JPS58200926A - Control circuit for combustion - Google Patents

Abstract

PURPOSE:To improve safety through disconnection of a power source when a firing detecting circuit is brought to a trouble, by a method wherein, in case the firing detecting circuit detects a firing when a blower for combustion stops running, an operating relay is turned OFF. CONSTITUTION:A power source plug 1, a relay circuit 2 for controlling operations of a blower for combustion, an ignition transformer, etc., a DC power source 3 for circuit operation, a heater thermo circuit 4 for controlling temperature of a heater for evaporating fuel, a temperature control circuit 5, and a heat up memory circuit 6 are mounted. Further, a post purge circuit 7 for delaying and stopping a blower for combustion for a specified time in case combustion is brought to a stop, a combustion sequence circuit 8, a vibration detecting circuit 9 which performs an automatic fire-extinguishing caused by the occurrence of vibration, a firing detecting circuit 10, an oscillating circuit 11 for controlling a fuel feed quantity, and a pump driving circuit 12 are installed to form a circuit. This constitution causes the relay of the relay circuit 2 to be turned OFF if the firing detecting circuit 11 detects a firing when the blower for combustion stops running, and enables a power source to be disconnected when the firing detecting circuit 11 is brought to a trouble to secure safety.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion control circuit for a combustor used in a hot air heater or the like.

Conventionally, in this type of combustion control circuit, if the ignition detection circuit becomes abnormal, it may be assumed that ignition has been detected even though the combustion blower is stopped (unburned), and if it is, the ignition transformer will be activated. Because fuel was supplied before the ignition transformer operated, a violent explosion could occur in the combustion chamber if the ignition transformer operated, which was dangerous.

