JPH0220613Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a combustion control circuit that controls a combustion device such as a gas combustion device.

[Prior Art] Conventionally, for example, in a gas combustion device, a combustion control circuit has been provided with a safety circuit that detects an abnormal state and stops energization to a load composed of an ignition control relay, a gas supply pipe opening/closing solenoid, etc. There is. Note that in this control circuit, there are some circuit parts that do not stop energizing even in the event of an abnormality, and are reset (returned to the initial state) by stopping and starting power supply. moreover,
These circuits are usually connected with capacitors for smoothing, delay, etc.

[Problem to be solved by the invention] When the power switch is turned off under normal conditions, the charge in the smoothing and delay capacitor is discharged through the load, and even if the power switch is immediately turned on again, the charge in the capacitor is discharged. It is being discharged. Therefore, the circuit is reset and no malfunction occurs.

However, in the event of an abnormality, the capacitor's charge is not discharged through the above load, so when the power switch is turned off, the cause of the abnormality is removed, and the power is turned on again, if the capacitor's charge has not completely discharged, the circuit will be reset. This may cause malfunction.

The purpose of this invention is to quickly discharge the charge in the smoothing and delay capacitors, which accumulates when the power switch is closed when the combustion equipment is in an abnormal combustion state, in preparation for re-closing the power switch. The aim is to provide a combustion control circuit that can

[Means for Solving the Problems] In order to achieve the above object, the present invention requires a reset by stopping and starting power supply, and a first load connected with a capacitor for smoothing or delay, etc. It consists of a power switch that opens and closes the power supply circuit that electrically connects the load of 1 and the power supply, a relay for ignition control, a solenoid for opening and closing the gas supply pipe, etc.
A combustion control circuit comprising a second load that is connected to the first load when the combustion state of the combustion equipment is normal and is disconnected from the first load when the combustion equipment is abnormal; A configuration is adopted in which a capacitor discharging circuit is provided to increase the load on the capacitor when an abnormality occurs and to discharge the charge in the capacitor when the power switch is opened.

[Operation and effect of the invention] When the combustion state of the combustion equipment is abnormal, the connection between the first load and the second load constituted by the ignition control relay and the gas supply pipe opening/closing solenoid is cut off. Therefore, even if the power switch is opened, the charges in the smoothing and delay capacitors will be discharged only in the first load. However, in response to the disconnection, the load on the capacitor is increased and the capacitor's charge when the power switch is closed is discharged by the capacitor discharge circuit. Charging load or coming off. Next, when the cause of the abnormality is removed and the power switch is closed again, the first load to which the capacitor is connected will be in a reset state.

Therefore, the combustion control circuit of the present invention removes the charge in the smoothing and delay capacitors, which accumulates when the power switch is closed when the combustion equipment is in an abnormal combustion state, in preparation for re-closing the power switch. It can be discharged quickly.

[Example] Next, a combustion control circuit of the present invention will be explained based on an example shown in the drawings.

FIG. 1 is an electronic circuit diagram of one embodiment of the combustion control circuit of the present invention.

1 is a power supply circuit, 2 is an operating circuit, and the power supply circuit 1 includes a transformer 12 that changes the 100-volt AC power supply 11 supplied to ordinary homes to the voltage value used in the operating circuit 2, and the transformer 12 reduces the pressure. Alternatively, a rectifier circuit 13 that rectifies the boosted current is connected to bridge the positive current path 14 and the negative current path 15 of the rectifier circuit 13, and stably supplies the current rectified by the rectifier circuit to the operating circuit 2. A main switch (power switch) 17 is interposed between the AC power supply 11 and the transformer 12. The operating circuit 2 detects the combustion state of a first load 21 connected to the positive current circuit 14 and the negative current path 15, and a gas combustion device (not shown), and outputs LOW when it is in a normal state, and outputs LOW when it is in an abnormal state (e.g. gas combustion equipment). The comparator 22 of the detection circuit A outputs Hi when there is a shortage of gas, an excess of gas, a lack of oxygen, etc., and the output of the comparator 22 controls the ignition of gas only when the gas combustion equipment is in a normal state. ignition control circuit 23 including a relay for
4. A PNP type transistor 27 that energizes a second load 26 equipped with a light emitting diode 25 etc. that indicates combustion of gas, and a PNP transistor 27 that energizes the second load 26, which is equipped with a light emitting diode 25 indicating gas combustion, and the second 1
A capacitor discharging circuit 3 conducts the positive current path 14 and the negative current path 15 of the load 21. On the input side of the comparator 22, there is a circuit that prevents the comparator 22 from outputting Hi due to malfunction.
A delay capacitor 28 is provided to achieve this, and one side of the comparator 22 and the capacitor 28 are connected to the positive current path 14 via a diode 29.

