JPS58200924A - Control circuit for combustion - Google Patents

Abstract

PURPOSE:To select either of the improvement of an energy-saving effect and that of a rise performance of combustion as occasion requires, by constituting a device such that either of energization and disconnection of a heater for evaporating fuel can be selected when combustion is brought to a stop by a combustion control. CONSTITUTION:With an energy-saving switch 59 turned OFF when a timer contact 66 is brought to an ON state, a potential coresponding to a resistance of a high-temperature thermistor 47 is inputted to an inversion side of a comparator 52, whereby the comparator 52 has an ''H'' output or an ''L'' output dependent upon the resistance, and a relay coil 57 is energized for control. This causes controlling of a heater 24 for evaporation to maintain it at a constant temperature. Meanwhile, if the energy-saving switch 59 is brought to an ON state, a comparator 88 is forcedly at an ''L'' output when combustion is brought to a stop in the case of the timer contact 66 being turned OFF and the like, an input potential at the inversion side of the comparator 52 is held in the ''L'' through the energy-saving switch 59, the comparator 52 has the ''H'' output, the relay coil 57 is magnetically erased, and the heater 24 for evaporation 24 is prevented from being energized when combustion is brought to a stop.

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, this type of combustion control circuit has a configuration in which when combustion is stopped due to combustion control, a heater for fuel vaporization is maintained at a constant temperature so that an ignition operation is immediately performed when combustion is restarted. For this reason, even when combustion is stopped by combustion control, electricity is supplied to the vaporizing heater, resulting in wasted power consumption.

There are some devices that cut off the power to the vaporization heater when combustion is stopped to eliminate unnecessary operation, but this requires preheating of the vaporization heater when re-igniting, so the ignition time is long. This has the disadvantage of deteriorating performance.

The present invention has been made in view of the above points, and is a combustion control that eliminates the above-mentioned conventional disadvantages by making it possible to select whether to energize or cut off electricity to the vaporization heater when combustion stops due to combustion control. It provides a circuit.

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, and 5 is a temperature control circuit that controls the amount of combustion by controlling combustion operation stop and combustion rice etc. in order to maintain and control the room temperature constant. , 6 is a heat-up memory circuit that stores information that the temperature of the vaporization heater has risen to a temperature that vaporizes the fuel;
1 is a boss purge circuit that delays and stops the combustion blower for a certain period of time when combustion is stopped by the temperature control circuit 5;
8 is a sequence circuit that performs a 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 an ignition detection circuit that detects the combustion state of the combustor; 11 12 is an oscillation circuit that controls the supply 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, and 15#-i is a combustor abnormal heating circuit. 16 is a relay contact that switches the output of the blower according to the excitation state of a relay coil 83 (described later); 17 and 18t'i are both power switches; i! #The switch 17 maintains its state when it is turned on.The partial power switch 18 closes only the moment it is turned on. .