The present invention has been made in view of the above-mentioned points, and is intended to eliminate the above-mentioned disadvantages by having a configuration in which the power is cut off if the ignition detection circuit becomes abnormal.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 14. In the figure, 1 is a power plug connected to a commercial power supply, 2 is a relay circuit that controls the operation of the combustion blower and ignition transformer of the combustor, and 3 is a DC power supply that receives power from relay circuit 2 and operates the circuit. The power supply circuit that makes up the
4 is a heater thermo circuit that controls the temperature of the vaporization heater for vaporizing liquid fuel; 5 is a heater thermocircuit that controls the activation/stop of combustion and the amount of fuel to control the amount of combustion to maintain and control the room temperature constant; A temperature control circuit, 6 is a heat-up memory circuit that memorizes that the temperature of the vaporization heater has risen to a temperature that vaporizes the fuel, and 7 is a temperature control circuit that delays the combustion blower for a certain period of time when combustion has stopped. 8 is a sequence circuit that performs the combustion sequence; 9 is a vibration detection circuit for an earthquake-resistant automatic fire extinguishing system that detects vibrations exceeding a predetermined level such as an earthquake and stops combustion; 10 is a vibration detection circuit that detects the combustion pathology of the combustor. 11 is an oscillation circuit that controls the supply amount of liquid fuel; 12 is a pump drive circuit for driving a pump that feeds liquid fuel; 13 is a current fuse; 14 is a convection blower; 15 is a combustor. 16 is a relay coil 8 which will be described later.
Relay contacts 17 and 18 are power switches that switch according to the excitation state of 3 to change the output of the blower, and the power switch 17 maintains its state when turned on, while the power switch 18 closes only the moment it is turned on. . 19 is a relay contact that turns on and off in accordance with the excitation of a relay coil 146, which will be described later, and is connected in parallel to the power switch 18.
20 is a capacitor for noise absorption, 21 is a surge absorber, 22 is a terminal for connecting the t-source circuit 3 and relay circuit 2, 23 is a timer motor for automatic operation, 24 is a heater for vaporizing liquid fuel, 25 A relay contact is connected in series to the heater 24 to control the energization of the heater 24, and is turned on and off depending on the excitation state of a relay coil 57, which will be described later. 26 is a relay contact that turns on and off depending on the excitation state of a relay coil 115, which will be described later; 2T is a blower for supplying combustion air; and 28 is switched according to the excitation state of a relay coil 84, which will be described later, to control the output of the blower 27. 30 is a surge absorbing resistor and capacitor; 31 is a surge absorber; 32 is an ignition transformer; 33 is a relay contact that turns on and off in response to excitation of a relay coil 135, which will be described later, to control the ignition transformer 32; 34 is a terminal connecting the relay circuit 2 and the pump drive circuit 12; 35 is a power transformer; 36 is a terminal connected to a flame rod (not shown) for detecting flame current;
31 is a rectifier circuit consisting of a diode bridge, 38 is a smoothing capacitor, 39 ti resistor, 40 ti) transistor, 41 is a constant voltage diode, 42 is a capacitor, which together with the resistor 39, transistor 40, and constant voltage diode 41 supply a stabilized power supply. do. 43 is a relay power supply terminal for exciting each relay coil, 44 is a stabilized power supply terminal for other circuits, 45 is a ground terminal, 46 is a resistor, and 47 is attached to the vaporization heater 24 to detect the temperature of the vaporization heater 24. A high temperature thermistor 48 is a capacitor connected in parallel to the thermistor 47, 49.50 is a voltage dividing resistor, 51 is a capacitor connected in parallel to a resistor 50, and 52 is a resistor 46.
and the thermistor 4T to the inverted side, and the resistor 5
A comparator that receives a potential vb between 0 and 51 on the non-inverting side, a resistor and a diode interposed between the output of the 53.54Fi comparator 52 and the non-inverting input terminal,
55 and 56 are both diodes whose anodes are connected between the resistor 46 and thermistor 47, and 5T is the relay contact 25.
Comparator 52 is a relay coil that controls on/off.
is excited according to the output of When combustion is stopped by the temperature control circuit 5 connected in series with the 58Fi diode for canceling back electromotive force and the 59Fi diode 56V, that is, the comparator 8B
60 is a heat-up memory circuit 6 which selects whether to turn on or cut off electricity to the vaporizing heater 24 when the output is L.
and heater thermo circuit 4! & Connecting terminal, 61.62
is a terminal connecting the heater thermocircuit 4 and the temperature control circuit 5;
63 is a resistor, 64 is a diode whose cathode is connected to the terminal 61, 65 is an inverter consisting of a transistor array IC formed by incorporating several transistors into the same IC, and 66 is on/off controlled by the timer motor 23. Timer contacts, 67, 68, 69 are voltage dividing resistors connected in series between the power supply terminal 44 and the ground terminal 45, 70 is a variable resistor connected in parallel to the resistor 69, 7
1 is a capacitor, 72.74, 75.76 are power supply terminals 4
4 and the ground terminal 45, T3 is a resistor whose one end is connected between resistors 72 and 74 connected to the anode of the diode 64, and 77 is connected in parallel to the resistor 16. Thermistor for detecting room temperature, 78
