KR0121099B1 - Microcomputer control type heating device - Google Patents

Abstract

The microcomputer control mode heating device has a safety deciding condenser which is charged when a power plug is connected; a deciding circuit for deciding the amount charged of the safety deciding condenser and generating a heating stop signal if the amount charged is below a predetermined level; and a discharging circuit for discharging the safety deciding condenser, whereby even though a start signal is output from an operating switch when a microcomputer is reset, the heating source is maintained as a heating stop state if a heating stop signal is output from the deciding circuit, while the discharging circuit is maintained as an operating state if the heating stop signal is not output from the deciding circuit, and the discharging circuit is stopped when the operating switch is switched off.

Description

Microcomputer controlled heating device

1 is a circuit diagram illustrating an embodiment of the invention of claim 1.

2 is a flowchart for explaining the control operation of the invention according to claim 1;

3 is a circuit diagram illustrating an embodiment of the invention of claim 2.

4 is a flowchart for explaining the control operation of the invention according to claim 2;

* Explanation of symbols for the main parts of the drawings

6: microcomputer, 31: operation switch,

33: power plug, 34: safety judgment capacitor.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating apparatus such as a stove or a stove, and in particular, a heating apparatus of a type controlled by a microcomputer. The state is to be secured.

As a heating apparatus such as a stove of a type for controlling the heat generation operation of a heat generating source by a microcomputer, an abnormality detection circuit for monitoring the heat state of a heat generating source in which a heat generating source and a microcomputer for controlling the heat source are combined, and a power supply voltage to the microcomputer There is a switch consisting of a switch to start it.

In this heating apparatus, when the operation switch is turned on, a power supply voltage is applied to the microcomputer, and upon the application of the power supply voltage, the microcomputer starts to generate a heat source. When the abnormality detection circuit detects an abnormal operation of the heating source, the heating operation is forcibly stopped to ensure a safe state.

By the way, in the above-described heating apparatus, when the microcomputer malfunctions and becomes a reset state, in particular, when the apparatus is reset when the mechanism is abnormally stopped, the heating operation suddenly resumes, thereby failing to secure a safety state.

The problem is described in detail.

The microcomputer has a built-in supervisory circuit for managing its own operation, and the output of the circuit is output from a specific output terminal of the microcomputer. In a general mechanism controlled by a microcomputer, a reset circuit is provided for applying a reset signal to a reset input terminal when the supervisory circuit generates an abnormal signal. Therefore, if the microcomputer is reset due to noise or an abnormal signal from the monitoring circuit while an abnormal state occurs and the microcomputer keeps the mechanism in the forced stop state, the program counter becomes " 0 " and the microcomputer is restarted. Then, the microcomputer executes the command for generating the heat generating source again, and the forced stop mechanism becomes the heat generating state, making the safety state impossible.

The invention of claim 1 has been made in view of the above point, and has a function of inputting a start signal for starting a heat generation source to a microcomputer, and a type of operation switch in which the start signal is not lost even if the operation force is released. In the microcomputer control type heating apparatus equipped with the microcomputer control type heating device, when the reset signal is inputted to the microcomputer, the heating source can be kept in the heating stop state. The task is to avoid the risk of neglect.

The technical means of claim 1 to solve the above problem is, "The safety judgment capacitor charged when the power plug is connected, and the charging amount of the safety judgment capacitor is judged, and when the charge amount is below the reference level, the heating stop signal is If a heat generating stop signal is output from the judging circuit even if a start signal is output from the operation switch when the microcomputer is reset and the discharge circuit for discharging the safety judging capacitor is provided. If the heat generation stop signal is not output when the output of the determination circuit is judged, the discharge circuit is kept in an operating state and the discharge circuit is stopped when the operation switch is turned off. Will.

The technical means act as follows.

When the power supply voltage is applied to the heating device by connecting the power plug to the outlet, charging of the safety judgment capacitor starts, and when the charge continues and the charge amount reaches the reference level, a signal indicating this state is output from the determination circuit. The signal output from the judging circuit when the charge amount of the safety judgment capacitor is lower than the reference level is the heat generation stop signal described in the section of the technical means. After the safety judgment capacitor is charged to the reference level, the heat generation stop signal from the judgment circuit is lost. It is in the state that became.

When the start signal is output from the operation switch and the microcomputer starts to generate the heat source in the state where the charge amount of the safety determination circuit is equal to or lower than the reference level, the heat generation stop signal is not emitted from the determination circuit at this point. As in the conventional one, the heating is continued and the heating operation is continued.

