JPWO2012105520A1 - Battery-powered alarm - Google Patents

Abstract

As the power supply route to the heater resistor 2b of the gas sensor 2, there are two routes: a route for supplying power from the booster circuit unit 12 via the switch SW1 and a route for supplying power from the battery unit 1 via the switch SW4. is doing. While the voltage of the battery unit 1 is normal, the control circuit unit 11 controls the switch SW4 to be ON so that the battery voltage of the battery unit 1 is applied to the heater resistor 2b. When the value is less than the threshold value, the switch SW1 is controlled to be ON, and the boosted voltage of the booster circuit unit 12 is applied to the heater resistor 2b.

Description

  The present invention relates to an alarm device such as a fire alarm device or a gas leak alarm device, and more particularly to a battery-type alarm device.

  Conventionally, as described in, for example, Patent Document 1, for example, in a fire alarm, a battery type is naturally used when a battery is used for a long period of time. That is, at the end of the use period, the voltage of the battery as the power source decreases, and if left as it is, the function is finally stopped. Therefore, the fire alarm for homes constantly monitors the voltage drop of the battery as a power source, and when the battery voltage approaches the voltage value at which the function stops, the battery is replaced (or the time for replacing the entire alarm has arrived). A function to notify is added.

  The invention of Patent Document 1 proposes a reference value setting method for battery voltage drop that enables accurate and inexpensive monitoring of the voltage drop even at delicate battery voltage values at the end of the usage period.

  Further, the battery type alarm device is not limited to the fire alarm device, but includes, for example, a gas leak alarm device. There are many types of gas leak alarms that use a commercial power supply (AC100V) obtained through an outlet (naturally converted to DC5V, for example, and operated with a DC power supply). Battery type has also been developed.

  FIG. 8 is a circuit diagram of a conventional battery-type gas leak alarm.

  The gas leak alarm in the illustrated example includes a battery unit 1, a gas sensor 2, a control circuit unit 3, an alarm unit 4, an ambient temperature detection unit 5, a constant voltage circuit unit 6, a constant voltage circuit unit 7, and three switches SW1 and SW2. , SW3, and a load resistance R1. SW1, SW2, and SW3 are semiconductor switching elements such as bipolar transistors, and are ON / OFF controlled by the control circuit unit 3. The gas sensor 2 includes a sensor resistor 2a and a heater resistor 2b.

  In the following description, the constant voltage circuit unit 6 will be referred to as the first constant voltage circuit unit 6 and the constant voltage circuit unit 7 will be referred to as the second constant voltage circuit unit 7 and will be described in an easily distinguishable manner. To do.

  First, gas detection using the gas sensor 2 (comprising a sensor resistor 2a and a heater resistor 2b) will be described.

  As an example, the sensor resistance 2a has a high resistance such as 100 kΩ, and the heater resistance 2b has a low resistance of about 100Ω. By driving the heater resistor 2b, the heater resistor 2b is heated to the operating temperature (about 400 ° C.) of the sensor resistor 2a which is a gas detection element. Therefore, a large current flows through the heater resistor 2b, and the power consumption is large.

  The control circuit unit 3 can determine the presence or absence of gas by measuring the resistance value of the sensor resistor 2a that is heated to the operating temperature as described above. This measurement / determination method is generally well known and will not be described here. In addition, since the time taken to heat to the operating temperature is affected by the ambient temperature, processing such as determining the drive time of the heater resistor 2b based on the ambient temperature detected by the ambient temperature detector 5 is also possible. It may be done.

  As for the sensor resistance 2a, a series circuit including the sensor resistance 2a, the load resistance R1, and the switch SW3 is formed. As for the heater resistor 2b, a series circuit including a switch SW1, a first constant voltage circuit unit 6, a heater resistor 2b, and a switch SW2 is formed. These two series circuits are connected in parallel, and a predetermined voltage (for example, 3.3 V) is applied by the second constant voltage circuit unit 7 (for example, a booster circuit). Further, a predetermined voltage (for example, 2.0 V) by the first constant voltage circuit unit 6 (step-down circuit) is applied to the heater resistor 2b.

  Here, the control circuit unit 3 is a microcomputer or the like, and controls the gas leak alarm device by executing a predetermined application program stored in advance in its built-in memory. As part of this control, a process of measuring the sensor value of the gas sensor 2 at a constant cycle is performed.

  For example, power is supplied to the gas sensor 2 for about 100 ms with a period of 60 seconds. This controls ON of all three switches SW1, SW2, SW3 every 60 seconds for 100 ms (ON signals are output from the output terminals OUT1, OUT2, OUT3 shown in the figure). Thus, the 3.3V voltage by the second constant voltage circuit unit 7 is applied to the sensor resistor 2a, and the 2.0V by the first constant voltage circuit unit 6 is applied to the heater resistor 2b. A voltage is applied, and thereby the gas sensor 2 is operated.

  The control circuit unit 3 inputs a voltage value indicating a change in the resistance value of the sensor resistor 2a from the illustrated input terminal AD2, and performs a predetermined gas leak determination process based on the voltage value. If it is determined that there is a gas leak, the alarm unit 4 is controlled to issue an alarm / notification.