is a resistor, 79 is a capacitor, 81 is an input terminal for the positive side of the capacitor 71 to the inverting side, and the positive side potential of the capacitor 78 to the non-inverting side. Salel comparator, 80U comparator 81 output terminal and non-inverting side input terminal. 82 is a resistor that connects the output terminal of the comparator 81 and the power supply terminal, 83 is a relay coil that switches and controls the FilJ relay contact 16, 84 is a 11J relay coil that switches and controls the relay contact 28, and 85 is a resistor that connects the output terminal of the comparator 81 and the power supply terminal. An inverter is interposed between the output terminal and the relay coils 83 and 84, 86 is a diode whose cathode is connected to the output terminal of the inverter 85, and 8T is the resistor T3 and the ground terminal 45.
A capacitor 88 is interposed between the capacitor 87 and
a comparator, 89u-1, into which the positive potential of the capacitor 71 is input to the non-inverting side, and the positive potential of the capacitor 71 is input to the inverting side;
a resistor connecting the output terminal of the comparator 88 and the non-inverting input terminal; 90 a resistor connecting the power supply terminal 44 and the output terminal of the comparator 88; 91 a terminal connecting the temperature control circuit 5 and the oscillation circuit 11; 92 is a terminal connecting the temperature control circuit 5 and the heat-up memory circuit 6; 93 is a diode whose cathode is connected to the terminal 60; 94 is a diode 93;
95 is a diode whose cathode is connected to the terminal 92, 96 is a resistor connected to the anode of the diode 95, 97 is a capacitor interposed between the resistor 96 and the ground terminal 45, 98 is a resistor connecting the power supply terminal 44 and the resistor 94, 99#- is a resistor, 1
A capacitor 101 connects the 0" um resistor 99 and the connection point of the resistor 98 and the resistor 96, and the anode of the capacitor 101 connects the resistor 96 and the resistor 9
P connected to the connection point of 8 and whose gate is connected to the resistor 99
UT, 102 is a diode whose anode is connected to the cathode of PUTlol and whose cathode is connected to the ground terminal 45, 103 is an inverter connected to the gate of PUT 101, and 104 connects the heat-up memory circuit 6 and the sequence circuit 8. Terminal, 1o5#i power supply terminal 44
106 is a diode whose anode is connected to the terminal 104, 10.7 is a resistor connected in parallel to the diode 106, and 108 is a resistor 101.
A capacitor 1 is interposed between the ground terminal 45 and the ground terminal 45.
o9 is a diode interposed between the cathode of the diode 106 and the power supply terminal 44, and is connected to the CR21 along with the resistors 105, 107, the diode 106, and the capacitor 108.
7 circuits are constructed. 110 and 111 are voltage dividing resistors, 11
3 is a capacitor connected in parallel to the resistor 110, 114
is a comparator that inputs the positive side potential of the capacitor 108 to the inverted side and the positive side of the capacitor 113 to the all non-inverted side, 112 is a resistor that connects the output terminal of the comparator 114 and the non-inverted side input terminal, and 115 is a relay contact. 26 is a relay coil that controls on/off control, and is interposed between the relay power supply terminal 43 and the output terminal of the comparator 114. 116 is a diode for canceling the back electromotive force of the relay coil 115, and 117 is a post purge circuit T and vibration detection circuit 9.
119 is a resistor connected to the terminal 104, and 120 and 121 are power supply terminals 4.
4 and the ground terminal 45, a voltage dividing resistor is connected in series with each other, 122 is a capacitor, 123t
A capacitor is connected in parallel to the i-resistance 121, 124 is a resistor connected to the positive side of the capacitor 123, 125 is a diode interposed between the capacitor 122 and the resistor 119, and 126 is connected to the anode of the diode 125. 127 is a comparator to which the positive terminal potential of the capacitor 122 is input to the non-inverting side, and the positive terminal potential of the capacitor 123 is input to the inverting side, 129H comparator 1
a resistor connecting the output terminal 27 and the power supply terminal 44;
9 is an inverter whose input is the output of the comparator 127; 130 is a diode interposed between the resistor 124 and the output terminal of the inverter 129; 131 is the inverter 12;
A diode whose cathode is connected to the output terminal of 9, 13
2 is a resistor that connects the power supply terminal 44 and the connection point between the resistor 126 and the anode of the diode 131; 133 is a diode that connects the resistor 119 and the power supply terminal 44; 134;
135 is a diode whose cathode is connected to the anode of the diode 133, and 135 is a relay coil that controls the relay contact 33 on and off.
29 output terminals. 133' is a diode whose anode is connected to the resistor 132;
19,120,121゜124.126,128,13
2. Capacitor 122.123. diode 125,1
30, 131, comparator 127 and inverter 12
When the ignition signal is not received from the ignition detection circuit 10 during the operation of the timer circuit described later, which is a main part of the present invention, the relay contact 19 is turned off, and the relay contact 19 is turned off when the ignition signal is not received from the ignition detection circuit 10 after the operation of the timer circuit is completed. A low-power oscillator is configured to ignite the ignition transformer 32 when not receiving a large signal. 134' is a terminal connected to the cathode of the diode 133', which connects the sequence circuit 8 and the ignition detection circuit 10.

