JPS6238613B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention detects oxygen deficiency and issues an alarm.
This relates to combustion appliances equipped with an oxygen deficiency safety device that stops combustion.

Structure of a conventional example and its problems Figure 1 is a schematic diagram of a conventional kerosene stove, in which heating is performed by reflecting combustion heat burned by a combustion tube 3 using a reflector plate 2 in an exterior 1. Turn the knob 4 to raise the wick inside the combustion tube 3, and press the button 5 to ignite the wick. Note that 22 is a light emitting diode that indicates the operation of the control circuit, and 25 is a switch for stopping combustion. FIG. 2 is a cross-sectional view, in which the ignition heater 9 approaches the lamp wick 6 by pressing the push button 5, and is ignited by the voltage applied from the power source of the dry battery 7. At the same time, the switch 8 is activated and the control circuit 17 starts operating. Inside the combustion tube 3, there are inner and outer flame tubes 12 and 13, and primary combustion air A flows through the central portion thereof. A knob 4 for raising and lowering the wick 6 is attached to the fuel tank 10, and the knob 4 has a coaxial ratchet 19, which is locked by a locking mechanism 24, so that when the wick 6 is raised, The cam 23 operates the micro switch 20 to change the AC power voltage to the code 18.
is applied to the control circuit 17 by. In addition, 26 is the pendulum of the earthquake-resistant automatic fire extinguishing system, and pendulum 2
6 acts to release the lock 24, and the knob 4 returns to its original position, stopping combustion. Note that when the solenoid 11 operates, the pendulum 26 is moved to perform a similar operation. Further, the combustion exhaust gas B rises toward the top plate 21 of the main body, and a case 15 in which an oxygen deficiency sensor 14 is installed is attached to the top plate 21. The signal of the sensor 14 is connected to the lead wire 1 wired on the back of the main body case 1.
6 is connected to the controller. Figure 3 shows the characteristics of the tin oxide-based oxygen deficiency sensor 14, when this sensor 14 is installed in the position shown in Figure 2.When the oxygen concentration is high, carbon monoxide is generated. However, as the oxygen concentration decreases, more carbon monoxide is generated, which reduces the resistance value. FIG. 4 shows a control circuit 17 using this sensor 14. A closed circuit is constructed by connecting a diode 42, a resistor 43a point, a zener diode 44, a point c, and a micro switch 20 from an AC power cord 18 that enters from an outlet. There is. Zener diode 44 connects capacitor 45 in parallel, a-c
A DC power supply is constructed between the points.

Further, the dry battery 7, the switch 8-point b, and the ignition heater 9-point c form a closed loop. From point b, connect diode 27 - resistor 28 - point d - resistor 29 between points c, resistor 30 - point e resistor 31, solenoid 11 - point f - transistor 32 between points a and c.
Connect. Next, the point de is connected to the positive and negative inputs of the operational amplifier 33, and a resistor 41 is connected between the output points g and d. From point g, a circuit consisting of light emitting diode 22, resistive oxygen deficiency sensor 14, point h, and resistor 35 is connected to point c. A resistor 37 is connected to the output point i and h of the operational amplifier 36, which receives positive and negative inputs from points h and e, and a resistor 38 from point i to point j to resistor 39 is connected to point c. The base of the transistor 32 is connected to the point J, and the diode 40 is connected between the collector point F and the point A.

The operation of this circuit is such that by rotating the knob 4, the lamp wick 6 is raised and the micro switch 20 is also activated. Generally, if left in this state, voltage will only be supplied between points a and c and will not proceed any further. Next, the push button 25 is pressed to close the switch 8, and the ignition heater 9 is energized to carry out the ignition operation and the lamp wick 6 is ignited. Oxygen deficiency detection operation is performed from this time. That is, due to the voltage of the dry battery 7, point b becomes higher, point d also becomes higher than point e, and the output point g of the operational amplifier 33 becomes high. At this time, the light emitting diode 22 lights up to notify that the oxygen deficiency detection operation is being performed. If the oxygen concentration in the room is now low, the resistance value of the oxygen deficiency sensor 14 will decrease,
When the potential at point h becomes higher than point e, the operational amplifier 36
The output at point i becomes high, the transistor 32 operates, and current flows through the solenoid 11. As a result, the pendulum 26 is moved, the locking mechanism 24 releases the lamp wick 6, the lamp wick 6 is lowered, the knob 4 is returned to its original position, and combustion is stopped.