  The alarm unit 4 includes an alarm sound output unit 4a such as a buzzer, an alarm display unit 4b such as an LED, and an external alarm output unit 4c that is an interface for outputting signals to the outside. The control circuit unit 3 controls these to notify the occurrence of gas leakage by, for example, sounding a buzzer sound or lighting / flashing the LED.

  Here, the battery part 1 is a main power supply of this gas leak alarm, and is a power supply of the voltage of 3.0V in this example. This power supply voltage (3.0 V) is boosted (may be stepped down) by the second constant voltage circuit unit 7 and supplied to the control circuit unit 3, the gas sensor 2, and the like. Here, it is assumed that the voltage is boosted to 3.3V.

  The first constant voltage circuit unit 6 is a step-down circuit that steps down the output voltage of the second constant voltage circuit unit 7 (here, 3.3 V as described above) to 2.0 V, for example. The voltage (2.0 V) is the driving voltage for the heater resistor 2b. That is, with respect to the driving of the heater resistor 2b, the voltage is boosted by the second constant voltage circuit unit 7 and then lowered by the first constant voltage circuit unit 6 (3.0V → 3.3V → 2.0V). The first constant voltage circuit unit 6 and the second constant voltage circuit unit 7 have a double loss, which is very inefficient and uses a large amount of battery current.

  The heater resistor 2b is a component with very large power consumption. Compared to the heater resistor 2b, the power consumption of the control circuit unit 3 and the sensor resistor 2a is insignificant.

  The first constant voltage circuit unit 6 is a DC-DC converter such as a step-down chopper, for example. The second constant voltage circuit unit 7 is also a DC-DC converter such as a step-up chopper or a step-down chopper, for example.

  Although not shown in the figure, there is a conventional example in which the second constant voltage circuit unit 7 does not exist. In this case, if the battery voltage decreases at the end of the battery use described above, normal operation cannot be performed due to the problem of the driving voltage of the heater resistor 2b.

  That is, in this example, the power supply voltage (the voltage of the battery unit 1 of 3.0V) is supplied to the gas sensor 2 and the control circuit unit 3, and the first constant voltage circuit unit 6 supplies the power supply voltage (3V). The voltage is stepped down to 2.0V. When the voltage of the battery unit 1 drops at the end of battery use, the output voltage of the first constant voltage circuit unit 6 also drops, and the drive voltage of the heater resistor 2b decreases.

  As described above, when the driving voltage of the heater resistor 2b is reduced as the battery voltage is lowered, it becomes impossible to heat to the operating temperature. For this reason, it becomes impossible to “measure the resistance value of the sensor resistor 2a in a state where it is heated up to the operating temperature”, so that normal measurement cannot be performed, and therefore, normal gas leak determination cannot be performed. That is, normal operation cannot be performed.

  On the other hand, when the second constant voltage circuit unit 7 (boost chopper) is provided as in the conventional example shown in FIG. 8, the battery is used at the end of battery use as compared with the configuration without the boost chopper as described above. Even if the voltage drops, normal operation is possible for a relatively long time.

However, as already described, in the normal time, the step-up chopper and the step-down chopper cause a double loss, and a large amount of battery current is used, so that there is a high possibility that the lifetime will eventually be shortened.
JP 2008-123347 A

  Here, the gas leak alarm is normally used for 5 years without maintenance. Therefore, even a battery-type gas leak alarm must be usable for 5 years without battery replacement.

  If a large number of batteries are installed, the usage period of 5 years will be fully satisfied. However, from the viewpoint of product cost, product outline, product weight, etc., it is desired from the market to reduce the number of batteries installed. Therefore, it is necessary to reduce the power consumption of the device and satisfy the service period of 5 years with a small number of batteries.

  In order to satisfy the market demands as described above, it is desirable to operate normally as long as possible even at the end of battery use. Eventually, it is highly likely that the lifetime of the alarm will not be prolonged.

  In addition, the said patent document 1 does not consider such a request at all.

  In the above conventional configuration, for example, when the first constant voltage circuit unit 6 is a step-down chopper or the like, and the control circuit unit 3 performs so-called “chopper control” by a control signal from the output terminal OUT3, the battery It is possible to maintain the driving voltage of the heater resistor 2b at a predetermined value (2.0V) by changing the duty ratio of the “chopper control” according to the voltage drop of the section 1, but there is a limit to this. is there. For example, when the voltage of the battery unit 1 is less than 2.2V, the output of the first constant voltage circuit unit 6 is less than 2.0V, and normal operation cannot be performed.

  An object of the present invention relates to a battery-type alarm device, and in particular, with respect to a configuration relating to sensor driving, loss of battery consumption can be reduced, and the time during which normal operation can be performed at the end of battery use can be extended. Therefore, it is to provide a battery type alarm device that can realize a long life of the alarm device.

  The battery-type alarm device of the present invention has the following configuration on the premise that the battery-type alarm device has at least a sensor part and a battery.

  First, a booster circuit unit that boosts the battery voltage is provided.

  Furthermore, it has the 1st electric power supply path for giving the said battery voltage to the said sensor part, and the 1st switch means provided on this 1st electric power supply path.

  Furthermore, a second power supply path for supplying a voltage boosted by the booster circuit section to the sensor section, and a second switch means provided on the second power supply path.

  Furthermore, it has a control means for performing ON / OFF control of the first switch means and the second switch means.