19F'i is a relay contact that turns on and off in accordance with the excitation of the relay coil 146 described above, and is connected in parallel to the power switch 18. , 20i1/is absorption capacitor, 2
1 is a surge absorber, 22 is a terminal for connecting the power supply circuit 3 and the relay circuit 2, 23 is a timer motor for automatic operation, 24 is a heater for vaporizing liquid fuel, and 25 is connected in series to the heater 24. This is a relay contact that controls energization of the heater 240, and takes an on/off state depending on the excitation state of a relay coil 5T, 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#i is an output of the blower 2T, which switches according to the excitation state of a relay coil 84, which will be described later. Relay contact for switching, 29.31
Hj, a resistor and a capacitor for surge absorption; 31, a surge absorber; 32, an ignition transformer; 33Fi, a relay contact that turns on and off according to the excitation of a relay coil 135, which will be described later, to control the ignition transformer 32; and 34, a relay circuit 2; 4! 35 is a power transformer, 36 is a flame rod for detecting flame current (
(not shown), 31 is a rectifier circuit consisting of a diode bridge, 38 is a smoothing capacitor, 39
is a resistor, 40 is a transistor, 41 is a constant voltage diode, 42 is a Fi capacitor, resistor 39, transistor 40
A stabilized power source is supplied together with the constant voltage diode 41. 43 is a relay power supply terminal for excitation of each relay coil;
4 is a stabilized power supply terminal for other circuits, 45 is a ground terminal, 46 is a resistor, 47tj is a high temperature thermistor that is attached to the vaporization heater 24 and detects the temperature of the vaporization heater 24;
8 is a capacitor connected in parallel to the thermistor 47;
9. 50 is a voltage dividing resistor, 51 is a capacitor connected in parallel to the resistor 50, 52 is a potential va between the resistor 46 and thermistor 47, and a potential yb between the resistors 50 and 51, which is inverted. Comparators to which the inverted side is input, 53, 54
A resistor and a diode are interposed between the output of the i1 comparator 52 and the non-inverting input terminal, 55 and 56 are diodes whose anodes are connected between the resistor 46 and thermistor 47, and 5γ is a relay contact. 25 is a relay coil that controls ON/OFF of the relay coil 25 and is excited according to the output of the comparator 52. 58 is a diode for canceling back electromotive force, and 59 is an energy-saving system that selects whether or not to energize the vaporizing heater 24 when combustion is stopped by the temperature control circuit 5 connected in series with the diode 56, that is, when the comparator 88 outputs an output. Nochi, 6
0 is a terminal that connects the heat-up memory circuit 6 and the heater thermocircuit 4, 61.62 is a terminal that connects the heater thermocircuit 4 and the temperature control circuit 5, 63 is a resistor, and 64 is a terminal 6
1 is a diode with its cathode connected; 65 is an inverter consisting of a transistor array IC formed by incorporating several transistors into the same IC; 66 is a timer contact controlled on and off by the timer motor 23;
8. 69 is a voltage dividing resistor connected in series between the power supply terminal 44 and the ground terminal 45, 10 is a variable resistor connected in parallel to the resistor 69, 11 is a capacitor, ? 2,7
4, 75, and 76 are resistors connected in series between the power supply terminal 44 and the ground terminal 45, and 73 is a diode 6.
TI is a thermistor for room temperature detection connected in parallel to resistor 76, T8 is a resistor, 79 is a capacitor, and 81 is a capacitor T1. A comparator into which the positive potential of the capacitor 78 is input to the inverting side and the potential of the positive electrode of the capacitor 78 to the non-inverting side; 80 is a resistor connecting the output terminal of the comparator 81 and the non-inverting input terminal; 82 is the comparator 81; 83 is a relay coil that switches and controls the relay contact 16, 84 is a relay coil that switches and controls the relay contact 28, 85#i The output terminal of the comparator 81 and the relay coil 83゜84 The inverter inserted between 86F and 85
87 is a capacitor interposed between the resistor 13 and the ground terminal 45, and 88 is a diode whose cathode is connected to the output terminal of the capacitor 71. Comparators each input to the inverting side, 89 a resistor connecting the output terminal of the comparator 88 and the non-inverting side input terminal, 90 a power supply terminal 4
A resistor connecting 4 and the output terminal of the comparator 88, 9
1 is a terminal for connecting the temperature control circuit 5 and the oscillation circuit 11; 92;
93 is a diode whose cathode is connected to the terminal 60, 94 is a resistor connected to the anode of the diode 93, and 95 is a terminal whose cathode is connected to the terminal 92. diode,
96 is a resistor connected to the anode of the diode 95;
1 is a capacitor interposed between the resistor 96 and the ground terminal 45, a resistor 99 connects the 98tl power supply terminal 44 and the resistor 94, a resistor 99 connects the 100ti resistor 9s and the connection point between the resistor 98 and the resistor 96. A capacitor 101 is a PUT whose anode is connected to the connection point of resistors 96 and 98 and a gate is connected to a resistor 99. 102 is a PUT 101
12) A diode whose anode is connected to crab/-) and whose cathode is connected to the ground terminal 45, 103 is P
An inverter is connected to the gate of UTlol, 104 is a terminal that is connected to the heat array memory circuit 6 and sequence circuit 8 -, 105 is a resistor that connects the power supply terminal 44 and the terminal 104, and 106 is an anode connected to the terminal 104. 107 is a resistor connected in parallel to the diode 106, 108 is a capacitor interposed between the resistor 107 and the ground terminal 45, and 109 is a capacitor interposed between the cathode of the diode 106 and the power supply terminal 44. resistor 105.107. Daioh)'10
6 and the capacitor 108 constitute a CR511 circuit. 110, 111i1 are voltage dividing resistors, 113#'i
.

