here, an example of a control system using a relay will be described.

FIG. 1 is a system block diagram showing an example of a conventional control system.

A control system 1 shown in FIG. 1 is a control system for controlling a heater and is connected to an AC power source 2 and driven by electric power from the AC power source 2 to perform various controls.

The control system 1 includes a fuel pump 11, an ignition device 12, a combustion blower 13, a warm air blower 14, and a relay 1.
5-18, power supply circuit 19, stabilized power supply circuit 20, sensor 21, operation panel 22, control device 23, display device 24,
The relay drive control transistors Q1 to Q4 are included.

The fuel pump 11 is a pump for pumping fuel to the combustion section. The ignition device 12 is a device that ignites fuel in the combustion unit. The combustion blower 13 is a blower for supplying air to the combustion section to burn the fuel. The warm air blower 14 is a blower for sending the air warmed by the heat generated in the combustion section to the outside.

The fuel pump 11, the ignition device 12, the combustion blower 13, and the warm air blower 14 are connected in parallel to the AC power supply 2 and driven by the AC power supply 2. At this time, the relay 15 is connected to the fuel pump 11. Relay 15
It is composed of a switch portion 15a and a relay coil 15b. The switch portion 15a of the relay 15 is connected in series to the fuel pump 11, and the operation is controlled according to the switching state of the switch portion 15a. Switch part 15a
Is turned on when a current is supplied to the relay coil 15b and a current flows through the relay coil 15b.
It is turned off in the state where no current is supplied to 5b and no magnetic field is generated. When the switch unit 15a is on, a current flows from the AC power supply 2 to the fuel pump 11, and the fuel pump 11 is operated. When the switch unit 15a is off, the supply of current from the AC power supply 2 to the fuel pump 11 is cut off, and the fuel pump 11 is stopped.

A relay 16 is connected to the ignition device 12. The relay 16 has a switch section 16 similar to the relay 15.
It is composed of a and a relay coil 16b. The switch 16a of the relay 16 is connected to the ignition device 12 in series, and its operation is controlled according to the switching state of the switch 16a. When the switch portion 16a is on, a current flows from the AC power supply 2 to the ignition device 12, and the ignition device 12 is operated. When the switch unit 16a is off, the supply of current from the AC power supply 2 to the ignition device 12 is cut off, and the ignition device 12 is stopped. Combustion blower 1
A relay 17 is connected to 3. The relay 17 has the same configuration as the relays 15 and 16, and includes a switch unit 17a and a relay coil 17b. The switch 17a of the relay 17 is connected in series to the combustion blower 13, and the operation is controlled according to the switching state of the switch 17a. When the switch 17a is on,
A current flows from the AC power supply 2 to the combustion blower 13, and the combustion blower 13 is operated. When the switch unit 17a is off, the supply of current from the AC power supply 2 to the combustion blower 13 is cut off, and the combustion blower 13 is stopped.

A relay 18 is connected to the warm air blower 14. The relay 18 has the same configuration as the relays 15 to 17, and includes a switch section 18a and a relay coil 18b.
It consists of and. The warm air blower 14 has a relay 1
8 switch units 18a are connected in series, and the switch unit 1
The operation is controlled according to the switching state of 8a. When the switch portion 18a is on, a current flows from the AC power supply 2 to the warm air blower 14, and the warm air blower 14 operates. When the switch portion 18a is off, the supply of current from the AC power supply 2 to the warm air blower 14 is cut off, and the warm air blower 14 is stopped.

Power from the AC power supply 2 is supplied to the power supply circuit 19. The power supply circuit 19 includes a transformer 19a,
Bridge diode circuit 19b, smoothing capacitor 19
It is composed of c. The AC power supply from the AC power supply 2
After being transformed by the transformer 19a, it is supplied to the bridge diode circuit 19b. Bridge diode circuit 1
9b rectifies the AC power source from the transformer 19b. The power source rectified by the bridge diode circuit 19b is smoothed by the smoothing capacitor 19c to be a DC power source.