  The control means monitors the battery voltage, and when the battery voltage is equal to or higher than a predetermined threshold value, the first switch means is ON-controlled when the sensor unit is driven to control the battery voltage. Give to the department. When the battery voltage is less than a predetermined threshold value, the second switch means is ON-controlled when the sensor unit is driven, and the voltage boosted by the booster circuit unit is applied to the sensor unit.

  If the battery voltage becomes less than the predetermined threshold at the end of battery use, the battery voltage will be insufficient for sensor drive, so by using the boosted voltage, normal operation is possible at the end of battery use. Can be extended. In addition, at a normal time other than the end of the use of such a battery, the battery consumption loss can be reduced by using the battery voltage. Accordingly, the life of the battery type alarm can be extended.

  The battery type alarm device is, for example, a gas leak alarm device.

  In this case, the sensor unit is, for example, a heater resistor in a gas sensor and a step-down circuit connected in series to the heater resistor, and the step-down circuit steps down the battery voltage or the boosted voltage, and the heater resistor Is driven by the voltage after the step-down. In the case of this example, driving the sensor unit with the voltage boosted by the booster circuit unit boosts the battery voltage by the booster circuit unit and lowers the voltage by the stepdown circuit, resulting in a double loss. . On the other hand, the loss of battery consumption can be reduced by using the battery voltage during normal times as described above.

It is a circuit diagram of the battery type gas leak alarm of this example. (A), (b) is a process flowchart figure (1) of the sensor drive by a control circuit part. It is a time chart figure of a sensor drive. (A), (b) is a process flowchart figure (2) of the sensor drive by a control circuit part. (A), (b) is a process flowchart figure (3) of the sensor drive by a control circuit part. (A), (b) is a process flowchart figure (4) of the sensor drive by a control circuit part. (A), (b) is a process flowchart figure (5) of the sensor drive by a control circuit part. It is a circuit diagram of the conventional battery type gas leak alarm.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a circuit diagram of the battery-type gas leak alarm of this example.

  This is a configuration example for making it easier to understand the characteristics of the circuit configuration of the alarm device of this example by comparing with the circuit diagram of the conventional battery-type gas leak alarm device shown in FIG. It is not limited to. Moreover, it is not limited to a gas leak alarm device, but can be applied to other alarm devices such as a fire alarm device. However, it goes without saying that this is limited to battery-powered alarms.

  Of the various components of the circuit of the battery-type gas leak alarm 10 of this example shown in FIG. 1, the same reference numerals are assigned to the same components as those of the conventional circuit shown in FIG. The description will be omitted or simplified.

  In FIG. 1, a battery unit 1 is a main power source for a gas leak alarm 10 as in the prior art, and is also a 3 V voltage power source in this example. Further, the gas sensor 2 has the same configuration as the conventional one, and has a sensor resistance 2a and a heater resistance 2b. Further, the configuration in which the load resistor R1 and the switch SW3 are connected in series with respect to the sensor resistor 2a is the same as the conventional one. Similarly, the configuration in which the switch SW1, the first constant voltage circuit unit 6, and the switch SW2 are connected in series with respect to the heater resistor 2b is the same as the conventional one.

  Further, an alarm unit 4 having an alarm sound output unit 4a such as a buzzer, an alarm display unit 4b such as an LED, an external alarm output unit 4c that is an interface for outputting a signal to the outside, and the alarm unit The control processing of the control circuit unit 11 for 4 may be the same as the conventional one. The ambient temperature detection unit 5 and the control process corresponding to the ambient temperature may be the same as the conventional one.

  The control circuit unit 11 performs substantially the same processing as that of the conventional control circuit unit 3, but will be described later with reference to FIGS. 2 (a), 2 (b), 4 (a), 4 (b), and 5 (a). ), (B), FIG. 6 (a), (b), FIG. 7 (a), (b) and the like. This is to execute processing of any one or more flowcharts.

  The control circuit unit 11 is a microcomputer or the like, and a CPU or the like executes a predetermined application program stored in advance in its built-in memory. (B), FIG. 4 (a), (b)-The process of flowcharts, such as FIG. 7 (a), (b), is implement | achieved.

  As for the input / output terminals of the control circuit unit 11, the same reference numerals are assigned to the terminals substantially the same as those of the conventional control circuit unit 3, and the difference between the output terminal OUT2 and the input terminal AD1 shown in FIG. It is a point provided. The illustrated switch SW4 is ON / OFF controlled by the ON / OFF output from the output terminal OUT2. The input terminal AD1 is connected to the battery unit 1, and the control circuit unit 11 monitors the voltage (power supply voltage) of the battery unit 1.

  Here, in this circuit, a booster circuit unit 12 is provided instead of the second constant voltage circuit unit 7 in the conventional circuit of FIG. However, since the booster circuit has been cited as an example of the second constant voltage circuit unit 7 in the prior art, it may be considered the same as the conventional one.

  However, regarding the driving of the heater resistor 2b, power supply is conventionally performed with the boosted voltage of the booster circuit unit 12 even during normal operation. However, in this circuit, the voltage (battery voltage) of the battery unit 1 is normally used in the gas sensor 2. To the heater resistance 2b. For example, at the end of the period, the voltage (VDD) boosted by the booster circuit unit 12 is applied to the heater resistor 2b. The “giving” does not necessarily mean that the battery voltage or the boosted voltage (VDD) is directly applied to the heater resistor 2b. In the example of FIG. The voltage is lowered to 2.0V or the like, and this 2.0V or the like is applied to the heater resistor 2b.