A capacitor 114 is connected in parallel with the resistor 110, a comparator 114 is connected, a resistor 112 is a resistor that connects the output terminal of the comparator 114 and the non-inverting input terminal, and a relay fill 115 is a relay fill that controls on/off the relay contact 26, which is connected to the relay power terminal 43. 116 is a diode for canceling the back electromotive force of the relay coil 115, and 117e is a post purge circuit I.
119 is a resistor connected to the terminal 104, 120°1
21#'i A voltage dividing resistor connected in series between the power supply terminal 44 and the ground terminal 45, 122 a capacitor, 123 a capacitor connected in parallel to the resistor 121, 124ti capacitor 123 125 is a diode interposed between the capacitor 122 and the resistor 119, and 126 is the diode 12.
5 is the resistor connected to the anode, 127 is the capacitor 1
A comparator 12 to which the positive potential of the capacitor 123 is input to the non-inverting side and the positive potential of the capacitor 123 to the inverting side.
8t'i comparator 127 output terminal and power supply terminal 44
129 is an inverter whose input is the output of the comparator 122, 130tf:.

A diode is interposed between the resistor 124 and the output terminal of the inverter 129, 131 is a diode whose cathode is connected to the output terminal of the inverter 129, and 132 is a connection between the power supply terminal 44, 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 is a diode whose cathode is connected to the anode of the diode 133. 135 is a relay coil that controls the relay contact 33 on and off. It is connected between the power supply terminal 43 and the output terminal of the inverter 129.

133' is a diode whose anode is connected to the resistor 132, and the resistors 119, 120, 121.124°126.
128, 132, capacitors 122, 123, diodes 125, 130, 131, comparator 127, and inverter 129, which are the main parts of the present invention - When the ignition signal is not received from the ignition detection circuit 10 during the operation of the timer circuit described later, the relay While the contact 19 is turned off, a low frequency oscillator is configured to operate the ignition transformer 32 to ignite when no ignition signal is received from the ignition detection circuit 10 when the timer circuit ends its operation. , 134 are terminals connected to the cathode of the diode 132, which connect the sequence circuit 8 and the ignition detection circuit 10. ■35' is a capacitor connected between the diode 134 and the ground terminal 45, 136,
137 is the positive terminal side of the capacitor 135' and the comparator 1
27 is a resistor connected to the output terminal, 138 is a resistor 137
With nine transistors connected with the pace and emitter, resistors 136.137. Capacitor 135', diode 1
33 and 134 constitute a timer circuit that operates in conjunction with the ignition operation of the ignition transformer 320.