The DC power from the power circuit 19 is supplied to the relay 1
It is used as a relay drive power source for driving 5 to 18 and is supplied to the stabilized power source circuit 20. The stabilized power supply circuit 20 stabilizes the DC power supply from the power supply circuit 19, and operates the operation panel 22, the control device 23, and the display device 24.
Etc.

The control device 23 is composed of a CPU and the like, and is supplied with operation information from the operation panel 22 and various detection signals from the sensor section 21. The sensor unit 21 supplies the control unit 23 with detection results of various states such as the combustion state of the combustion unit, room temperature, and flame detection. The operation panel 22 includes a power switch, a temperature setting switch, a timer setting unit, etc., and controls various setting information such as power on / off, set temperature, and timer time information.
Supply to.

The control device 23 controls the relays 15 to 18 based on the detection information from the sensor section 21 and the operation information from the operation panel 22.

For example, the control device 23 supplies relay drive signals to the relay drive control transistors Q1 to Q4 to the relays 15 to 18 in a predetermined sequence so that combustion is started when the power switch is turned on. .

When the relay drive signal is high level, the relay drive control transistors Q1 to Q4 are turned on, and when the relay drive signal is low level, the relay drive control transistors Q1 to Q4 are turned off. When the relay drive control transistor Q1 is turned on, the relay drive voltage is applied to the relay coils 15b to 18b. Relay coils 15b-18b
When the relay drive voltage is applied to the relay coil 15b
A current flows through ~ 18b. Relay coils 15b-18b
When a current flows through the relay coils, magnetic flux is generated in the relay coils 15b to 18b, and the magnetic flux acts on the switch portions 15a to 18a by the magnetic flux to turn on the switch portions 15a to 18a.

At this time, the relay 15 to the power supply circuit 19
The power supply voltage supplied to 18 is set near the rated voltage of the relay coils 15b to 18b so that the relays 15 to 18 operate reliably. When the relay drive control transistors Q1 to Q4 are turned on, the relay coil 15b
A rated voltage is applied to 18b.

[0017]

However, the conventional control device 23, when driving the relays 15 to 18, does not include the relay 1
In order to reliably turn on 5 to 18, relays 15 to 18
Had to be driven near the rated voltage of the relay coils 15b to 18b.

However, the AC power supply 2 not only supplies power to the power supply circuit 19, but also the fuel pump 11 and the ignition device 1.
2. Power is also supplied to the combustion blower 13 and the warm air blower 14. At this time, the fuel pump 11, the ignition device 12, the combustion blower 13, and the warm air blower 14 are turned on / off by the relays 15 to 18, so that the input of the power supply circuit 19 greatly changes. Therefore, the power supply circuit 19 may not be able to guarantee the rated voltage of the relay coils 15b to 18b. Therefore, it is necessary to increase the stability of the power supply circuit 19, which causes an increase in cost.

Further, when the fuel pump 11, the ignition device 12, the combustion blower 13, the warm air blower 14, etc. are continuously operated, the relay coils 15b-18b may be driven by the holding voltage of the relays 15-18. Nevertheless, since it is necessary to continue driving near the rated voltage, there is a problem that power consumption increases.

The present invention has been made in view of the above points, and an object of the present invention is to provide a control circuit which has an inexpensive structure and can reliably drive a switch portion with low power consumption.

[0021]

According to a first aspect of the present invention, a switch is detected while detecting a drive voltage of a switch device and controlling a pulse waveform supplied to a switch device such as a relay according to the detected drive voltage. Supply to the device.

In the second aspect, the duty ratio of the pulse is controlled according to the detected driving voltage.

According to the third aspect, the amplitude of the pulse is controlled according to the detected driving voltage.

According to a fourth aspect of the present invention, the pulse period is controlled according to the detected drive voltage.

According to the present invention, the pulse waveform supplied to the switch device is controlled so that the switch device is driven at the rated voltage.

According to a sixth aspect of the present invention, when a predetermined time elapses after the switch device is turned on, the pulse waveform supplied to the switch device is adjusted to a holding voltage for holding the state of the switch device in the predetermined state. To do.