  In order to realize the above, a configuration related to the switch SW4 is newly provided, and FIGS. 2A, 2B, 4A, and 4B to 7 described later by the control circuit unit 11 are used. The processing of the flowcharts such as (a) and (b) is executed.

  That is, first, in this circuit, as a power supply route to the heater resistor 2b of the gas sensor 2, a route for applying a boosted voltage (VDD) by the booster circuit unit 12 to the heater resistor 2b via the switch SW1, and a battery of the battery unit 1 Two power supply paths of a route for applying a voltage to the heater resistor 2b via the switch SW4 are configured.

  Similarly to the operation of the control circuit unit 3 described in the prior art, the control circuit unit 11 also drives the gas sensor 2 for a certain period of time (for example, at the timing shown in FIG. 3). One of the switch SW1 and the switch SW4 is ON-controlled to supply power to the first constant voltage circuit unit 6 through one of the two routes, and the heater resistance 2b of the gas sensor 2 is set to about 2V. It is to be driven.

  Note that, regardless of which of the switches SW1 and SW4 is turned on, the switch SW2 is turned on at the same timing. The ON / OFF control for the switch SW2 is the same as that of the conventional control circuit unit 3. Further, regarding the sensor resistance 2a of the gas sensor 2, the switch SW3 is ON / OFF controlled in the same manner as the conventional control circuit unit 3, and this is not particularly described.

  As shown in the figure, the switches SW1 and SW4 are pnp transistors, and the switches SW2 and SW3 are npn transistors.

  2A and 2B are sensor drive flowcharts (No. 1) in the control circuit unit 11. FIG.

  FIG. 2A is a flowchart at the start of sensor driving, and FIG. 2B is a flowchart at the end of sensor driving. As shown in FIG. 3, during a predetermined sensor driving time T2 (here, 100 ms) every predetermined sensor driving cycle T1 (for example, a value within a range of 20 to 60 seconds; here, 60 seconds). The gas sensor 2 is driven.

  The process of FIG. 2A is executed every sensor driving cycle T1, and is executed immediately before the sensor driving time T2 (100 ms). On the other hand, the process of FIG. 2B is executed immediately after the sensor drive time T2 (100 ms).

  First, the processing of FIG. 2B will be described.

  This process waits until the sensor driving for the sensor driving time T2 (100 ms) is completed (steps S5 and NO are repeated). When the sensor driving is completed (step S5, YES), first, based on the input to the input terminal AD1, The output voltage (battery voltage; power supply voltage) of the battery unit 1 is measured (step S6). And it is determined whether this battery voltage became less than the predetermined threshold value (predetermined value) preset (step S7).

  This predetermined value is arbitrarily set in advance to a voltage value lower than the output voltage (3 V) of the battery unit 1 and higher than a voltage (eg, 2.2 V) at which this circuit does not operate normally. It is. For example, as described in the conventional problem, for example, when the voltage of the battery unit 1 becomes less than 2.2 V, even if the above-described “chopper control” is performed, the first constant voltage circuit unit 6 The output cannot be maintained at 2.0 V and cannot operate normally.

  If the output voltage of the battery unit 1 is less than the predetermined threshold value (battery voltage <predetermined value) (step S7, YES), it is determined that “battery voltage drop established by sensor driving” (step S8). Then, this determination result is held. For example, a flag indicating whether battery voltage drop is established / not established is prepared in advance, and this flag is turned on when step S8 is executed. Then, this process ends.

  The flag is referred to as needed by another process (not shown), and when the flag is on, a warning (notification) of a battery voltage drop is performed. This is notified, for example, by a voice message indicating a voltage drop by controlling the alarm unit 4 or an LED lighting / flashing pattern (predetermined arbitrarily).

  On the other hand, if the output voltage of the battery unit 1 is equal to or higher than the predetermined threshold value (battery voltage ≧ predetermined value) (step S7, NO), the process ends without performing the process of step S8. Therefore, in this case, for example, the flag remains off.

  After completion of the process of FIG. 2B, the process of FIG. 2A is executed immediately before the start of the next sensor driving time T2.

  As described above, the process of FIG. 2A is executed every sensor driving cycle T1. Therefore, first, it is determined whether or not the sensor drive cycle T1 has elapsed since the previous sensor drive, that is, whether or not the sensor drive start timing has come. Until the sensor driving start timing is reached, the determination NO in step S1 is repeated. When the sensor driving start timing is reached (step S1, YES), it is determined whether or not the battery voltage is decreasing (step S2). For example, referring to the flag, if the flag is on, it is determined that the battery voltage is decreasing (step S2, YES).

  When it is determined that the battery voltage is not decreasing (for example, when the flag is off) (step S2, NO), the heater resistor 2b is driven by the battery unit 1 (power supply voltage) (step S3). That is, the switch SW4 is turned on during the sensor driving time T2 (100 ms). In other words, during the sensor driving time T2, the switch SW4 is ON-controlled to apply the battery voltage to the heater resistor 2b. Although not described one by one, the switches SW2 and SW3 are also turned on during the sensor driving time T2 (100 ms) as in the conventional case.

