JP2004150320A - Battery voltage reduction alarm buzzer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery voltage reduction alarm buzzer device which uses informing sound easy to be perceived by an operator. <P>SOLUTION: This alarm buzzer device 1 comprises a normal circuit and a trouble circuit. In the normal circuit, a cathode of a Zener diode ZD and one end of a first resistor R1 are respectively connected to a positive terminal a of a battery B, a collector of a first transistor T1 is connected to the other end of the first resistor R1, a negative terminal of the battery B is connected to an emitter of the first transistor T1, one end of a second resistor R2 is connected to a base of the first transistor T1, and an anode of the Zener diode ZD and the negative terminal of the battery B are respectively connected to the other end of the second resistor R2. In the trouble circuit, an input end of a buzzer 2 is connected to the one end of the first resistor R1, a collector of a second transistor T2 is connected to an output end of the buzzer 2, the negative terminal of the battery B is connected to an emitter of the second transistor T2, and the other end of the first resistor R1 is connected to a base of the second transistor T2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a low battery alarm buzzer for a battery mounted on an automobile such as a bus.
[0002]
[Prior art]
As an exercise that can actively address environmental issues such as the atmospheric environment and global warming, "idling stop exercises" are implemented by bus companies and the like.
This movement is to stop the exhaust gas by idling by turning off the engine or the like when stopping by a signal or parking in a garage or terminal.
On the other hand, there has been a problem that the voltage of the battery decreases as the number of engine starts increases due to the execution of this exercise.
[0003]
Current bus vehicles are equipped with many electric devices such as lighting, air conditioners, toll boxes, gear boxes, etc., and a drop in battery voltage will cause malfunctions of those devices. .
For example, if the engine is started while the toll box is operating, the operation of the toll box will stop, causing an accident such as a bill being bitten by a machine, or the engine cannot be started, resulting in a road failure. Actually, such accidents have occurred. Such an accident may impair passenger confidence.
[0004]
As a method of solving such a problem, a technique of allowing a driver to visually recognize a discharge state with a lamp has been conventionally known (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP 11-069642 A (paragraph 0020, FIG. 2)
[0006]
[Problems to be solved by the invention]
However, in the method of visually confirming with a lamp, there is a fear that a crew may miss lighting of the lamp.
Also, as in Patent Document 1, even if the discharge state of the battery is turned on by a lamp and the driver notices it, it is unknown to the driver how much the voltage drops (see Patent Document 1, (See paragraph 0027), and there is a risk of giving unnecessary pressure.
Further, when the lamp is turned off when the voltage between the terminals of the battery falls below the voltage at which the engine can be started (see Patent Document 1, paragraph 0027), there is no room for taking good measures, and in this respect too, the driver is useless. This will create pressure and even annoy the passengers.
[0007]
Therefore, the present invention has been made in view of the above circumstances, and instead of using a lamp that is easily overlooked, a warning sound that is most easily perceived by the driver is used, and a mental margin is provided so that the crew can take good post-measures. It is an object of the present invention to provide a low battery alarm buzzer device that can provide the following.
[0008]
[Means for Solving the Problems]
To achieve the above object, a battery voltage drop warning buzzer according to the present invention (hereinafter referred to as a warning buzzer) has the following circuit configuration.
That is, the cathode of the Zener diode is connected to the plus terminal of the battery, and the minus terminal of the battery is connected to the anode.
One end of the first resistor and the input end of the buzzer are connected to the cathode of the Zener diode, respectively.
The collector of the first transistor is connected to the other end of the first resistor, the negative terminal of the battery is connected to the emitter of the transistor, and the base of the second transistor is connected to the other end of the first resistor.
The output terminal of the buzzer is connected to the collector of the second transistor, and the emitter of the transistor is connected to the negative terminal of the battery.
An anode terminal of the Zener diode is connected to a base of the first transistor via a second resistor.
[0009]
If the reverse voltage between the positive terminal and the negative terminal of the battery is equal to or higher than the Zener voltage, the Zener diode constituting the present invention is turned on, and the reverse voltage between the positive terminal and the negative terminal of the battery becomes the Zener voltage. If it is below, it is off.
Thus, if the reverse voltage between the battery terminals is sufficiently higher than the Zener voltage, the first transistor will be turned on and the second transistor will not be turned on, and the battery current will flow from its plus terminal to the first resistor, The buzzer does not sound through the first transistor to the minus terminal.
On the other hand, if the reverse voltage between the battery terminals is lower than the Zener voltage, the first transistor is turned off and the second transistor is turned on, so that the battery current flows from its plus terminal to the input / output terminal of the buzzer, The signal reaches the minus terminal via the second transistor, and the buzzer sounds.
