JPS625560Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a combustion control device, and particularly to a combustion control device that controls a combustion device including a burner and the like.

Conventionally, in the case of combustion control devices that control combustion equipment equipped with burners, etc., keep relays have been used in the abnormality alarm protection circuit of the combustion equipment, so power outages may occur during abnormality alarms. In this case, the state before the power outage was maintained, and the burner was prevented from being automatically reignited when the power went out. However, the keep relay has disadvantages in that it is larger and more expensive than other electronic components of the combustion control device. Additionally, if a power outage occurs during normal operation, no special protection circuitry is provided and the sequence proceeds so that the burner is automatically reignited when the power outage returns. However, in such a case, there is a possibility that unburned gas may have accumulated inside the burner, posing a risk of explosion.

This invention eliminates the shortcomings of the conventional combustion control device mentioned above, and without using an expensive keep relay, the burner automatically operates not only during a power outage during an abnormal alarm, but also during a power outage during normal operation. An object of the present invention is to provide a combustion control device that can suppress re-ignition.

This invention can be summarized as follows: a relay that enables the combustion device to operate, a capacitor that is directly charged by the power source, a switch that is connected to the power source, and a holding type that is connected to the non-power side of the switch. Combustion control comprising a switching element, a switching element control circuit that controls the holding type switching element according to the charging voltage of the capacitor, and a relay control circuit that controls the relay according to a signal from the holding type switching element. It is a device.

Hereinafter, embodiments of this invention will be described based on the drawings.

FIG. 1 is a circuit diagram showing an embodiment of this invention. AC power is input to AC power input terminals 1 and 2. Input terminals 41 and 42 of the transformer 4 are connected to the AC power input terminals 1 and 2. AC input terminals 51 and 52 of the diode bridge 5 are connected to output terminals 43 and 44 of the transformer 4. The + output terminal 53 of the diode bridge 5 is connected to one terminal of the resistor 6 and the power supply side contact 25a of the switch 25. The other terminal of the resistor 6 is connected to one terminal of a resistor 7, one terminal of a capacitor 8, and the cathode of a Zener diode 9. The other terminal of the resistor 7 and the other terminal of the capacitor 8 are connected to the negative output terminal 54 of the diode bridge 5.
The base of a transistor 10 is connected to the anode of the Zener diode 9. The emitter of transistor 10 is connected to -output terminal 54. The collector of transistor 10 is connected to one terminal of resistor 11, one terminal of resistor 12, and the base of transistor 13. The other terminal of the resistor 11 is connected to the non-power supply side contact 25b of the switch 25. The other terminal of resistor 12 is connected to -output terminal 54. The emitter of transistor 13 is connected to -output terminal 54. The collector of transistor 13 is resistor 1
Connected to one terminal of 4. The other terminal of the resistor 14 is the non-power supply side contact 25b of the switch 25.
It is connected to the. The collector of the transistor 13 has a gate G of a programmable union transistor (hereinafter referred to as PUT) 15.
is connected. Anode A of PUT 15 is connected to non-power supply side contact 25b of switch 25. The cathode K of PUT15 is the transistor 1
It is connected to the base of 6. transistor 16
The emitter of is connected to the - output terminal 54.
The collector of transistor 16 is connected to one terminal of resistor 17, one terminal of resistor 18, and the base of transistor 20. Resistor 17
The other terminal is the non-power side contact 25 of the switch 25.
connected to b. The other terminal of resistor 18 is connected to -output terminal 54 via capacitor 19. The emitter of transistor 20 is connected to -output terminal 54. transistor 20
The collector of is connected to one terminal of the relay 21. The other terminal of the relay 21 is the switch 25
It is connected to the non-power supply side contact 25b of. A safety switch circuit 22 and a flame detection circuit 23 are connected between the non-power side contact 25b of the switch 25 and the negative output terminal 54 of the diode bridge 5. Furthermore, the output section of the safety switch circuit 22 is
Connected to gate G of PUT15. The output of the flame detection circuit 23 is connected to the safety switch circuit 22. One terminal of the contact 21a of the relay 21 is connected to the AC power input terminal 1. The other terminal of the contact 21a is connected to one terminal of the combustion device 3. The other terminal of the combustion device 3 is connected to the AC power input terminal 2. The combustion device 3 includes an ignition transformer 31 and a gas electric valve 32. One terminal of the contact 21b of the relay 21 is connected to the non-power supply side contact 25b of the switch 25. One terminal of the alarm lamp 24 is connected to the other terminal of the contact 21b of the relay 21. The other terminal of the alarm lamp 24 is connected to the - output terminal 54.