On the other hand, according to the above technical means, when the stop signal is not output when the output of the determination circuit is judged, the discharge circuit is kept in the operating state. Therefore, after that, the determination circuit for monitoring the output of the safety judgment capacitor continuously outputs a heat generation stop signal (signal indicating that the safety judgment capacitor is in a discharged state).

When a reset signal is input to the reset input terminal due to abnormal operation or noise of the microcomputer in the above state where the heat generation stop signal is output from the safety judgment capacitor, the program counter of the microcomputer is reset to "0" and controlled. The program will be run again from scratch. At this point, however, the safety judgment capacitor is already in the discharge state and the determination circuit outputs the heat generation stop signal, so that the heat generation source is kept in the heat generation stop state when the microcomputer is restarted.

The invention of claim 1 has the following distinctive effects.

When the reset signal is input to the microcomputer, the heat generating source is kept in the heat generating stop state, so that even if the microcomputer resets during abnormal stop, the risk of leaving the heat generating source in the heat generating state can be avoided.

Next, the Example at the time of implementing this invention on the stove is demonstrated.

As shown in FIG. 1, a gas valve 11 is inserted into the gas circuit 10 of the gas burner 1 serving as a heat generating source, and an igniter 2 for igniting in the vicinity of the gas valve 1 is provided. And a flame detector 21 is provided.

The gas valve 11 or the like is controlled by the control circuit 3 in which the microcomputer 6 is combined, and the control circuit 3 is controlled by a seesaw type operating switch 31 in which the contact does not automatically return. Thus, electricity is supplied from the power supply circuit 32. That is, the power supply voltage is supplied to the microcomputer 6 or the other circuits combined with the control circuit 3 by the input of the operation switch 3l, and these start to operate. In addition, the output of the safety circuit 4 is applied to the control circuit 3, and the safety circuit 4 is a safety judgment capacitor 34 which is charged by the connection of the power plug 33, and the safety judgment. A discharge resistor 35 inserted into a circuit connected to the earth from the high potential side of the capacitor 34, a reference voltage setting circuit 36 for setting a reference voltage to be compared with the output of the safety judgment capacitor 34, and A comparator 37 for comparing the output of the reference voltage setting circuit 36 and the safety judgment capacitor 34, and a power supply capacitor 38 for applying a voltage to the comparator 37 and the like. In this embodiment, the set of the reference voltage setting circuit 36, the comparator 37, and the power supply capacitor 38 corresponds to the determination circuit described in the above-described technical means. Moreover, the combustion lamp 41 which receives electric power from the power supply circuit 32 is connected to the specific output port 39 of the microcomputer 6 which comprises the control circuit 3, and is connected with the said output port 39 The circuit between the combustion lamps 41 and the output of the safety judgment capacitor 34 are connected by a short circuit 43. The control program of the contents shown by the flowchart of FIG. 2 is input into the microcomputer 6, and the operation | movement of the stove which is an illustration embodiment is demonstrated according to the same figure below.

When the power plug 33 is connected to an outlet (not shown), charging of the safety judgment capacitor 34 starts, and when a predetermined charging time (about 1 second) elapses from the time of connection of the power plug 33, the safety judgment capacitor ( The output voltage of 34 is greater than the output voltage of the reference voltage setting circuit 36, and the "H" signal is output from the comparator 37.

When the operation switch 31 is turned on while the comparator 37 is outputting the "H" signal, a power supply voltage is applied to the microcomputer 6, and this starts to operate. The microcomputer 6 then executes step 80 of FIG. That is, when the output of the comparator 37 is checked and it is determined that this is just after the "H" signal is input and the operation switch 31 is put in, step 81 is executed to drive the igniter 2 and at the same time the gas is driven. The valve 1l is opened to start combustion of the gas burner 1. Next, at step 82, the output of the flame detector 21 is checked to confirm whether or not the gas burner 1 is extinguished. When the gas burner 1 is maintained in the combustion state, the igniter is kept in the OFF state in step 83 and an "L" signal is output to the output port 39. Then, a current flows from the power supply circuit 32 to the combustion lamp 41 to the output port 39, and the combustion lamp is turned on, indicating that the gas burner 1 is kept in the combustion state. When the output port 39 is in the "L" state, a current flows from the safety judgment capacitor 34 to the short circuit 43 to the output port 39, and the safety judgment capacitor 34 is discharged. From the comparator 37, the " L " In this embodiment, the circuit connected from the capacitor 34 to the short circuit 43 to the output port 39 corresponds to the discharge circuit described in the above-mentioned technical means.