Therefore, the abnormality of the battery can be recognized by the buzzer or the notification sound that is easily perceived by the driver (also referred to as a crew member) using the buzzer or the earphone incorporating the buzzer.
[0010]
In the above invention, the Zener voltage is set to be substantially the same as the voltage at which the vehicle can run for about one hour depending on the battery capacity of the vehicle (the invention according to claim 2).
Therefore, the buzzer is turned on when the vehicle can be driven for about one hour by the remaining capacity of the battery. If the buzzer does not go off while the engine is running, the battery is defective.
That is, since the buzzer is activated before the battery capacity is completely reduced and when the battery capacity is large enough to return the car to a base such as a garage, contacting the base and the like after You can take measures and exchange the car at the start and end points.
[0011]
In the above invention, a capacitor is connected between the anode of the Zener diode and the negative terminal of the battery (the invention of claim 3).
This capacitor will be charged during normal normal operation of the battery. Therefore, for example, when the engine is started after the execution of the "idling stop motion" during the normal operation, even if the voltage between the battery terminals is rapidly reduced, the capacitor is discharged, and a forward voltage is applied to the zener diode. Therefore, the first transistor can be turned on, and the buzzer does not turn on.
Therefore, there is no needless misunderstanding for the crew.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The configuration of each of the above inventions will be described in detail with reference to the drawings.
FIG. 1 is a circuit diagram of the alarm buzzer device according to the first embodiment, FIG. 2 is a circuit diagram of the alarm buzzer device according to the second embodiment, and FIG. 3 is a mounting state diagram of the alarm buzzer device.
In each of the drawings, components denoted by the same reference numerals indicate the same configuration. Further, a bus vehicle is assumed as a vehicle provided with the alarm buzzer device according to each embodiment.
[0013]
The circuit of the alarm buzzer device 1 shown in FIG. 1 includes a normal circuit that operates when the voltage between the positive terminal and the negative terminal of the battery is equal to or higher than the Zener voltage, and a circuit that operates when the voltage between the positive terminal and the negative terminal of the battery is equal to or lower than the Zener voltage. It consists of a trouble circuit that works when
[0014]
In the normal circuit, the cathode of the Zener diode ZD and one end of the first resistor R1 are connected to the plus terminal a of the battery B, and the collector of the first transistor T1 is connected to the other end of the first resistor R1. The negative terminal of the battery B is connected to the emitter of the transistor T1, one end of a second resistor R2 is connected to the base of the transistor T1, and the other end of the second resistor R2 is connected to the anode of the Zener diode ZD and the battery. The negative terminals of B are connected to each other.
[0015]
On the other hand, in the trouble circuit, one end of the first resistor R1 is connected to the input terminal of the buzzer 2, the output terminal of the buzzer 2 is connected to the collector of the second transistor T2, and the emitter of the transistor T2 is connected to the battery. , And the other end of the first resistor R1 is connected to the base of the transistor T2.
[0016]
Next, the operation of the normal circuit will be described.
During normal operation in which the power consumption of the battery B is charged and recovered by the generator of the vehicle, the voltage between the plus terminal a and the minus terminal b of the battery B becomes equal to or higher than the zener voltage of the zener diode ZD.
Therefore, a reverse current flows through the Zener diode ZD, and the Zener diode ZD is turned on (communicated), a predetermined voltage is applied between the other end of the second resistor R2 and the minus terminal b of the battery B, and the second resistor R2 A bias voltage is applied from one end to the base of the first transistor T1.
As a result, the first transistor T1 is turned on, and the battery current flows from the plus terminal a of the battery B to the first resistor R1, and from the collector of the first transistor T1 to the emitter and the minus terminal b of the battery B. Flows.
On the other hand, the battery current dropped by the first resistor R1 is difficult to flow from the base to the emitter due to the internal resistance of the second transistor T2, and the second transistor T2 does not turn on. Therefore, the buzzer 2 does not sound.
[0017]
Next, the operation of the trouble circuit will be described.
When the voltage between the positive terminal a and the negative terminal b of the battery B is equal to or less than the Zener voltage of the Zener diode ZD, no reverse current flows through the Zener diode ZD, and thus the Zener diode ZD is turned off (disconnected). ), And no bias voltage is applied to the base of the first transistor T1. Therefore, the first transistor T1 is turned off.
On the other hand, due to the battery current when the Zener diode ZD is off, the base potential of the second transistor T2 rises, the second transistor T2 turns on, and the battery current flowing from the buzzer 2 to the minus terminal b of the battery B However, the buzzer 2 sounds.
[0018]
That is, the buzzer 2 sounds when the voltage between the terminals a and b of the battery B falls below the Zener voltage, and the buzzer sounds when the voltage between the terminals a and b of the battery B recovers above the Zener voltage. 2 is set to stop ringing.