135' is a capacitor connected between the diode 134 and the ground terminal 45, 136 and 137 are resistors that connect the positive side of the capacitor 135' and the output terminal of the comparator 127, and 138 and 137 are connected with the pace and emitter. With transistors connected, resistors 136, 137 .
Together with the capacitor 135' and the diodes 133 and 134, it constitutes a timer circuit that operates in conjunction with the ignition operation of the ignition transformer 32. 139Fi) A diode whose cathode is connected to the collector of the transistor 138, 140 is a transistor whose emitter is connected to the anode of the diode 139, 141 is a resistor which connects the emitter of the transistor 146 to the pace, and 142 is connected to the pace of the transistor 140. 143 is a terminal connecting the sequence circuit 8 and the ignition detection circuit 10, 144 is a resistor interposed between the collector of the transistor 140 and the power supply terminal 44, and 145 is a terminal for inputting the collector potential of the transistor 140. An inverter 146 is a relay coil interposed between the relay power terminal 43 and the output terminal of the inverter 145, and controls the relay contact 19 to turn on and off. 147
148 is a terminal that connects the sequence circuit 8 and the vibration detection circuit 9, and 148 is an inverter whose output terminal is connected to the terminal 147. When the ignition detection circuit 10 becomes abnormal when the combustion blower 27 is stopped and it is assumed that ignition has been detected, the relay is activated. Turn off contact 19. , 149 is a diode whose cathode is connected to the input terminal of the inverter 148, 150 is a resistor connected to the relay power terminal 4, and 151 is an anode connected to the resistor 150, and a cathode connected to the input terminal of the inverter 148. A diode, 152 is a capacitor interposed between the cathode of the diode 151 and the ground terminal 45, and 153 is a vibration sensor connected in parallel to the diode 151 and the capacitor 152. When a vibration acceleration of 150 to 200 fat is detected, It turns off.