Next, the operation of the circuit shown in FIG. 1 will be explained in terms of normal ignition mode, ignition failure mode, and power outage mode.

First, the normal ignition mode will be explained. When AC power is supplied to AC power input terminals 1 and 2, the power is transformed to an appropriate voltage by a transformer 4 and applied to a diode bridge 5. The diode bridge 5 rectifies the input AC power and supplies the positive DC power to the + output terminal 53 and the negative DC power to the - output terminal 54. The DC power source is voltage-divided by a resistor 6 and a resistor 7 and inputted to a capacitor 8.
Capacitor 8 is charged. When the charging voltage of capacitor 8 exceeds a certain value, Zener diode 9
operates, a constant voltage is applied to the base of transistor 10, and transistor 10 is in a state where it can be turned on. When a person turns on the switch 25 in this state, the DC power voltage divided by the resistors 11 and 12 is applied to the collector of the transistor 10, and the transistor 10 is turned on. As a result, the potential of the base of the transistor 13 becomes 0, and the transistor 13 is turned off. By the way, PUT15
is one of the holding type switching elements, and is turned on when the potential of the gate G becomes lower than the potential of the anode A. Once turned on, it remains on regardless of the potential of the gate G. To turn off the PUT 15, it is necessary to turn off the power supply itself between the anode A and the cathode K. A similar operation can be performed with a thyristor. Therefore, PUT
15 may be a thyristor. Now, since the transistor 13 is off, no current flows through the resistor 14, so the potential of the gate G of PUT15 and the potential of the anode A are the same, and the potential of the gate G of PUT15 is the same.
5 is off. Since PUT 15 is off, transistor 16 is also off. When the transistor 16 is turned off, a DC power voltage divided by the resistor 17 and the resistor 18 is applied to the base of the transistor 20, and the transistor 20 is turned on. The relay 21 is turned on by turning on the transistor 20.
turns on. The contact 21a of the relay 21 is a contact that is normally off and turned on when the relay 21 is turned on. The contact 21b of the relay 21 is a contact that is normally on and turns off when the relay 21 is turned on. Therefore, when the relay 21 is turned on, the contact 21a is turned on, and the combustion device 3 becomes operable. That is, in the combustion device 3, the gas electromagnetic valve 32 operates to supply gas to the burner, and the ignition transformer 31 operates to ignite the burner. The ignition of the burner is detected by the flame detection circuit 23, which outputs a flame detection signal a to the safety switch circuit 22.
The operation of safety switch circuit 22 is inhibited. From then on, the combustion device 3 enters normal operation.

Next, the ignition failure mode will be explained. In the above normal ignition mode, the burner is ignited,
The operation of the safety switch circuit 22 is suppressed by the flame detection signal a, but if ignition fails and the burner is not ignited, the flame detection signal a is output from the flame detection circuit 23.
is not output, so the safety switch circuit 22
operates and outputs a stop signal b. This stop signal b
is supplied to the gate G of PUT15, and as a result,
The potential of the gate G becomes lower than the potential of the anode A, and the PUT 15 is turned on. When PUT 15 is turned on, transistor 16 is turned on. transistor 16
When turned on, the potential of the base of the transistor 20 becomes 0, and the transistor 20 is turned off. When transistor 20 is turned off, relay 21 is also turned off, contact 21a is turned off, and contact 21b is turned on. Contact 2
The operation of the combustion device 3 is stopped by turning off 1a. When the contact 21b is turned on, the alarm lamp 24 is turned on and ignition failure is displayed. In response to this, a person takes recovery measures such as removing unburned gas in the burner and turns off the switch 25. This results in
PUT15 is turned off. Then, by turning on the switch 25 again, the normal ignition mode can be started.