Therefore, a crew member can recognize a voltage drop due to a failure of the battery B, an alternator, a relay, a wiring failure, or the like by using the buzzer 2 or an earphone incorporating the buzzer 2.
[0019]
The Zener voltage of the Zener diode ZD is set to about 22.6V ± 0.2V. The reason is as follows.
The first is to activate the buzzer 2 before the capacity of the battery B is completely reduced so as to cause a failure on the road, and at the time when the battery has enough battery capacity to run to a base such as a garage. It is to make it.
In normal operation, it takes about 40 minutes to about 1 hour to decrease from 22.6 V to 22.0 V.
If there is such a time margin, it is possible to take good or bad measures such as contacting the base and give the crew a mental margin.
Secondly, when the voltage for operating the magnet of the gear transmission of the vehicle drops to 20 V or less, it becomes inoperable.
Third, once the engine is stopped, the starter motor cannot be started without a voltage of 20 V or more.
Fourth, the engine cannot be started because the solenoid does not operate without a voltage of 20 V or more when the engine is stopped.
[0020]
The first and second resistors R1 and R2 each have a resistance of about 3 kΩ.
[0021]
Next, a configuration of an alarm buzzer device 1A according to a second embodiment will be described with reference to FIG.
This alarm buzzer device 1A is different from the alarm buzzer device 1 in that one end is connected to the minus terminal b of the battery B, the other end is connected to the anode of the Zener diode ZD, and the second resistor 2 in that capacitors 7 respectively connected to the other ends of the capacitors 2 are provided.
The Zener diode ZD has a characteristic of turning on when a forward current is applied. When the voltage between the terminals a and b of the battery B suddenly drops during normal operation, for example, at the time of starting the engine after performing the “idling stop motion”, and the voltage drops below the Zener voltage, the capacitor 7 discharges, The first transistor T1 can be turned on, and the buzzer 2 does not turn on.
The charge retention time of the capacitor 7 is about 5 seconds, and the buzzer 2 does not sound at a voltage drop that occurs at the time of starting the engine during normal operation, so that the crew does not misunderstand that a trouble has occurred.
[0022]
The alarm buzzer device configured as described above uses one zener diode ZD, two resistors, two transistors, one buzzer and one capacitor, and is configured to be inexpensive and compact with a small number of elements. Can be. Therefore, for example, as shown in FIG. 3, it can be attached to the dashboard of the driver's seat.
In each of the above embodiments, the present invention is applied to a bus vehicle, but may be applied to a truck or the like, and is not limited to the type of vehicle.
[0023]
【The invention's effect】
According to the first aspect of the present invention, when the idling stop exercise is promoted, the driver can perform the exercise with ease.
In addition, an earphone with a buzzer may be used, and there is no shortage of confirmation like a lamp.
Also, the alarm buzzer device can be configured with a small number of elements.
[0024]
According to the second aspect of the present invention, it is possible to provide a driver with a mental margin and avoid a road breakdown.
[0025]
According to the third aspect of the present invention, even when the engine is started and the voltage between the battery terminals suddenly drops, the buzzer does not turn on and the crew does not have unnecessary misunderstanding.
[Brief description of the drawings]
FIG. 1 is a circuit diagram according to a first embodiment,
FIG. 2 is a circuit diagram according to a second embodiment,
FIG. 3 is an explanatory view of mounting a warning buzzer device.
[Explanation of symbols]
1 1A Alarm buzzer device B Battery a Positive terminal b Minus terminal ZD Zener diode R1 First resistor R2 Second resistor T1 First transistor T2 Second transistor 2 Buzzer

Claims (3)

A positive terminal of the battery is connected to a cathode of the Zener diode, and a negative terminal of the battery is connected to an anode of the Zener diode.
One end of the first resistor and the input end of the buzzer are connected to the cathode of the Zener diode, respectively.
A collector of a first transistor is connected to the other end of the first resistor, a negative terminal of the battery is connected to an emitter of the transistor, and a base of a second transistor is connected to the other end of the first resistor;
A collector of the second transistor is connected to an output terminal of the buzzer, and a negative terminal of the battery is connected to an emitter of the transistor,
A low battery alarm buzzer, wherein an anode of the Zener diode is connected to a base of the first transistor via a second resistor. 2. The battery voltage drop alarm buzzer according to claim 1, wherein the Zener voltage of the Zener diode is set to be substantially the same as a voltage at which the vehicle can run for about one hour depending on its battery capacity. . 2. The battery voltage drop alarm buzzer according to claim 1, wherein a capacitor is connected between an anode of the Zener diode and a negative terminal of the battery.

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