In this way, the operational amplifier 33 is self-maintaining because it is powered by the dry battery 7. However, in reality, the voltage of the dry cell battery 7 may run out, and there may be cases where a match ignites. Even in such a case, it is necessary to detect oxygen deficiency, and therefore, a device that uses the dry cell battery 7 as a power source may not be usable.

Purpose of the Invention It is therefore an object of the present invention to enable use with or without a dry battery power source.

Structure of the Invention Therefore, the present invention includes a combustion section, an oxygen deficiency detection sensor provided in a chamber from which exhaust gas from the combustion section is released, and an alarm means or means for stopping combustion based on the output from the oxygen deficiency detection sensor. a control circuit for activating, a battery power source for an ignition heater that ignites the combustion section, an AC power source for the control circuit, and a changeover switch that is selectively connected to the ignition heater and an input section of the control circuit; When the changeover switch is switched to the ignition heater side and the battery power source is connected to the ignition heater, an input signal for starting a control operation is applied to the control circuit.

DESCRIPTION OF THE EMBODIMENT As shown in FIG.
constitutes a closed loop, and the Zener diode 4
Connecting a smoothing electrolytic capacitor 45 in parallel to 4 is the same as in the conventional case. Next, a closed loop is formed between the dry working pond 7, the ignition heater 9, the normally open contact 8'' of the switch 8, the center of the switch 8, and the point c. Also, between points a and c, there is a resistor 28, and the point d. Resistance - normally closed contact 8' of contact 8 - center of switch 8, resistance 30
- Point e - A circuit of resistor 31 is connected, and a capacitor 46 is connected between points d and c. Other details are the same as in Figure 4.

The operation of this circuit is that when switch 20 is closed, aa
- It is the same that a DC voltage is generated between points c. However, ignition is different. That is, when the switch 8 is connected to the normally closed contact 8' and remains switched to the control circuit side, the positive input point d of the operational amplifier 33 is low due to the capacitor 46, and therefore the output point g of the operational amplifier 33 is low. It's summery. Therefore, resistors 29 and 41 are connected in parallel, and resistor 28
, the point d is lower than the point e, and the capacitor 46
Even if there is additional charging, the state remains as it is, the output point g is low, and the light emitting diode 22 does not light up.

At this point, if you press the ignition button 8, the contact will fall towards the normally open contact 8'', so the ignition heater 9 will heat up.
Ignition is carried out, but at the same time the normally closed contact 8' is opened, and in this state, the capacitor 46 is further charged and the resistor 28,
Since 29, 30, 31, and 41 are selected, the g point will be high at that point. At this time, operational amplifier 33
outputs a voltage substantially equivalent to the voltage at point a, which is the power supply voltage of the operational amplifier 33, so the voltage at point d becomes higher than the potential at point e via the resistor 41. Therefore, the operational amplifier 33 self-maintains the output point g at a high voltage, and even if the switch 8 returns to the normally closed contact 8' by releasing the hand, the diode 22 is not turned on until the point g remains high. lights up and the oxygen deficiency detection operation is activated. The subsequent operations are the same as before. In this way, a circuit is provided that can start even if the dry battery 7 power supply is exhausted.

Effects of the Invention As described above, in the present invention, when the switch connected to the control circuit side is switched to the ignition heater side and the battery power source is connected to the ignition heater, an input signal to start the control operation is applied to the control circuit and oxygen deficiency detection starts. It is something.

Therefore, when there is battery power, the control circuit will of course start detecting the ignition from the battery, but even if the battery power runs out and ignition is performed using a match, the control circuit will still be able to control the ignition heater as long as the switch is switched to the ignition heater side. It can be made so that there is no problem in the detection operation of the circuit.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a typical kerosene stove.
FIG. 2 is a sectional view of the kerosene stove, FIG. 3 is a characteristic diagram of the oxygen deficiency sensor, FIG. 4 is a circuit diagram thereof, and FIG. 5 is a circuit diagram of an embodiment of the present invention. 8...Switch, 9...Ignition heater, 11...Solenoid, 14...Oxygen deficiency sensor, 34...Light emitting diode.

Claims (1)

[Claims] 1. A combustion section, an oxygen deficiency detection sensor provided in a room from which exhaust gas from the combustion section is released, and a control circuit that operates an alarm means or a means for stopping combustion based on the output from the oxygen deficiency detection sensor; The control circuit includes a battery power source for the ignition heater that ignites the combustion section, an AC power source for the control circuit, and a changeover switch that is selectively connected to the input section of the ignition heater and the control circuit, and the control circuit connects the changeover switch to the ignition heater side. A combustion appliance configured such that when a switching battery power source is connected to an ignition heater, an input signal for starting a control operation is applied to the control circuit.