  On the other hand, when it is determined that the battery voltage is decreasing (for example, when the flag is on) (step S2, YES), the heater resistor 2b is driven by the boosted voltage boosted by the booster circuit unit 12 (step S4). That is, the switch SW1 is turned on during the sensor driving time T2 (100 ms). In other words, during the sensor driving time T2, the switch SW1 is ON-controlled to give the boosted voltage VDD to the heater resistor 2b. Of course, the switches SW2 and SW3 are also turned on during the sensor driving time T2 (100 ms), as in the prior art.

  FIG. 3 shows a time chart of sensor driving by the process of FIG.

  As shown in the figure, the gas sensor 2 is driven at a predetermined sensor driving cycle T1, and the sensor driving time T2 is 100 ms here. And the process of said step S6, S7 is performed at the end of this sensor drive time T2. That is, the power supply voltage of the battery unit 1 is read to check whether the battery voltage value is less than a predetermined value.

  If the battery voltage value is equal to or higher than the predetermined value, it is regarded as normal (during the first sensor driving shown in FIG. 3), and the process of step S8 is not performed. Thus, at the time of the second sensor driving shown in FIG. 3, the determination in step S2 is NO, so the sensor is driven with the battery voltage.

  On the other hand, when the battery voltage value is less than the predetermined value, it is considered that the battery voltage has dropped (abnormal) (during the second sensor driving shown in FIG. 3), and the process of step S8 is executed. Thus, in the third sensor driving shown in FIG. 3, the determination in step S2 is YES, so that the sensor is driven with the output voltage (boosted voltage VDD) of the booster circuit unit 12.

  In addition, when the process of step S4 is performed, you may make it not perform the process of FIG.2 (b) after that. As a result, the flag remains on, the determination in step S2 is always YES, and the processing in step S4 is continued. At the end of battery use, when the battery voltage drops to some extent, the sensor drive is switched to the boosted voltage (VDD). After that, the sensor is driven to the boosted voltage (VDD) until the function stops. That is, unnecessary determination processing (the processing in FIG. 2B) is not executed.

  However, the present invention is not limited to this example, and even when the process of step S4 is executed, the process of FIG. This is because the battery voltage may temporarily drop abnormally for some reason. Even in this case, switching to sensor driving with the boosted voltage (VDD) by mistake before the end of the cycle will occur. Can be avoided.

  However, in this case (referred to as Modified Example 1), it is desirable to slightly change the process of FIG.

  FIGS. 4A and 4B are sensor driving flowcharts in the control circuit unit 11 of the first modification. FIG. 4A is a flowchart at the start of sensor driving, and FIG. 4B is a flowchart at the end of sensor driving.

  Here, in FIGS. 4 (a) and 4 (b), the same steps as those in FIGS. 2 (a) and 2 (b) are denoted by the same step numbers, and the description thereof is omitted. 4A is the same as FIG. 2A, and the description thereof is omitted. As shown in the figure, the process of FIG. 4B is almost the same as that of FIG. 2B, and the only difference is that the process of step S9 is added.

  That is, in the case of FIG. 2B, after the processing of step S8 is executed once, even if the determination of NO is made in step S7, the flag is not turned OFF. (There is no point in executing the process of FIG. 2B. Therefore, as described above, the process of FIG. 2B may not be executed. However, for example, the process of step S11 described later may be executed immediately after the process of step S4). As a result, the processing load is reduced, so that the power consumption can be suppressed and the battery life can be extended.

  On the other hand, in FIG.4 (b), when determination of step S7 becomes NO, the process of step S9 is performed. That is, it is determined that “battery voltage drop due to sensor driving is not established” (step S9). Then, this determination result is held. For example, the flag indicating the establishment / non-establishment of the battery voltage drop is turned off.

  According to the processing of FIGS. 4A and 4B described above, when the battery voltage temporarily drops abnormally for some reason, step S7 is YES and step S8 is executed during the voltage drop. Step S2 becomes YES, and the sensor drive by the boosted voltage (VDD) is performed. In other words, when the sensor unit (including the heater resistor 2b) is driven, the switch SW1 is ON-controlled to supply the voltage (VDD) boosted by the booster circuit unit 12 to the sensor unit (heater resistor 2b and the like).

  However, if the battery voltage returns to a normal state because of a temporary abnormality, step S7 is NO and step S9 (flag off, etc.) is executed. Thereby, step S2 becomes NO, and the sensor driving state (normal state) by the battery voltage is returned. The normal state is a state in which the battery voltage is applied to the sensor unit (such as the heater resistor 2b) by controlling the switch SW4 to be ON when the sensor unit (including the heater resistor 2b) is driven.

  Then, when the end stage is reached, the state in which step S7 is YES and step S8 is executed continues. Therefore, the state in which step S2 is YES continues, and thus the state in which the sensor driving by the boosted voltage (VDD) is continued, basically returning to the sensor driving state by the battery voltage. There is nothing.

  In the battery-type alarm device, there is a possibility that the battery voltage temporarily drops due to some cause. However, according to the configuration of the first modification, the sensor based on the boosted voltage (VDD) before the end due to the abnormal drop. Even if the situation of switching to driving occurs, it is only temporary and returns to the sensor driving state by the battery voltage again.

  In the above, the modification 1 which is one of the modifications has been described. Hereinafter, other modifications will be described.