According to the present invention, since the drive voltage can be controlled to a desired voltage by controlling the pulse waveform, the stability of the power supply circuit is not required, and the device can be manufactured at low cost.

Further, by controlling the duty ratio, amplitude, period, etc. of the pulse waveform in combination, accurate control becomes possible.

Further, according to the present invention, at the time of driving, it is possible to reduce the power consumption by driving with the rated voltage and then with the holding voltage which is a relatively low voltage.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows a system configuration diagram of an embodiment of the present invention. In the figure, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

The control system 100 of this embodiment has a power supply voltage monitoring circuit 101 and a control device 102.
The processing for controlling the relays 15 to 18 by the control system differs from that of the control system 1 shown in FIG.

The power supply voltage monitoring circuit 101 includes a power supply circuit 19
The power supply voltage from is detected.

FIG. 3 shows a circuit configuration diagram of a main part of an embodiment of the present invention.

The power supply voltage monitoring circuit 101 includes resistors R1 and R
2. It is composed of a Zener diode Dz. Resistance R
1, R2 are connected in series. The Zener diode Dz is connected in parallel with the resistor R2. Resistors R1 and R2
The power supply voltage from the power supply circuit 19 is applied to both ends of the series circuit. The voltage at the connection point between the resistors R1 and R2 is supplied to the control device 23 as the detection voltage of the power supply circuit 19.
The control device 23 controls the duty ratio of the relay drive pulse supplied to the relays 15 to 18 according to the detection voltage of the power supply voltage monitoring circuit 101.

FIG. 4 shows a flow chart of relay-on processing according to an embodiment of the present invention.

When the relay-on process occurs, the control device 102 firstly, in step S1, the power supply voltage monitoring circuit 101.
Read the power supply voltage detected in.

Next, in step S2, the cycle T0 and the duty ratio (on time ton / off time toff) of the relay drive pulse are determined based on the power supply voltage read from the power supply voltage monitoring circuit 101. The period T0 and the tea ratio are determined so that the relay drive voltage becomes a predetermined voltage, for example, a rated voltage.

FIG. 5 is a diagram for explaining a relay drive voltage according to an embodiment of the present invention. FIG. 5A is a diagram showing the relay drive pulse when the relay drive voltage is high, and FIG. 5B is a diagram showing the relay drive pulse when the relay drive voltage is low.

For example, when the relay driving voltage is high, the duty ratio of the relay driving pulse is made small as shown in FIG. 5A, that is, the relay driving pulse is set so that the period ton during which the current flows through the relays 15 to 18 becomes short. Control. Further, when the relay drive voltage is low, the duty ratio is increased as shown in FIG. 5B, that is, the relay drive pulse is controlled so that the period ton during which the current flows through the relays 15 to 18 is extended. At this time, the duty ratio is set such that the voltage applied to the relay coils 15b to 18b is about the rated voltage of the relay coils 15b to 18b.

Although the duty ratio of the relay driving pulse is changed in this embodiment, the present invention is not limited to this, and the amplitude of the relay driving pulse and the period T0 may be changed. Further, the voltage applied to the relay coils 15b to 18b may be controlled by combining the duty ratio, the amplitude, and the cycle.

Next, the control device 102 determines in step S3 whether or not a predetermined time has elapsed after driving. Step S3
If the predetermined time has not elapsed after driving in step S5,
Then, the relay drive pulse as shown in FIG. 5 determined in step S2 is supplied to the bases of the relay drive control transistors Q1 to Q4.

The relay drive pulse output from the control device 102 in step S5 is supplied to the relay drive control transistors Q1 to Q4. The relay drive control transistors Q1 to Q4 are turned on when the relay drive pulse has a high level, and turned off when the relay drive pulse has a low level. When the relay drive control transistors Q1 to Q4 are turned on, the relay coil 15
The power supply voltage from the power supply circuit 19 is applied to b to 18b. At this time, the voltage according to the relay drive pulse shown in FIG. 5 is supplied to the relay coils 15b-18b.

The relay coils 15b-18b are driven by a voltage according to the relay drive pulse and generate a magnetic flux. At this time, the switch portions 15a to 18a are turned on by the magnetic flux generated in the relay coils 15b to 18b with a voltage according to the duty ratio of the relay drive pulse.