The capacitor discharge circuit 3 includes a base 30B connected to the output side of the comparator 22 via a diode 31, a collector 30C connected to the positive current path 14, and an emitter 30E connected to the negative current path 15. An NPN transistor 30, which is a switching element,
The capacitors 16 and 2 are connected between the collector 30C of the transistor 30 and the positive current path 14.
The diode 31 and the transistor 30
between the base 30B of the resistor 33, and between the diode 31 and the resistor 33 and the positive current path 1.
A resistor 34 is interposed between the output side of the comparator 22 and the diode 31, and a resistor 35 is interposed between the base 27B of the transistor 27 and the output side of the comparator 22, respectively.

The operation of the above configuration is such that when the main switch 17 is turned on, the AC power supply 11 is supplied to the power supply circuit 1, and a constant voltage DC current is generated between the positive current path 14 and the negative current path 15.

When the operating circuit is operating normally, the comparator 22
To generate a LOW output, the voltage at the base 27B of the transistor 27 decreases, and the transistor 27
The ON state is reached, and a positive current is supplied to the second load 26, and the solenoid 24 is energized. At this time, the base 30 of the transistor 30 passes through the resistor 34.
The current supplied to B is determined by the comparator 22.
Since we want to generate a LOW output, diode 3
Since the signal is canceled by the comparator 22 via the transistor 1, the transistor 30 becomes OFF, and no electrical conduction path is formed via the transistor 30 and the resistor 32.

When an abnormal state of the combustion equipment is detected, the output is delayed for a certain period of time by the capacitor 28, and then the comparator 22 generates a Hi output. Therefore, the voltage at the base 27B of the transistor 27 rises, turning the transistor 27 into an OFF state, de-energizing the second load 26, and stopping gas combustion. When restarting the operation and performing gas combustion again, the main switch 17 is manually turned off to stop the supply of current from the power supply circuit 1. As a result, the electric charges held by the capacitors 16 and 28 are applied to the base 30B of the transistor 30 via the resistors 34 and 33, and the transistor 30 is turned on. A current conduction path is formed through the resistor 32. As a result, the capacitor 16,
28 charges pass through the positive current path 14, the resistor 32, and the negative current path 15 via the transistor 30.
flows to Since the capacitor 28 is forced to discharge,
The reset time when re-operating can be shortened. In the above embodiment, the electric charges in the capacitor 16 of the power supply circuit 1 and the capacitor 28 of the detection circuit A are discharged by the operation of the capacitor discharge circuit 3, but
By using the capacitor discharge circuit 3 of the present invention, it is possible to quickly discharge the electric charge of all the capacitors (including the timer time setting capacitor, etc.) of the combustion control circuit that are discharged by the capacitor discharge circuit.

[Brief explanation of the drawing]

FIG. 1 is an electronic circuit diagram showing the operation of the combustion control circuit of the present invention. In the figure, 1...power supply circuit, 3...capacitor discharge circuit, 16...capacitor (smoothing capacitor),
17... Main switch (power switch), 21
...First load, 23...Ignition control circuit (ignition control relay), 24...Solenoid (gas supply pipe opening/closing solenoid), 26...Second load, 28
...Capacitor (delay capacitor).

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A first load that requires reset by stopping and starting power supply and is connected with a capacitor for smoothing, delay, etc., and a power source that electrically connects the first load and the power source. It consists of a power switch that opens and closes the circuit, a relay for ignition control, a solenoid for opening and closing the gas supply pipe, etc. It is connected to the first load when the combustion condition of the combustion equipment is normal, and is connected to the first load when there is an abnormality. The second connection is broken.
A combustion control circuit comprising: a capacitor discharging circuit for increasing the load on the capacitor when the combustion condition of the combustion equipment is abnormal, and discharging the charge on the capacitor when the power switch is opened; A combustion control circuit characterized by being provided. 2. Utility model registration claim 1, characterized in that the capacitor discharge circuit has a transistor that is turned on and off by the output of a detection circuit that detects the combustion state of the combustion equipment and outputs an output when an abnormal state occurs. Combustion control circuit as described in section. 3. The combustion control circuit according to claim 1 or 2, wherein in the capacitor discharge circuit, the degree of discharge is determined by a resistor.