Next, if the flame burner 21 detects a combustion abnormality because the gas burner 1 burns off the wind while the combustion continues, this is determined in step 84. By closing the gas valve 11, the gas burner 11 is kept in the extinguished state, and the combustion lamp 41 blinks (step 85). That is, the combustion lamp 41 flashes by alternately outputting the "H" signal and the "L" signal to the output port 39 of the microcomputer 6. At the time of blinking, the time width of the "L" signal is set larger than the time width of the "H" signal, whereby the output of the safety judgment capacitor 34 reaches the reference level (output of the reference voltage setting circuit 36). Do not rise until.

When the gas burner 1 stops abnormally while the gas burner 1 is in an extinguishing state, the reset IC 61 for monitoring the output of the monitoring terminal 63 by noise or the like operates to reset the terminal 64 of the microcomputer 6. If a reset signal is input to the control signal), the control operation returns to step 80. However, as described above, when the abnormal stop is performed, "L" which interlocks with the flashing of the combustion lamp 41 and the safety judgment capacitor 34 is kept in the discharged state and becomes the heat generation stop signal 80 from the comparator 7 Signal is output continuously. In this case, therefore, the control operation is shifted from step 80 to step 85 so that the gas valve 11 is kept closed and the combustion lamp 41 is kept flashing, thereby ensuring a safe state. . Then, when the reset signal enters the reset terminal 64 of the microcomputer 6, the steps 80 and 85 are repeated at that time, so that the gas burner 1 is maintained in the extinguishing state.

Next, in the stove according to the above embodiment, the gas burner 1 can be kept in the extinguished state when the power failure generated during combustion returns.

In other words, when a power failure occurs during the combustion of the gas burner 1, when electric charge remains in the safety judgment capacitor 34, it completely discharges through the discharge resistor 35. When the power failure returns from this state, the power supply from the operation switch 31 in the ON state is resumed and the microcomputer 6 is immediately operated. Since charging is in progress, its output does not rise to the reference voltage of the reference voltage setting circuit 36. Therefore, in such a case, when the microcomputer 6 is operated to execute step 80, the "L" signal, which becomes the heat generation stop signal, is output from the comparator 37, and in this case, the step 85 Is executed to control the gas valve 11 in the closed state. That is, after the electrostatic return, the gas burner 1 is kept in a digested state, thereby avoiding the risk of the gas burner 1 suddenly starting to burn after the electrostatic return.

In addition, although the gas burner 1 was employ | adopted in the said Example as a heat generating source, it cannot be overemphasized that an electric heater can be applied instead.

Moreover, in the said Example, although the case where this invention was implemented in the stove was demonstrated as an example, this invention is applicable also to heating apparatuses, such as a stove and a hot water heater.

In addition, in the above embodiment, a switch of a type in which the contact does not automatically return as the operation switch 31 is used. However, a return type switch may be used as long as a support circuit for maintaining the start signal is output. This is because the start signal is output by the support circuit even if the operation force applied to the return type switch is released.

The invention of claim 2 solves the same problem as the invention of claim 1.

The technical means according to claim 2 includes " a safety judgment capacitor discharged when the operation switch is turned OFF, a judgment circuit for judging the amount of charge of the safety judgment capacitor 34, and if it is equal to or higher than the reference level; A charging circuit for charging the safety judgment capacitor is provided, and if the heating stop signal is output from the determination circuit even when the start signal is output from the operation switch when the microcomputer is reset, the heating source is kept in the heating stop state. If the heat generation stop signal is not output when the output of the determination circuit is judged, the charging circuit is kept in an operating state.

The technical means act as follows.

When the power switch is connected to the outlet and the operation switch is turned on, the control of the heating source by the microcomputer is started. At this point, the safety judgment capacitor is not charged and the judgment circuit does not issue a heat generation stop signal. Therefore, in this case, the heat generating source is not maintained in the heat generating stop state, and the heat generating operation is started in the same manner as the conventional one described above.

On the other hand, according to the technical means, when the output of the determination circuit is judged that no heat generation stop signal is output, the charging circuit is operated to continuously charge the safety judgment capacitor, thereby monitoring the output of the safety judgment capacitor. The determination circuit continues to output the heat generation stop signal.