The controller 102 determines in step S6 whether or not a relay-off command has been issued. Step S
If the relay-off command is not issued in step 6, the process returns to step S1 and steps S1 to S6 are repeated.

At this time, if it is determined in step S3 that a predetermined time has elapsed after driving, the duty ratio of the relay drive pulse is made smaller than the duty ratio determined in step S2 in step S4. That is, the relay coil 1
The duty ratio is adjusted so that the voltage applied to 5b to 18b becomes small. At this time, the duty ratio is
The voltage applied to the relay coils 15b to 18b is adjusted to be approximately the holding voltage of the relays 15 to 18. As a result, the relays 15 to 18 are driven at a relatively low voltage, and the power consumption can be reduced.

According to this embodiment, the drive voltage can be controlled to a desired voltage by controlling the pulse waveform.
Since the stability of the power supply circuit is not required, the device can be manufactured at low cost.

Further, by controlling the duty ratio, amplitude, period T, etc. of the pulse waveform in combination, accurate control becomes possible.

Further, according to the present invention, at the time of driving, it is possible to reduce power consumption by reliably driving at the rated voltage and then driving at the holding voltage which is a relatively low voltage.

According to this embodiment, the relay drive voltage for turning on the relays 15 to 18 is pulsed, and the duty ratio, amplitude, and cycle of this pulse are controlled according to the power supply voltage of the power supply circuit 19. Relay coil 15b
The voltage applied to 18b can be accurately adjusted to the rated voltage or the holding voltage. Therefore, the relay coils 15b to 18b can be accurately driven at the rated voltage or the holding voltage without stabilizing the output voltage of the power supply circuit 19.

[0050]

As described above, according to the present invention, since the drive voltage can be controlled to a desired voltage by controlling the pulse waveform, the stability of the power supply circuit is not required, so the device can be manufactured at low cost. It has features such as being able to.

Further, according to the present invention, it is possible to perform accurate control by controlling the duty ratio, the amplitude, the period, etc. of the pulse waveform in combination.

Further, according to the present invention, at the time of driving, it is possible to reduce power consumption by reliably driving at the rated voltage and then driving at the holding voltage which is a relatively low voltage.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of an example of a conventional control system.

FIG. 2 is a system configuration diagram of an embodiment of the present invention.

FIG. 3 is a circuit configuration diagram of a main part of an embodiment of the present invention.

FIG. 4 is a flowchart of relay-on processing by the control device.

FIG. 5 is a diagram for explaining a relay drive pulse.

[Explanation of symbols]

2 AC power supply 11 Fuel pump 12 Ignition device 13 Fuel blower 14 Warm air blower 15-18 relay 15a-18a switch section 15b-18b relay coil 19 Power circuit 20 Stabilized power supply circuit 21 Sensor part 22 Operation panel 23 Display 100 control system 101 Power supply voltage monitoring circuit 102 control device

Claims (6)

[Claims] 1. A control device for controlling a switch device for switching the supply of current to a load, comprising: a voltage detector for detecting a drive voltage of the switch device;
A control device comprising: a drive unit that supplies a pulse voltage to the switch device while controlling a pulse waveform to be supplied to the switch device according to a drive voltage detected by the voltage detection unit. 2. The control device according to claim 1, wherein the drive unit controls the duty ratio of the pulse according to the drive voltage detected by the voltage detection unit. 3. The control device according to claim 1, wherein the drive unit controls the amplitude of the pulse according to the drive voltage detected by the voltage detection unit. 4. The control device according to claim 1, wherein the drive unit controls the cycle of the pulse according to the drive voltage detected by the voltage detection unit. 5. The drive unit controls a pulse waveform supplied to the switch device so that the switch device is driven at a rated voltage, according to any one of claims 1 to 4. Control device. 6. The holding voltage for holding a state of the switch device in a predetermined state with a pulse waveform to be supplied to the switch device when a predetermined time has passed since the switch device was turned on. 6. The control device according to claim 1, wherein the control device is adjusted so that