Finally, the power outage mode will be explained. First, when the switch 25 is off, the AC power input terminal 1,
When the AC power input to the capacitor 2 is interrupted, the electric charge stored in the capacitor 8 is discharged. Even when the power outage is restored, the capacitor 8 is only charged again, and since the switch 25 is turned off, the operation does not proceed thereafter. Next, when the switch 25 is on and there is a power outage, the capacitor 8 is discharged and the transistor 10, PUT 15, relay 21, etc. are all turned off, and the relay 2
1 contact 21a is also turned off, and the combustion device 3 stops operating. Subsequently, when the power is restored, transistor 13 is immediately turned on before capacitor 8 is charged and transistor 10 is turned on. transistor 13
When turned on, the potential of the gate G of the PUT 15 becomes lower than the potential of the anode A, and the PUT 15 is turned on. When PUT 14 is turned on, transistor 16 is also turned on, so that the potential at the base of transistor 20 becomes zero. Therefore, the transistor 20 is not turned on, the relay 21 is not turned on, and therefore the combustion device 3 does not perform an ignition operation on its own. In addition, the contact 21b is turned on due to the relay 21 being turned off, which causes the alarm lamp 24 to light up to indicate that the power has returned. Note that the capacitor 19 prevents the transistor 20 from turning on earlier than the turning on of the transistor 13, the PUT 15, and the transistor 16 when the power is restored. As can be seen from the above, there is no risk that unburned gas accumulated in the burner will be ignited due to a power outage and an explosion will occur. Next, after a certain amount of time has passed after the power is restored, charging of the capacitor 8 is completed, the Zener diode 9 operates, and the transistor 10 also operates, so that the potential at the base of the transistor 13 becomes 0 and the transistor 13 is turned off. Although the potential of the gate G and the potential of the anode A of the PUT 15 become equal when the transistor 13 is turned off,
Before that, the anode A and cathode K of PUT15
Since a current flows between the
PUT15 remains on. Therefore, as described above, the relay 21 is turned off, and the combustion device 3 does not perform an ignition operation on its own. To resume normal operation after the power outage is restored, it is similar to the case of returning from the ignition failure mode described above. All you have to do is turn on the switch 25 again afterwards.

As described above, according to this invention, since an expensive keep relay is not used, a combustion control device that is smaller and safer can be provided. Also,
Not only during a power outage during an abnormal alarm, but also during a power outage during normal operation, it is possible to prevent the burner from being automatically reignited when the power is restored.
This eliminates the risk of ignition of unburned gas in the burner and an explosion.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of this invention. In the figure, 4 is a transformer, 5 is a diode bridge, 8 is a capacitor, 10, 13, 16, 20
is a transistor, 15 is a programmable union transistor, 21 is a relay, 2
5 is a switch.

Claims (1)

[Claims for Utility Model Registration] (1) A combustion control device that controls a combustion device, comprising: a relay that enables the combustion device to operate; a power source; and a device that is connected to the power source and is directly charged by the power source. a capacitor connected to the power supply; a holding switching element connected to the non-power supply side of the switch; and a holding switching element connected to the capacitor and the holding switching element, the holding switching element connected to the non-power supply side of the switch. a switching control circuit that controls an element according to the charging voltage of the capacitor; and a relay control that is connected to the holding type switching element and the relay and controlling the relay according to a signal from the holding type switching element. A combustion control device comprising a circuit. (2) The combustion control device according to claim 1, wherein the holding type switching element is a programmable union transistor. (3) The combustion control device according to claim 1, wherein the holding type switching element is a thyristor.