139 is a diode whose cathode is connected to the collector of the transistor 138; 14 is a transistor whose emitter is connected to the 7 node of the diode 139; 141 is a resistor that connects the emitter and base of the transistor 140; 142 is a transistor 1400 connected to the base; Connected resistor, 143 M-connector, 14411) which connects the read-out circuit 8 and the ignition detection circuit 10, a resistor interposed between the collector of the transistor 14G and the power supply terminal 44, 145 Ti, which controls the collector potential of the transistor 140. An input inverter 146 is a relay coil installed 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 is a terminal connecting the Nokens circuit 8 and the vibration detection circuit 9; 148 is an inverter whose output terminal is connected to the terminal 147; 149 is a diode whose cathode is connected to the input terminal of the inverter 14B; A resistor 151 is connected to the terminal 43, a diode 151 has an anode connected to the resistor 154 and a cathode connected to the input terminal of the inverter 148, and 152 a diode 15.
10, a capacitor interposed between the cathode and the ground terminal 45, 153t-j, and a capacitor M and S connected in parallel to the diode 151 and the capacitor 152.
It turns off when a vibration acceleration of 0- is detected.

155 is a resistor that connects the terminal 117 and the anode of the diode 149; 154 is a terminal that connects the vibration detection circuit 9 and the ignition detection circuit 10; 156 is a resistor 157, 158,
The body arc connected to ground terminal 45 via 159 produces a voltage drop when current flows through the flame. 160 is a capacitor connected in parallel with resistors 158 and 159, 1
61 is a capacitor connected in parallel to the resistor 159, 16
1 is a capacitor connected in parallel to a resistor 159, 162
is a resistor connected to the positive side of the capacitor 161, 163
, 167 is a voltage dividing resistor, 164 is a secondary capacitor interposed between the resistor 162 and the ground terminal 45, 165 is a constant voltage diode connected in parallel to the capacitor 164, 1
66 is a capacitor connected in parallel to the resistor 163, 1s
A comparator into which the positive potential of the sFi capacitor 164 is input to the inverting side and the positive potential of the capacitor 166 is input to the non-inverting side, a resistor connecting the output terminal of the 16811t comparator 169 and the non-inverting input terminal, 170 is a power supply Resistor connected to terminal 44, 171 is comparator 1
172 is a diode inserted between the output terminal of comparator 169 and resistor 110, 173 is input to the anode of diode 172. An inverter with terminals connected thereto, 174 a terminal connecting the oscillation circuit 11 and the sequence circuit 8, 175F'i pulse transformer, 176?
'i 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 175, 179 is the pulse transformer 175 and the terminal 11
180 is a diode inserted between the pulse transformer 175 and the terminal 134' so that its cathode is connected to the terminal 134'; is a capacitor connected in parallel to pulse transformer 175, 182#1PU
A resistor is interposed between the gate of f'17B and the anode of the diode 180, 183 is a capacitor interposed between the anode of PUT17B and the anode of the diode 180, and 184 is connected in parallel to the resistor 182. capacitor 185 is connected to capacitor 1 along with diode 186.
184 is a resistor connected in parallel in a trap, 18T and 18B are the resistors and semi-fixed resistors interposed between the anode of the diode 186 and the terminal 91, and 189 is the resistor interposed between the anode of the diode 186 and the terminal 104. 190 and 191 are the terminals connecting the oscillation circuit 11 and the pump drive circuit 12, and 192 is the terminal 1.
193 is a resistor connected to the terminal 190, 194 is a resistor, 195 is a transistor to which the potential difference of the resistor 194 is applied between the base and emitter, 196. 1911m A resistor and a capacitor connecting the collector and emitter of the transistor 195, 198 a semi-fixed resistor, 199 a resistor interposed between the semi-fixed resistor 198 and the resistor 196, 200
connects the anode and cathode to resistor 196 and capacitor 197
201 is a capacitor connecting the gate and cathode of PUT 200, 202 is a constant voltage diode, and 203.204 is a constant voltage diode 2.
Diodes connected in series to 03, 205, 206.
207 is a voltage dividing resistor, resistors 206 and 207 are connected in parallel to the constant voltage diode 202 and diodes 203 and 204, and the potential difference of the resistor 207 is connected to the gate of the PUT 200. 208 is a diode whose cathode is connected to the gate of PUT200, 209#'i resistor,
210 is a capacitor, 211 is a resistor connected in parallel to the capacitor 210, 212Fi resistor 209 and resistor 211
A diode is interposed between rC and the anode of the diode is connected to the anode of the diode 208.
19 to prevent malfunctions. 213Fi resistor 209.21
1 and a capacitor connected in parallel to the diode 212, 214 and 215 a resistor with a diode connected in parallel to the diode 212 and the resistor 211, and 216 a resistor 215.
A transistor with its base and emitter connected to, 217
219 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 bong 219 and the transistor 216, and 221 A resistor 222 is a rectifier circuit consisting of a diode bridge that rectifies the alternating current i from the terminal 34.