155 is a resistor that connects the terminal 117 and the anode of the diode 149; 154 is a terminal that connects the Fi vibration detection circuit 9 and the ignition detection circuit 10; 156 is a resistor 157.158
, 159 to the ground terminal 45, which causes a voltage drop when a flame current flows. 160
is a capacitor connected in parallel with resistors 158 and 159,
161 is a capacitor connected in parallel to the resistor 159, 1
A resistor connected to the positive terminal side of the 62-digit capacitor 161, 1
63.167 is a voltage dividing resistor, 164H is an hfC capacitor interposed between the selective resistor 162 and the ground terminal 45, 165
is a constant voltage diode connected in parallel to the capacitor 164, 166 is a capacitor connected in parallel to the resistor 163, and 169 is the positive m (M! Comparators placed on the non-inverting side, 168 is comparator 1
69. 170 is a resistor connected to the power supply terminal 44, 171 is a diode interposed between the output terminal of the comparator 169 and the terminal 134', and 172 is a comparator. A diode 1 interposed between the output terminal of 169 and the resistor 110.
13 is an inverter whose input terminal is connected to the anode of the diode 172; 174 is a terminal connecting the oscillation circuit 11 and the sequence circuit 8; 115 is a pulse transformer; 17
6 is a semi-fixed resistor, 177 is a resistor, 178 is a PUT whose anode is connected to the resistor 177 and the cathode is connected to the pulse transformer 195, 199 is the pulse transformer 175 and the terminal IT
181 is a diode inserted between the pulse transformer 175 and the terminal 134' so that its cathode is connected to the terminal 134'; is the capacitor connected in parallel to the pulse transformer 175, and 182 is the PUT
183 is a capacitor inserted between the anode of PUT 178 and the anode of diode 180, and 184 is connected in parallel to resistor 182. The capacitor 185 is connected to the capacitor 18 along with the diode 186.
A resistor 187 and a semi-fixed resistor 188 are connected between the anode of the diode 186 and the terminal 91, and a semi-fixed resistor 189 is connected between the anode of the diode 186 and the terminal 104. 190 and 191 are terminals connecting the oscillation circuit 11 and the pump drive circuit 12,
192 is a noise absorbing capacitor interposed between terminals 190 and 191, 193 is a resistor connected to terminal 190, 194 is a resistor, and 195 is a transistor to which the potential difference of resistor 194 is applied between the pace emitter. , 196,
197 is a resistor and a capacitor connecting the collector and emitter of the transistor 195, 198 is a semi-fixed resistor, 19
9 is a resistor interposed between the semi-fixed resistor 19B and the resistor 196, 200 is a PUT whose anode and cathode are connected in parallel to the resistor 196 and the capacitor 197, and 201 is a PUT.
A capacitor connecting the gate and cathode of UT200, 202 is a constant voltage diode, 203, 204 is a diode connected in series with the constant voltage diode 202, 20
5, 206, 207 are voltage dividing resistors, resistors 206, 20
7 is a constant voltage diode 202 and diodes 203, 20
4 is connected in parallel with the resistor 207, and the potential difference of the resistor 207 is PUT.
It is connected to the gate of 208. 208 is PUT2
Diode with cathode connected to the gate of 00, 20
9 is a resistor, 210 is a capacitor, 211 capacitor 2
A resistor 212 is connected in parallel to the resistor 10, and a diode 212 is interposed between the resistor 209 and the resistor 211, and its anode is connected to the anode of the diode 208. 219 from malfunctioning. 213 is a resistor 209,2
11 and a capacitor connected in parallel to diode 212, 214 and 215 are diodes and resistors, and 216 is resistor 2.
a transistor whose base and emitter are connected to 15; 2;
19 is a resistor, 219 is a pump connected to the collector of the transistor 216, 218 is a diode for absorbing the surge generated by the pump 219, 220 is a capacitor connected in parallel to the Fi pump 219 and the transistor 216, 221 is a resistor, 222 is a rectifier circuit consisting of a diode bridge that rectifies the alternating current from the terminal 34.