  First, Modification 2 will be described below.

  In the first modified example, although it is temporary, it may be switched to the sensor driving by the boosted voltage (VDD) even before the end stage. On the other hand, in the second modification, even if the battery voltage temporarily decreases abnormally for some reason, the situation is that the sensor driving by the boosted voltage (VDD) is erroneously switched before the end stage. Can be avoided.

  5A and 5B are sensor driving flowcharts in the control circuit unit 11 according to the second modification. FIG. 5A is a flowchart at the start of sensor driving, and FIG. 5B is a flowchart at the end of sensor driving.

  Here, in FIGS. 5 (a) and 5 (b), the same steps as those in FIGS. 2 (a) and 2 (b) are denoted by the same step numbers, and description thereof is omitted. 5A is the same as FIG. 2A, and the description thereof is omitted. Further, as shown in the figure, the process of FIG. 5B is almost the same as that of FIG. 2B, and the only difference is that the process of step S10 is added.

  That is, in the process of FIG. 5B, the process of step S10 is added between step S7 and step S8. Even when step S7 is YES, the process of step S8 is not immediately performed, but the process of step S8 is performed only when the determination of step S10 is YES. In step S10, it is determined whether or not the determination of YES in step S7 is continued for a predetermined number of times (N times; N may be any integer if it is an integer equal to or greater than 2 and may be arbitrarily determined). (Step S10).

  For example, using a counter, the counter is incremented by +1 every time the determination in step S7 is YES and reset to '0' every time the determination in step S7 is NO. In step S10, the count value is compared with the predetermined number N to determine whether or not “count value ≧ predetermined number N”.

  If step S7 is YES continuously for a predetermined number of times (for example, if “count value ≧ predetermined number N”), the determination in step S10 is YES and the process in step S8 is performed. Executed. If not (NO in step S10), the process of step S8 is not executed and the present process ends.

  In this process, since there is no process for turning off the flag, once the flag is turned on in step S8, the sensor is driven by the boost voltage (VDD) all the time thereafter. This is because when the step S7 is YES continuously for a predetermined number of times or more, it can be regarded as the end of battery use.

  In addition, it can be considered that it is not necessary to execute the process of FIG. 5B (or the process of FIG. 5A) once the flag is turned on. Thus, although not shown, for example, the process of step S11 described later may be executed immediately after the process of step S4. As a result, the processing load is reduced, so that the power consumption can be suppressed and the battery life can be extended.

  Next, Modification 3 will be described below.

  In the third modification example, when “the process of step S4 is executed (in other words, when it is detected that the battery voltage is less than the predetermined value), the process of FIG. 2B is not executed thereafter. It corresponds to doing so.

  6A and 6B are sensor driving flowcharts in the control circuit unit 11 of the third modification. FIG. 6A is a flowchart at the start of sensor driving, and FIG. 6B is a flowchart at the end of sensor driving.

  Here, in FIGS. 6A and 6B, substantially the same processes as those in FIGS. 2A and 2B are denoted by the same step numbers, and description thereof is omitted. 6B is the same as FIG. 2B, and the description thereof is omitted. Further, as shown in the figure, the process of FIG. 6A is almost the same as that of FIG. 2A, and the only difference is that the process of step S11 is added.

  That is, in FIG. 6A, the heater resistance 2b is driven by the boosted voltage VDD (step S4) by determining that the battery voltage is being lowered (flag on) (step S2, YES), and then the mode is further changed to a predetermined mode. The process to transfer is performed (step S11). This predetermined mode is, for example, a mode in which “the process of FIG. 2B is not executed” (the battery voltage is not monitored) described above. As a result, the flag remains on, the determination in step S2 is always YES, and the processing in step S4 is continued. Then, the processing load is reduced as much as the processing of FIG.

  However, the present invention is not limited to this example. As the predetermined mode, for example, “a mode in which the processing of FIGS. 2A and 2B is not executed and the heater resistor 2b is always driven by a boosted voltage (SW1 is always turned on when the sensor is driven)” is previously set. It may be prepared to switch to the predetermined mode when step S4 is executed. In this case, since not only the process of FIG. 2B but also the process of FIG. 2A is not executed, the processing load is further reduced accordingly.

  However, in the above-described modification 3, for example, it is impossible to cope with a situation where the battery voltage temporarily drops due to some cause as described above, and when such an abnormality occurs, the boost voltage is increased even after the abnormal state is resolved. Thus, the heater resistor 2b is driven.

  On the other hand, although it may be possible to cope with this by adding the process of step S10, in the following modification 4, determination using two types of threshold values, the first threshold value and the second threshold value described below, is performed. I will respond.

“First threshold value”: Arbitrary, provided that the voltage value is lower than the output voltage (battery voltage; 3V) of the battery unit 1 and higher than the voltage at which the circuit does not operate normally (eg, 2.2V). Set to.
“Second threshold value”; arbitrarily set on condition that the voltage value is lower than the first threshold value and higher than a voltage (eg, 2.2 V) at which the circuit does not operate normally. For example, it shows the final state of battery use.

  The first threshold value may be considered to correspond to the “predetermined value” used in the determination in step S7, but is not limited to this example.

  FIGS. 7A and 7B are sensor driving flowcharts in the control circuit unit 11 of the fourth modification. FIG. 7A is a flowchart at the start of sensor driving, and FIG. 7B is a flowchart at the end of sensor driving.