Next, the effect will be explained.

When the power switches 17 and 18 are turned on, the current is rectified to a predetermined level through the power transformer 35 of the power supply circuit 3 and the rectifier circuit 37 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 and 44, no flame current flows to the main body ground 156, so the output of the comparator 169 becomes H.
is turned on, but at the start of operation, sequence (b) path 8
The capacitor 122 is not charged, and even if the output of the comparator 121 becomes H and charging of the capacitor 122 is started, the capacitor 122 will not be discharged while the comparator 121 is at HtB power.
The transistor 13B is turned off and the medium inverter 1 is turned off.
450 input potential becomes H and the output of inverter 145 becomes L.
becomes. Therefore, in conjunction with the ON operation of the power switch 17 and the I BID, the relay coil 146 is excited and the relay contact 1S is turned on. In addition, 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 9-child circuit 4 due to the operation of the timer motor 23, and furthermore, the Yokota of the thermistor 4T for still temperature is turned on. Since the knitting is low, if the energy saving switch 59 is off, the potential va will be the base l# set by the resistor 49.50; potential v
b or more, the output of the shift valve 52 is low level (L)
As a result, the relay coil 5T is excited, the 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 thermistor 47 for cylindrical knitting rises, and when it reaches vaporization at point a, the output of the comparator 52 becomes 1 (at this time, since the timer contact 66 is in the ON state, the output of the comparator 88 is Since the inverted side becomes higher than the inverted side and the output of the comparator 88 becomes H, the output of the inverter 103 with PUTIOI on becomes H. Therefore, the inverted @ of the comparator 114 becomes higher than the non-inverted side, so the output of the comparator 114 becomes H. becomes L, the relay coil 115 is energized, and the combustion air blower A27 starts to operate at a strong output via the relay contact 26.Also, when the inverter 103 becomes H output, it starts to be turned on almost at the same time, and the capacitor 1220 stops charging at point b. When the voltage exceeds the reference potential set by the resistors 120 and 111V, the output of the comparator 127 goes high.
When the output of the inverter 129 becomes L, the VC resistors 136 and 137' are valved and the capacitor is connected! Charged to 35'. ) The relay coil 135 is excited by L, the relay contact 33 is turned on, and the ignition transformer 32 begins to operate.1, 1'fc At the same time, the inverter 103■
The H output is manually inputted via the terminal 104 to the oscillation circuit 11 which sets the anode current of P[JT below the flame current and satisfies the conditions for oscillation uJ 71. Of course, the L of inverter 129
As a result of the output, the terminal 114 also has an L level potential and fL, and since the inverter 85 outputs the resistor 187 and the semi-fixed resistor 188V (:), the PUT 17B (iD gate potential is relatively low and the oscillation frequency of the oscillation circuit 11 is relatively low). 1, C1L? This relatively high frequency signal valves the pulse transformer 175 and is input to the base & C of the transistor 1950, and the transistor 195 repeats on/off operations at this frequency. When the transistor 195 is in the on state, the signal of PUT20G Since the anode potential decreases, PUT
200 is off, and the current flowing to the gate of PUT2tlO flows through the diode 214 to the transistor 21.
Fuel flows into the base of No. 6 and No. 9 also turns on transistor 211j, which energizes the pump 219, and fuel begins to be supplied to the combustion section. Then, after the PUT 200 is turned off, the capacitor 19F starts to be charged again via the semi-fixed resistor 198 and the resistors 196 and 199, and after a certain period of time K P U 1
'2''00 is turned on, the transistor 216 is turned off, and power to the pump 219 is cut off. In this connected state, when a signal is again input to the base of the transistor 1950 via the pulse transformer 175, the transistor 1
Since the transistor 95 is turned on and the PUT 200 is turned off, the transistor 216 is turned on and the pump 219 is energized 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 is activated, 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 output of the hum comparator 127 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. -The vaporization heater 24, which was once again generating heat via the rope knitting thermistor 47 and converter 52, becomes L at the inverting side input potential of the comparator 52 at point C due to the L output of the inverter 65. Then, the w force of the comparator 52 becomes H, and the relay coil 5T is demagnetized, so the relay contact 25 is turned off and stopped.