Next, the action will be explained.

When the power switches 17 and 18 are turned on, the DC current is rectified to a predetermined level through the power transformer 35 and the rectifier circuit 37 of the power supply circuit 3 via the terminal 22 and the capacitor 38 .
A stabilized power supply is supplied to the power supply terminal 44 and the relay power supply terminal 43 via the constant voltage diode 41, the transistor 40, etc., and the timer motor 23 is operated. When power is supplied to each power terminal 43, 44, no flame current flows to the main body ground 156, so the output of the comparator 169 becomes H and the transistor 140 is turned on via the terminal 143. However, at the start of operation, the sequence circuit The capacitor 122 of No. 8 is not charged, and even if the output of the comparator 127 becomes H and charging of the capacitor 122 starts, the capacitor 122 will not be discharged while the comparator 127 is outputting H. , the transistor 138 is in an off state, and the input potential of the inverter 145 becomes H, and the output of the inverter 145 becomes L. Therefore, in conjunction with the ON operation of the power switches 17 and 18, the relay coil 146 is excited and the relay contact 19 is turned ON. Furthermore, when power is supplied to the relay power terminal 43 and the power terminal 44, the timer contact 66 is turned on in the heater thermocircuit 4 due to the operation of the timer motor 23, and since the temperature detected by the high temperature thermistor 47 is low, the energy saving switch is switched on. If the comparator 59 is off, the potential Va is equal to or higher than the reference potential Vb set by the resistor 49°50.
2 output is low level (L),! :The relay coil 5T is excited, the tongue relay contact 25 is turned on, and the vaporization heater 24 is activated to generate heat. Due to this heat generation operation, the temperature of the high temperature thermistor 47 rises and reaches the vaporization temperature at time a, and the output of the comparator 52 becomes H. At this time, since the timer contact 66 is in the on state, the non-inverting side of the comparator 88 becomes higher than the inverting side, and the output of the comparator 88 becomes H, so the shifter 103 whose PUTIOI is on
The output becomes H. Therefore, since the inverting side of the converter 114 is higher than the non-inverting side, the output of the comparator 114 becomes L, the 1/- coil 115 is excited, and the combustion blower 27 starts operating with a strong output via the relay contact 26. Further, when the inverter 103 becomes an H output, the capacitor 122 starts to be charged via the resistors 126 and 132 almost at the same time, and the charging potential of the capacitor 122 reaches the resistor 1 at the time point b.
When the voltage exceeds the reference potential set by 20.121, the output of the naruto comparator 127 becomes H, the output of the inverter 129 becomes L, and the capacitor 135' is charged via the resistors 136 and 137. As a result, the relay coil 135 is energized, the relay contact 33 is turned on, and the ignition transformer 32 begins to operate. Also, at almost the same time, the H output of the inverter 103 is transmitted to the PUT 17 via the terminal 104.
Although the anode current of B is set to be lower than the flame current and is input to the oscillation circuit 11 which satisfies the conditions for oscillation, the L output of the inverter 129 also causes the terminal 174 to have an L level potential, and the output of the inverter 86 Since the force is L, the resistance is 187
．． Due to the semi-fixed resistor 188, the gate potential of the PUT 17B becomes relatively low, and the oscillation frequency of the oscillation circuit 11 becomes relatively high. As a result, this relatively high frequency signal is input to the base of the transistor 195 via the pulse transformer 175, and the transistor 195 repeats on/off operations at this frequency. When transistor 195 is on, P
Since the anode potential of UT 200 decreases, PUT 200
is off, and the current flowing through the gate of PUT 200 flows into the base of transistor 216 via diode 214, turning on transistor 216 and pump 219.
is energized and fuel begins to be supplied to the combustion section. And P
After UT 200 turns off, semi-fixed resistor 1 is applied again.
98, the capacitor 199 begins to be charged through the resistors 196 and 199, and after a certain period of time, the PUT 200 is turned on, the transistor 216 is turned off, and the pump 219 is turned on.
Power is cut off.

When the pace signal is input to the transistor 195 again through the pulse transformer 175 in this cut-off state, the transistor 195 is turned on and the PUT 200 is turned off.
Transistor 216 is turned on and power is supplied to pump 219 again. Therefore, the pump 219 is turned on and off at the relatively high frequency of the oscillation circuit 11, and a relatively large amount of fuel is supplied from the pump 219 to the combustion section. Then, at the same time as the ignition transformer 32 operates, the capacitor 122 is discharged via the resistor 126, so the input potential on the non-inverting side of the comparator 127 becomes L, and the comparator 1
The output of 27 becomes L. Therefore, the output of the inverter 129 becomes H, the relay coil 135 is demagnetized, the relay contact 33 is turned off, and the ignition transformer 32 is stopped at point C. On the other hand, the thermistor 47 and the controller 52
The vaporization heater 24, which was once again generating heat through
Since the output of No. 2 becomes H and the relay coil 57 is demagnetized, the relay contact 25 is turned off and stopped.

If the ignition transformer 32 has ignited by this time, the flame current will flow from the frame rod 36 to the main body ground 1.
56, the AC component is bypassed to the capacitor 160, and only the DC component flows to the resistors 158 and 159. Due to the time constant of the capacitor 161 and the resistors 157 and 158, the converter 169 outputs L after a predetermined time delay and outputs to the terminal 134. ', 'i43 becomes L, while terminal 154 becomes H. Therefore, even though the capacitor 122 is discharged by the L output of the inverter 103 and the output of the comparator 127 becomes L, the capacitor 135' is released and the transistor 138 is turned on.
By the time 38 is turned on, the comparator 169 is turned on due to ignition.
The output of the inverter 145 becomes L and the terminal 143 becomes L, so the transistor 140 is turned off.The input potential of the inverter 145 becomes H, the output of the inverter 145 is maintained at L, and the relay contact 19 is kept on. .