In this state, if the microcomputer malfunctions and becomes a reset state, when the microcomputer is restarted, the safety judgment capacitor is charged and a heat generation stop signal is output from the determination circuit. Is secured.

Next, the embodiment of claim 2 described above will be described with reference to FIGS. 3 and 4.

This charges the safety judgment capacitor 34 during operation of the microcomputer and discharges the safety judgment capacitor 34 at the time of the OFF switch operation. The same parts as are described with the same reference numerals.

This is so that electricity is supplied to the circuit of the power supply capacitor 38 or the comparator 37 via the charging transistor 30, and the operation switch is connected to the circuit connecting the output of the safety judgment capacitor 34 to earth. A discharge switch 311 is inserted in which 31 is mechanically interlocked to reverse the opening and closing operation with the operation switch 31.

Next, the operation | movement of the stove which is an Example is demonstrated according to the flowchart of FIG.

Even when the power plug 33 is connected to an outlet, the charging transistor 30 is kept in the OFF state before the insertion of the silver switch 31, whereby the safety judgment capacitor 34 is in the discharge state.

When the operation switch 31 is inserted, the discharge switch is kept in the OFF state in conjunction with this, and the microcomputer 6 starts the control operation of FIG. 4, and the output of the comparator 37 is first confirmed in step 90. do. In the case where the comparator 37, in which the safety judgment capacitor 34 is not charged to the reference level, emits the "L" signal (if it is determined that it is immediately after the operation switch 31 is input), in step 91 The igniter 2 is driven, the gas valve 11 is opened to start combustion of the gas burner 1, and the charging transistor 30 is kept in an ON state. Then, electricity is supplied to the power supply capacitor 38 to the safety judgment capacitor 34 to charge it. In this embodiment, the circuit connected from the charging transistor 30 to the safety judgment capacitor 34 corresponds to the charging circuit described in the above-mentioned technical means.

Next, in step 92 and 93, it is judged whether or not the gas burner 1 is ignited based on the signal of the flame detector 21, and when it is in the exothermic state, the combustion lamp 41 is turned on and Maintain combustion. In step 94, when the gas burr 1 enters into an abnormal state such as abnormal digestion, step 95 is executed to close the gas valve 11 and keep the combustion lamp 41 flashing. In addition, the charging transistor 30 is turned ON. In this state, when the reset IC 61 is operated to bring the microcomputer 6 into the reset state, the microcomputer 6 executes step 90 again. At this point, however, the safety judgment capacitor 34 is in the charged state, and the comparator 37 outputs the "H" signal (which in this embodiment becomes the heat generation stop signal), in which case the step 95 is repeated. To keep the gas burner 1 in an extinguished state.

In addition, it is possible to use an electric heater as a heat generating source, to apply the present invention to a heating apparatus such as a furnace or a hot water heater, and to be able to use a return type switch as the operation switch 31. Same as the example.

Claims (2)

A microcomputer-controlled heating device having a function of inputting a start signal for starting a heat generation source to a microcomputer and of operating switches of a type such that the start signal is not lost even when the operation force is released. The microcomputer is provided with a safety judgment capacitor which is charged at the time of connection, a judgment circuit which judges the amount of charge of the safety judgment capacitor, and when it is below the reference level, and generates a heat generation stop signal, and a discharge circuit which discharges the safety judgment capacitor. Even when the start signal is output from the operation switch at the time of reset, if the heat generation stop signal is output from the determination circuit, the heat generation source is kept in the heat generation stop state, and the heat generation stop signal is not output when the output of the determination circuit is judged. In the case of operating the discharge circuit In addition, the operation and maintenance Sikkim switch is OFF when the piece heating apparatus of a microcomputer-controlled so as to stop the discharge circuit. A microcomputer-controlled heating apparatus having a function of inputting a start signal for starting a heat generation source to a microcomputer and of operating a type in which the start signal is not lost even if the operating force is released. The microcomputer is provided with a safety judgment capacitor discharged at the time of OFF operation, a judgment circuit for judging the charge amount of the safety judgment capacitor and outputting a heat generation stop signal if it is above the reference level, and a charging circuit for charging the safety judgment capacitor. Even if the start signal is output from the operation switch when is reset, if the heat generation stop signal is output from the determination circuit, the heat generation source is kept in the heat generation stop state and the heat generation stop signal is not output when the output of the determination circuit is judged. If not, start the charging circuit. Microcomputer-controlled heating unit for maintaining the same state.