At this time, if the ignition is ignited in the housing by the operation of the ignition transformer 32, the moxibustion will flow from the flame iron 36 to the main body γ-s 1.
The AC component is bypassed to the capacitor 160, and only the DC component flows to the resistor 158.159. Due to the time constant of the capacitor 161 and the resistor 157.158, the comparator 169 outputs L after a predetermined time delay.

143 becomes L, and one terminal 154#iH becomes.

Therefore, the L output of the inverter 103 causes the capacitor 1 to
22 is discharged and the output of the comparator 127 becomes L, which causes the transistor pump 135' to discharge and the transistor 1
38 is turned on, the output of the comparator 169 becomes L due to ignition before this transistor 138 turns on.
As a result, the terminal 143 becomes L, so the transistor 140
is turned off, the input potential of the inverter 1450 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 T7 becomes 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.
The output of becomes H, which causes the relay coil 83.84
is demagnetized, the Schiller contacts 16 and 28 are switched, and the convection blower 14 and the combustion blower 27 are in weak operation. - Also, since the output of the inverter 85 becomes H and the potential of the multi-terminal 91 rises, the potential determined by the resistors 189 and 185 becomes PU
Applied to the gate of T178, the oscillation circuit 1iFi resistor 177
It oscillates at a relatively low oscillation frequency determined by a semi-fixed resistor 176 and a capacitor 183. Therefore, the pump 21
The energizing frequency of pump 219 is reduced, and the amount of fuel transported by pump 219 is reduced.

For example, when the timer contact 66 is turned off by the timer motor 23 at time 0, the output of the inverter 65 becomes L, the comparator 81.8B is forcibly maintained at the L output, and the temperature control circuit 5 is turned off.

By turning off, the pump 219 stops, combustion stops, and the output of the comparator 169 becomes H. Due to this Httj force, the terminals 134' and 143 each become H potential, turning off the transistor 140, but since the capacitor 135' has finished discharging and the transistor 138 is in the off state, the output of the inverter 145 is in the L state. , and relay coil 146 continues to be energized, but at this time terminal 174
, l 34' both become H, so PUT 17B turns off, pump 219 stops, and capacitor 10
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 27 is turned off.
Stop at the point. At this time, the capacitor 135'# has finished discharging at the L output of the capacitor 127, so the transistor 138t! Inverter 145 is in off state
As a result, the relay coil 146 maintains the excited state. Also, since the terminal 134' becomes 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 27 stops, the vaporization heater 24 repeats the heat generation operation according to the temperature detected by the high temperature thermistor 4T.
When the vaporization heater 24 reaches the set temperature after T stops, the comparator 52 outputs ■, and the comparator 88 also becomes H.
This becomes the output. Therefore, PUTlol is turned on and the output of the inverter 103 becomes H, so the comparator 114 becomes an L output, the relay coil 115 is excited, and the relay contact 26 is turned on. As a result, at time g, the combustion blower 2
γ is again run weakly. And the capacitor 122
As the charging progresses and the non-inverting side input potential of the comparator 12F becomes equal to or higher than the inverting side input potential at time h, the comparator 12
7 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 the ignition transformer 32 is activated.