Due to this ignition, the fuel continues to be supplied and the room is heated, and the temperature detected by the thermistor 77 becomes resistance 67.68, 69 at time d.
．． When the temperature exceeds the set temperature set by the variable resistor To, the output of the comparator 81 becomes L and the inverter 85
The output becomes H.

As a result, the relay coils 83, 84 are demagnetized, the relay contacts 16, 28 are switched, and the convection blower 14 and the combustion blower 2T are in weak operation. Furthermore, the output of the inverter 85 becomes H and the potential of the terminal 91 rises, so the resistor 189
, 185 is applied to the gate of the PUT 178, and the oscillation circuit 11 oscillates at a relatively low oscillation frequency determined by the resistor 177, semi-fixed resistor 176, and capacitor 183. Therefore, the energization frequency of the differential 12190 is reduced, and the amount of fuel transported by the pump 219 is reduced. For example, when the timer contact 66 is turned off by the timer motor 23 at time e, the output of the controller 65 becomes L and the comparator 81
, 88 are forcibly maintained at the L output, and the temperature control circuit 5 is turned off. As a result of this turning off, the pump 219 stops, combustion stops, and the output of the comparator 169 becomes H. This H
Due to the output, the terminals 134' and 143 reach Ht level, respectively, and the transistor 140 is turned on, but the capacitor 135'
has finished discharging, so the transistor 138 is in the off state.The output of the 4-inverter 145 is in the L state and the relay coil 146 continues to be excited, but at this time both terminals 174 and 134' are in the H state. PUT17B turns off, pump 219 stops, and capacitor 10
Due to the discharge through the resistor 107 of 8, the output of the comparator 114 becomes H with a delay, the relay coil 115 is demagnetized, the relay contact 26 is turned off, and the combustion blower 2T is turned off.
Stop at the point. At this time, since the capacitor 135' has finished discharging when the comparator 127 outputs an L signal, the transistor 138 is in the OFF state and the output of the inverter 145 is Lξ, so that the relay coil 146 is maintained in an excited state. Furthermore, since the quadruple element 134' is in the H state, the capacitor 122 that has finished discharging begins to be charged via the resistor 126. On the other hand, even after the combustion blower 2T has stopped, the vaporization heater 24 repeats the heat generation operation according to the temperature detected by the high temperature thermistor 47, so when the vaporization heater 24 reaches the set temperature after the combustion blower 27 has stopped, The comparator 52 outputs H, and the comparator 88 also outputs H. Therefore, PUTlol turns on and inverter 1
Since the output of 03 becomes H, the comparator 114 outputs L and the relay coil 115 is energized and the relay contact 26
turns on. As a result, the combustion blower 27 is operated weakly again at the second point in time. Then, as the charging of the capacitor 122 progresses and at time h the non-inverting input potential of the comparator 127 becomes higher than the inverting input potential, the comparator 127
becomes an H output, and the inverter 129 becomes an L output. As a result, the relay coil 135 is energized, and the relay contact 33 is turned on and low, and the capacitor 123 is discharged. When the inverting side input potential of the comparator 127 becomes equal to or higher than the non-inverting side input potential at time i due to this discharge, the comparator 127 becomes low.
The output of the shimperter 129 becomes H, the sire relay coil 135 is demagnetized, the relay contact 33 is turned off, and the ignition transformer 32 is stopped. If the fire misfires again at point j, the ignition transformer 32 is activated again at point j in the same manner as described above, and if the ignition is not ignited at this time, the flame current will not flow to the main body ground 156, so the output of the comparator 169 becomes H and the terminal 13
4' and 143 become H, while the output of inverter IT3 becomes L. As a result, the capacitor 122 is charged again, but since the transistor 140 is turned on during this charging period, the capacitor 135' is discharged and the transistor 140 is turned on.
38 is also turned on, the input potential of the inverter 145 becomes L and its output becomes H1. Therefore, the relay coil 146 is demagnetized and the relay contact 19 is turned off, and all the elements except the convection blower 14 are turned on at one point in time. It will be in a stopped state.