  Here, in FIGS. 7A and 7B, substantially the same processes as those in FIGS. 2A and 2B are denoted by the same step numbers, and description thereof is omitted. Accordingly, as illustrated, the process of FIG. 7A is obtained by adding the processes of steps S23 and S24 to the process of FIG. Further, as shown in the figure, the process of FIG. 7B is obtained by adding step S20 instead of step S7 of FIG. 2B and further adding processes of steps S21 and S22.

  First, FIG. 7B will be described.

  In FIG. 7B, if the determination in step S5 is YES and step S6 is executed, then, instead of the determination of “battery voltage <predetermined value?” In step S7 of FIG. Then, “battery voltage <first threshold?” Is determined (step S20). However, as described above, the first threshold value may be regarded as corresponding to the “predetermined value”. In this case, step S20 may be regarded as substantially the same as step S7.

  If the battery voltage is less than the first threshold value (step S20, YES), the process of step S8 is performed, and subsequently, “battery voltage <second threshold value?” Is determined (step S21). If the battery voltage is greater than or equal to the second threshold value (step S21, NO), this process is terminated as it is. On the other hand, if the battery voltage is less than the second threshold (step S21, YES), it is determined that “the terminal state is established” (step S22). Specifically, the processing in step S22 is, for example, turning on a flag indicating “establishment of final state” (referred to as a second flag), but is not limited to this example.

  Next, FIG. 7A will be described.

  If the process of FIG. 7A is executed after the determination of step S20 is YES, the determination of step S2 is YES and the process of step S4 is performed. Then, following the process of step S4, it is determined whether or not the terminal state is reached (step S23). For example, with reference to the second flag, it is determined that the terminal state is in the final state if the second flag is on, and the terminal state is not determined if the second flag is off.

  If it is determined that the terminal state is not in the final state (step S23, NO), this process is terminated. If it is determined that the terminal state is reached (step S23, YES), the process proceeds to a predetermined mode (step S24). Here, the “predetermined mode” may be substantially the same as the “predetermined mode” in step S11, for example. That is, the “predetermined mode” may be a mode in which “the process of FIG. 7B is not executed” (battery voltage is not monitored), for example. Alternatively, the “predetermined mode” is a “mode in which the processing of FIGS. 7A and 7B is not executed and the heater resistor 2b is always driven by the boosted voltage (SW1 is always turned on during driving)”. Also good.

  Although not shown in FIG. 7B, when the determination in step S20 is NO, the process of step S9 may be executed in substantially the same manner as in FIG. 4B. . Thus, for example, even if the battery voltage becomes lower than the first threshold value due to the temporary abnormal decrease in the battery voltage as described above, it is determined that the battery voltage drop is established as long as the battery voltage does not become lower than the second threshold value. Even if the boosted voltage is used, when the battery voltage returns to the normal state, the battery voltage is returned to the normal state.

  As described above, in the modified example 4, by using the first threshold value used for switching between the battery voltage and the boosted voltage and the second threshold value used for determining whether or not the battery is in the final state, If it is determined that the battery is in its final stage, the battery voltage is not monitored thereafter. As a result, the processing load can be reduced, power consumption can be suppressed, and the normal operation time (battery life) can be extended. Moreover, it is possible to cope with a situation where the battery voltage temporarily decreases abnormally for some reason. That is, it is possible to avoid a situation in which the heater resistor 2b is driven by the boosted voltage all the time thereafter, although it is not yet the final stage. Even if the heater resistance 2b is temporarily driven by the boosted voltage, the heater resistance 2b can be driven again by the battery voltage (normal state). As a result, it is possible to avoid a situation where the normal operation time is shortened.

  Needless to say, power consumption is greater when driven by a boosted voltage than when driven by a battery voltage.

  In addition, the above-mentioned “driving the heater resistor 2b with the boosted voltage” corresponds to giving the boosted voltage to the sensor unit (heater resistor 2b or the like) when the sensor unit (including the heater resistor 2b) is driven. Similarly, “to drive the heater resistor 2b by the battery voltage” corresponds to applying a battery voltage to the sensor unit (heater resistor 2b or the like) when the sensor unit (including the heater resistor 2b) is driven.

  As described above, in the present technique, any one of the processes in FIGS. 2A, 2B, 4A, 4B to 7A, 7B is performed with the configuration shown in FIG. By doing so, regarding the driving of the gas sensor 2, it is possible to reduce the loss of battery consumption by applying the battery voltage of the battery unit 1 in normal times, and it is normal because switching is performed to give the boosted voltage of the booster circuit at the end of battery use. The operating time can be extended. As a result, the life of the alarm device can be extended. Furthermore, it helps to meet the above-mentioned regulations.

  In other words, as described in the conventional problem, regarding battery-powered alarm devices, it is stipulated that battery replacement is not permitted (thus, the alarm device itself is replaced when the life is reached) and that it can operate normally for more than 5 years. Achieving a long service life by the technique helps to satisfy this regulation sufficiently.

  The configuration shown in FIG. 1 and the processes shown in FIGS. 2A and 2B are examples, and are not limited to this example. Moreover, the application destination of this method is not limited to a gas leak alarm device, and may be, for example, a fire alarm device.

