JPH05188023A - Control circuit of equipment having gas sensor - Google Patents

Abstract

PURPOSE:To obtain a control circuit of a simple circuit constitution which is not operated until a gas senor becomes stable and is of power-saving type, and securely controls the equipment depending on the filthiness in a room after the gas sensor gets stable. CONSTITUTION:A temperature detecting device 9 is provided within a gas senor 6 or in the vicinity of the gas sensor 6, and a calculating control circuit 12 to start the calculation interlockingly with the output of the temperature detecting device 9 and to realize control according to the output of the gas sensor is provided. A suturation point detecting device to detect the saturation point of the temperature value of the gas sensor is provided, and a calculation control circuit to start the calculation interlockingly with the output of this detecting device and to realize control according to the output of the gas sensor is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device having a gas sensor.

[0002]

2. Description of the Related Art Conventionally, a gas sensor which outputs in a form such as a change in resistance value in response to dirt in a room, has as its constituent elements a resistance whose resistance value changes when gas adheres and a coil which heats the resistance. Is common. When a device is operated in an air purifier or the like, the gas sensor is heated by the coil, and the resistance value increases as the resistance is heated, so that the gas is detected. If the room is clean, the resistance value remains the same, but when smoke or the like reaches the gas sensor, the resistance value decreases due to the gas component contained in the smoke. The change is detected to determine that the room is dirty, and control such as operating the device at high input is performed.

[0003]

However, in this case, the resistance value is not stable during the time from the start of operation of the equipment until the temperature of the resistance reaches a stable state, and it is not possible to accurately determine the dirt in the room. Has a low resistance value and gives an output similar to that when the room is dirty (see FIG. 7). Therefore, until now, until the gas sensor became stable, the equipment was in operation regardless of indoor dirt. The present invention provides a control circuit with a simple circuit configuration, which does not operate the equipment until the gas sensor stabilizes, saves power, and reliably controls the equipment according to the dirt in the room after the gas sensor stabilizes. With the goal.

[0004]

In order to achieve the above object, the first means is to provide a temperature detecting device in or near the gas sensor, and perform calculation in conjunction with the output of this temperature detecting device. Is provided, and an arithmetic control circuit for performing control according to the output of the gas sensor is provided.

Further, as a second means, a saturation point detecting device for detecting the saturation point of the temperature value of the gas sensor is provided, the calculation is started in conjunction with the output of this detecting device, and the control according to the output of the gas sensor is performed. An arithmetic control circuit for performing the above is provided.

[0006]

By the above means, when the gas sensor is started when the device is used, it is detected that the temperature of the gas sensor portion has reached a stable temperature, and then the device is controlled in accordance with the output of the gas sensor which changes according to the dirt in the room. Therefore, the device is not operated until the gas sensor is in a stable state, power saving is realized and the device is controlled after detecting that the gas sensor is reliably stable, so the device is properly controlled, You can make the room comfortable. Further, according to the second means, the stability of the gas sensor is detected without being affected by the ambient temperature, so that the control can be made more appropriate and the comfort in the room can be maintained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In the figure, reference numeral 1 is an air purifier body, which has a fan 2, a drive motor 3 and a filter 4 built therein. Reference numeral 5 is a control circuit for controlling the drive motor 3, and a gas sensor 6 is provided. The gas sensor 6 is generally composed of a resistor 7 whose resistance value changes when gas adheres and a coil 8 for heating the resistor 7. Reference numeral 9 denotes a temperature detecting device installed in the gas sensor, which may be the thermistor 10 or the like. Reference numeral 11 is a variable resistor for setting a reference voltage for the gas sensor output. The calculation control circuit 12 starts calculation in accordance with the output of the detection device 9, and it may be considered to use a comparator. The arithmetic and control circuit 12 compares the output voltage from the gas sensor with the reference voltage, judges the contamination in the room, and controls the input of the drive motor 3. More specifically, when the air cleaner 1 is operated, the gas sensor 6 is heated by the coil 8. The resistance of the resistor 7 increases as it is heated, and the resistor 7 is in a state of detecting gas. If the room is clean, the resistance value remains the same, but when the smoke or the like reaches the gas sensor 6 and the smoke reaches the gas sensor 6, the resistance value decreases due to the gas component contained in the smoke.
According to the present invention, the temperature detecting device detects that the temperature rise of the coil at the start of operation is close to the saturation point, and after receiving the signal, the arithmetic control circuit performs control according to the output of the gas sensor, so that the gas sensor is stable. The motor 3 is not driven, and after the sensor becomes stable, for example, when smoke reaches the gas sensor 6 and the smoke reaches the gas sensor 6, the resistance value decreases due to the gas component. It is determined that the drive motor 3 is dirty, and control such as driving the drive motor 3 with high input is performed. Therefore, until the gas sensor is in a stable state, power saving is realized, and after detecting that the gas sensor is reliably stable, the device is appropriately controlled and the room can be made comfortable.

Next, another embodiment of the present invention is shown in FIG. That is, in the above embodiment, the saturation point detection device 13 for detecting the saturation point where the temperature of the gas sensor has risen is provided. As a result, it is possible to detect that the temperature of the gas sensor has reached a stable state, and it is possible to realize stable control that is not affected by the ambient temperature.

[0009]

According to the present invention, in an air purifier or the like, a temperature detecting device is provided in or near the gas sensor, the calculation is started in conjunction with the output of the temperature detecting device, and the output of the gas sensor is detected. By providing an arithmetic control circuit that performs control according to the above, the equipment will not operate until the gas sensor is in a stable state, which saves power and controls the equipment after detecting that the gas sensor has stabilized reliably. Therefore, the equipment can be properly controlled and the room can be made comfortable. Furthermore, by providing a saturation point detection device that detects the saturation point of the temperature of the gas sensor, by starting an operation in conjunction with the output of this detection device, and by providing an operation control circuit that performs control according to the output of the gas sensor, Since the gas sensor detects that the gas sensor is stable without being affected by the ambient temperature, the control can be made more appropriate, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view of the air purifier.

[Figure 3] Exploded view of the gas sensor

FIG. 4 is a circuit diagram of the air purifier.

FIG. 5 is an operation explanatory diagram of the embodiment.

FIG. 6 is a circuit block diagram showing a second embodiment of the present invention.

FIG. 7 is an operation explanatory diagram of a conventional example.

[Explanation of symbols]

 1 Air Cleaner Main Body 3 Drive Motor 5 Control Circuit 6 Gas Sensor 7 Resistance 8 Coil 9 Temperature Detection Device 12 Arithmetic Control Circuit 13 Saturation Point Detection Device

Claims (2)

[Claims] 1. A temperature detecting device is provided in or near the gas sensor, and an arithmetic control circuit is provided to start arithmetic in conjunction with the output of the temperature detecting device and perform control according to the output of the gas sensor. Control circuit of equipment with gas sensor. 2. An arithmetic control circuit which is provided with a saturation point detection device for detecting the saturation point of the temperature value of the gas sensor, starts arithmetic in conjunction with the output of this detection device, and performs control according to the output of the gas sensor. A control circuit for a device having a gas sensor.