When ignition is detected by the ignition detection circuit 10, the terminal 134' becomes L and the sicon pump 122 discharges, and when the inverting side input potential of the sicomarator 127 becomes equal to or higher than the non-inverting side input potential at time C due to this discharge, the comparator 127 127 becomes an L output, 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. If it misfires again at point 3,
Again, in the same manner as above, if the ignition transformer 32 is activated at time h and the ignition is not ignited at this time, no flame current will flow to the main body ground 156, so the comparator 169 (iD output will become H and the terminals 134' and 143 will become H, while the inverter 1
The output of 73 becomes L. This causes capacitor 122 to be charged again, but during this charging period transistor 14
0 is turned on, and as the capacitor 135' is discharged, the transistor 138 is also turned on, so that the inverter 1450
The input potential becomes L and its output becomes H. Therefore, the relay coil 146 is demagnetized, the relay contact 19 is turned off, and all the elements other than the convection blower 14 are stopped at time I.

Further, when the energy saving switch 59 is turned on, the vaporizing heater 24 is not energized when combustion is stopped, and the 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 at the high level when the terminal 92 is at the high level, the output level becomes P.
When the UT101Fi is off, the terminal 104 becomes L and the combustion sequence does not proceed. On the other hand, if the terminal 60 becomes H, PUTI
OI is turned on, terminal 104 becomes H, and the combustion sequence begins, and once PUTIOI is turned on, it does not turn off until 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 9, 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 is L.
6 is demagnetized and the relay contact 19 is turned off.

Further, to explain the operation of the temperature control circuit 5 in more detail, when the timer contact 66 is on, the energy saving switch 59 is turned off.
If r, a potential corresponding to the resistance of the high-temperature thermistor 4T is input to the inverting side of the comparator 52, so that the comparator 52 has a HLm force and the energization of the sire coil 5T is controlled according to the resistance.

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 the L output, and the input potential of the comparator 52 is inverted via the energy saving switch 59, and the input potential is held at L, the comparator 52 becomes the H output, the relay coil 57 is demagnetized, and the vaporization heater 24 is energized when combustion is stopped. The energy saving effect is achieved.

In addition, when the combustion is stopped, even if the output of the comparator 169 becomes L due to an abnormality in the ignition detection circuit 10, the inverter 1
Since the output of the inverter 73 is H and the output of the comparator 114 is H, the H potential is input to the inverter 148 via the diode 149, 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 the present invention, when combustion stops due to combustion control, it is possible to select whether to energize or cut off the power to the six fuel vaporizing heaters, so it is possible to select whether to save energy or improve combustion start-up performance depending on the situation. A practical combustion control circuit can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a continuation 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. capacitor 1
22 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. 4... Heater thermo circuit, 5... Temperature control circuit, 2
3... timer motor, 24... vaporization heater,
25...Relay contact, 47...High temperature thermistor, 52...Comparator, 57...Relay coil, 59...Energy saving switch, 66...Tie? W point, 77... Ser4 star, 88... Comparator. Agent Shin Kuzuno - (1 person) Figure 9 River = 10 - Figure 11 13t: 143

Claims (1)

[Claims] A combustion control circuit including a heater for fuel vaporization, a thermistor that detects the temperature of the heater via a resistance value, and a heater thermocircuit that controls energization of the heater according to the resistance value of the thermistor. When the combustion is stopped by control, the voltage across the thermistor is selectively maintained at a constant voltage regardless of the temperature of the heater, so that the heater length-7 circuit forcibly cuts off current to the heater. A combustion control circuit characterized in that a means is provided.