Further, if the energy saving switch 59 is turned on, the vaporizing heater 24 is not energized when combustion is stopped, and an energy saving effect is exhibited at this time.

Furthermore, to briefly explain the operation of the heat-up memory circuit 6, if the terminal 60 is L when the terminal 92 is H, then P
If UT 101 is off and terminal 104 is low, the combustion sequence will not proceed. On the other hand, if the terminal 60 becomes H, PUTl
ol is turned on, the terminal 104 becomes H, and the combustion sequence begins (4), and once PUTlol is turned on, it does not turn off until the terminal 92 becomes L. This will memorize that the vaporization heater 24 has reached the vaporization temperature.

To briefly explain the operation of the vibration detection circuit 8, when the vibration sensor 153 detects vibration and turns off, the resistor 150
, the capacitor 152 is charged via the diode 151, and the output of the inverter 148 becomes L, and the relay coil 14
6 is demagnetized and the relay contact 19 is turned off.

To further explain the operation of the temperature control circuit 5 in more detail, when the timer contact 66 is on, when the energy saving switch 59 is turned off, a potential corresponding to the resistance of the high temperature thermistor 47 is input to the inverting side of the comparator 52. Therefore, the comparator 52 outputs H-L in accordance with the cough resistance, and the sire coil 57 is energized and braked.

Thereby, the vaporization heater 24 is controlled to a constant temperature.

On the other hand, if the energy saving switch 59 is turned on, the timer contact 66 turns off and when the special combustion stops, the comparator 8
8 is forcibly maintained at L output, the inversion side input potential of comparator 52 is held at L via energy saving switch 59, comparator 52 becomes H output, relay coil 57 is demagnetized, and vaporization heater 24 is energized when combustion is stopped. The energy saving effect is achieved.

In addition, when combustion is stopped, please refer to the combustion blower 2 for details.
7 is stopped and the output of the comparator 169 becomes L due to an abnormality in the ignition detection circuit 10, the inverter 13
Since the output of 7 is H and the output of the comparator 114 is H, the output is H to the inverter 148 via the diode 149.
The potential is input and the output of the inverter 148 becomes L. As a result, the input of the inverter 145 becomes L and the output of the inverter 145 becomes H, so the relay coil 146 is demagnetized and the relay contact 19 is opened.

Therefore, if the ignition detection circuit 10 is abnormal, the power supply to each element is cut off, resulting in excellent safety.

As explained above, according to this 8AK, the power supply is cut off if the ignition detection circuit becomes abnormal when the combustion blower is stopped (uncombusted), so even if the ignition detection circuit becomes abnormal, ignition is detected. Even if one considers this to be the case, a violent explosion will not occur because the fuel is supplied next to the combustion control circuit, and an extremely safe combustion control circuit can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a combustion control circuit according to an embodiment of the present invention, FIGS. 2 to 8 and 10 to 13 are detailed circuit diagrams of each of the above blocks, and FIG. 9 is a capacitor 12.
2 and the capacitor 135; a shows the voltage characteristic diagram of the capacitor 122. b is a capacitor 135. FIG. 14 shows a timing chart of the combustion control circuit. 5... Temperature control circuit 9... Vibration detection circuit 1o.
...Ignition detection circuit 19...Relay contact 88.
... Comparator 103 ... Inverter 11
4... Comparator 115... Relay coil
148...Inverter 150...Tiode 169...Comparator 173...Inverter agent Makoto Kuzuno (1 person J

Claims (1)

[Claims] In the combustion control circuit, which includes a relay that is excited by the ON operation of the power switch and continues to supply power to each element, a combustion blower and an ignition detection circuit, and the combustion blower is stopped, the ignition detection circuit detects ignition when the combustion blower is stopped. A combustion control circuit characterized by having a means for turning off a front relay when detected.