According to the battery type alarm device of the present invention, it relates to a battery type alarm device, in particular, with respect to the configuration related to sensor driving, the loss of battery consumption can be reduced, and the time during which normal operation is possible at the end of battery use can be reduced. The life of the alarm device can be extended.

Claims (6)

A battery-type alarm device having at least a sensor part and a battery,
A booster circuit for boosting the battery voltage;
A first power supply path for supplying the battery voltage to the sensor unit; and first switch means provided on the first power supply path;
A second power supply path for supplying a voltage boosted by the booster circuit section to the sensor section; and second switch means provided on the second power supply path;
Control means for ON / OFF control of the first switch means and the second switch means,
The control means monitors the battery voltage, and when the battery voltage is equal to or higher than a predetermined threshold value, the first switch means is ON-controlled when the sensor unit is driven to send the battery voltage to the sensor unit. When the battery voltage is less than a predetermined threshold, the second switch means is controlled to be ON when the sensor unit is driven, and the voltage boosted by the booster circuit unit is applied to the sensor unit. A battery-powered alarm. The sensor unit is a heater resistor in a gas sensor and a step-down circuit connected in series to the heater resistor,
The battery type alarm device according to claim 1, wherein the step-down circuit steps down the battery voltage or the boosted voltage, and the heater resistor is driven by the voltage after the step-down. A battery-type alarm device having at least a sensor part and a battery,
A booster circuit for boosting the battery voltage;
A first power supply path for supplying the battery voltage to the sensor unit; and first switch means provided on the first power supply path;
A second power supply path for supplying a voltage boosted by the booster circuit section to the sensor section; and second switch means provided on the second power supply path;
Control means for ON / OFF control of the first switch means and the second switch means,
The control means monitors the battery voltage, and when it is detected that the battery voltage is equal to or higher than a predetermined threshold, the first switch means is ON-controlled when the sensor unit is driven to control the battery voltage. Is supplied to the sensor unit, and when the battery voltage is detected to be less than a predetermined threshold, the second switch means is ON-controlled when the sensor unit is driven and boosted by the booster circuit unit. Voltage is applied to the sensor unit;
Even when it is detected that the battery voltage is less than a predetermined threshold, the control means continues to monitor the battery voltage, and when the battery voltage returns to a predetermined threshold or higher, A battery-type alarm device, wherein the battery voltage is supplied to the sensor by controlling the first switch means to be ON when the sensor unit is driven. A battery-type alarm device having at least a sensor part and a battery,
A booster circuit for boosting the battery voltage;
A first power supply path for supplying the battery voltage to the sensor unit; and first switch means provided on the first power supply path;
A second power supply path for supplying the voltage boosted by the booster circuit section to the sensor section; and second switch means provided on the second power supply path;
Control means for ON / OFF control of the first switch means and the second switch means,
The control means monitors the battery voltage every predetermined period, and when the battery voltage is detected to be equal to or higher than a predetermined threshold, the first switch means is ON-controlled when the sensor unit is driven. When the battery voltage is applied to the sensor unit and it is continuously detected N times or more that the battery voltage is less than a predetermined threshold (N: an arbitrary integer of 2 or more), the subsequent sensor A battery-type alarm device characterized in that when the unit is driven, the second switch means is ON-controlled to give the voltage boosted by the boosting circuit unit to the sensor unit. A battery-type alarm device having at least a sensor part and a battery,
A booster circuit for boosting the battery voltage;
A first power supply path for supplying the battery voltage to the sensor unit; and first switch means provided on the first power supply path;
A second power supply path for supplying a voltage boosted by the booster circuit section to the sensor section; and second switch means provided on the second power supply path;
Control means for ON / OFF control of the first switch means and the second switch means,
The control means monitors the battery voltage, and when it is detected that the battery voltage is equal to or higher than a predetermined first threshold, the first switch means is ON-controlled when the sensor unit is driven to A battery voltage is applied to the sensor unit, and when it is detected that the battery voltage is less than a predetermined first threshold, the second switch means is controlled to be ON when the sensor unit is driven, and the booster circuit unit The voltage boosted by is applied to the sensor unit,
When it is detected that the battery voltage is less than a predetermined second threshold value, the control unit does not monitor the battery voltage thereafter, and is boosted by the booster circuit unit when the sensor unit is driven. A battery-type alarm device, wherein a voltage is applied to the sensor unit. A battery-type alarm device having at least a sensor part and a battery,
A booster circuit for boosting the battery voltage;
A first power supply path for supplying the battery voltage to the sensor unit; and first switch means provided on the first power supply path;
A second power supply path for supplying a voltage boosted by the booster circuit section to the sensor section; and second switch means provided on the second power supply path;
Control means for ON / OFF control of the first switch means and the second switch means,
The control means monitors the battery voltage,
When it is detected that the battery voltage is equal to or higher than a predetermined first threshold value, the first switch means is ON-controlled when the sensor unit is driven, and the battery voltage is supplied to the sensor unit.
When it is detected that the battery voltage is less than a predetermined first threshold value, the second switch means is ON-controlled during driving of the sensor unit, and the voltage boosted by the booster circuit unit is detected by the sensor. The battery-type alarm device is characterized in that the battery voltage is not monitored and thereafter the voltage boosted by the booster circuit unit is always supplied to the sensor unit when the sensor unit is driven.

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