JPH02303330A - Power source circuit - Google Patents

Abstract

PURPOSE:To notify a user of the conditions of equipment by providing a means which does not make power and at the same time issues an acoustic warning to a user, if the residual capacity of a battery is small, when a power source switch is put in making conditions. CONSTITUTION:A battery 2 is built in equipment 1, and when a power source switch 3 gets in making conditions, if a battery residual capacity detecting circuit 4 judges that the residual capacity of the battery is small, since a current supply circuit 5 is not opened, the current is not supplied to the inner circuit of equipment 1, so the equipment 1 does not get in operating condition. At the same time with that, current is supplied to a buzzer 6 to sound it thereby notifying a user of equipment acoustically that the residual capacity of the battery 2 has become small. Hereby, in case that the power does not get in making conditions though the power source switch 3 is put in making conditions 3, the user of the equipment 1 can know clearly whether or not it is attributable to the residual capacity of the battery 2 having become small.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a power supply circuit for equipment using batteries.

[Prior Art] Conventionally, when using a built-in battery in an electronic device while charging it externally, the device is equipped with a lamp that displays the capacity of the internal battery, and when the power switch is turned on, the battery level is displayed. When the remaining battery capacity is low, the lamp flashes to warn you of the current state and remind you to continue charging. Furthermore, if the remaining capacity of the battery becomes insufficient while the device is being used continuously, some kind of warning, such as a lamp display, is displayed even in such a case. The principle of operation of such a device is
A common mechanism was to detect the voltage across the battery and activate a warning device when it fell below a certain value.

[Problem to be Solved by the Invention] Therefore, providing a warning device is a technology that has been very commonly implemented in the past, and various specific warning means have been considered, but if the user has technical Even if you are a very general user, regardless of your experience, the more frequently you use your device on a daily basis, the more you will need a user-friendly warning mechanism to determine whether the internal battery capacity is present or not. do. When considering warning means that are suitable for the usage environment in general daily life, it is not possible to realize an easy-to-use device by simply giving a warning using a lamp or a buzzer.

To summarize the above, while the 11 devices are being used continuously, the system detects a lack of capacity in the device's internal battery and gives a warning, so there is no problem for the user, and it is already commonly implemented. There is.

2. If the device is not in use and the internal power supply capacity decreases during the period of non-use, but the degree of decrease is small, when you turn on the power switch, the device will start up and immediately display a warning message. change. This also provides a warning to the user and is a commonly practiced technique.

3. The internal battery capacity of the device may decrease further, but if the capacity is insufficient to the extent that the device cannot operate normally, there will be no warning even if the power switch is turned on. As a result, the device did not show any reaction, so it was determined whether the device was malfunctioning or the battery was running low.

Even in the case of (3) above, the present invention always causes a reaction from the device to the user and warns the user, including those around the device, as to what internal capacity the device is currently being used at. The main focus is on that. Therefore, an object of the present invention is to inform the user of the status of the equipment and to warn the user of the cause of the equipment's inoperability.

[Means for Solving the Problems] The present invention provides a power supply circuit that includes at least a battery that stores internal power and a remaining capacity detection circuit of the battery, and the power supply circuit detects the power of the battery when the power switch is turned on. The device is characterized in that it is equipped with means for not turning on the power if the remaining capacity is low and at the same time issuing an acoustic warning to the user.

[Example] FIG. 1 shows an example of the present invention. A device 1 has a built-in battery 2. When the power switch 3 is turned on,
If the remaining battery capacity detection circuit 4 does not determine that the remaining capacity of the battery 2 is low, the current supply circuit 5 is opened, current is supplied to the internal circuit of the device 1, and the device is brought into operation.

On the other hand, when the power switch 3 is turned on, if the remaining battery capacity detection circuit 4 determines that the remaining capacity of the battery 2 is low, the current supply circuit 5 is not opened, so the internal circuit of the device 1 receives no current. is not supplied, and the device 1 is not put into operation. At the same time, current is supplied to the buzzer 6, and the buzzer 6
The device sounds to acoustically notify the user of the device that the remaining capacity of the battery 2 is low.

However, if the remaining capacity of the battery 2 is completely depleted, even the buzzer 6 cannot sound, so the user cannot be notified acoustically.
When the device 1 is used repeatedly after being turned off and turned off, it is unlikely that the remaining capacity of the battery 2 will be so low that the buzzer 6 will not sound when the power switch is turned on again. Since it can be said that there is no problem, there is no problem in actual use.

Additionally, if the device 1 is left unattended for a long period of time, for example 3 months or more, the user will usually be able to notice that the battery 2 is completely discharged, and the buzzer 6 will no longer sound. However, if it does, it is not a problem.

FIG. 2 shows an example of a battery remaining capacity detection circuit. FIG. 3 shows the battery voltage when battery 2 is discharging a constant current.

When the remaining capacity of the battery becomes small, the battery voltage drops rapidly. Therefore, the detected value is based on the voltage corresponding to the target battery remaining capacity, and if the voltage of battery 2 is higher than that, it is determined that battery 2 still has remaining capacity, and if the voltage of battery 2 is low, battery 2 It is determined that there is no remaining capacity.

A reference voltage υ1 is applied from a reference voltage source 8 to an inverting input of the voltage comparator 7, and a voltage of the battery 2 is applied to a non-inverting input. υ1 is set to the same voltage as the voltage at which it is determined that the remaining capacity of battery 2 is lower than the battery voltage.

When the battery 2 has remaining capacity, the non-inverting input to the voltage comparator 7 is higher than the reference voltage υl, which is the inverting input, so the detection output of the voltage comparator 7 becomes a logical high level.

When the remaining capacity of the battery 2 decreases, the non-inverting input to the voltage comparator 7 becomes lower than the reference voltage υ1 which is the inverting input, so the detection output of the voltage comparator 7 logically becomes a low level.

Although the embodiments of the present invention have been described using a secondary battery as an example, similar effects can be obtained even when a secondary battery (dry battery) is used.

[Effect of the invention] By using the power supply circuit as described above, if the power does not turn on even though the power switch is turned on, this is because the remaining capacity of the battery is getting low. The user of the device can now clearly see whether the device is working or not, and is informed of the status of the device.

[Brief explanation of drawings]

FIG. 1 is a diagram showing one embodiment of the present invention. FIG. 2 is a diagram showing an example of a battery remaining capacity detection circuit. FIG. 3 is a diagram showing the change in battery voltage when the battery 2 is discharged from a fully charged state with a constant current. l -1 Equipment 2-1 Battery 3-1 Power switch 4-1 Battery remaining capacity detection circuit 5-1 Current supply circuit 6-- Buzzer 7-1 Voltage comparison circuit 8-1 Reference voltage source or higher Agent patent attorney Water supply Kisanbe (and 1 other person)

Claims (1)

[Claims] A power supply circuit includes at least a battery that stores internal power and a remaining capacity detection circuit for the battery, and the power supply circuit does not turn on the power if the remaining capacity of the battery is low when the power switch is turned on, and at the same time A power supply circuit characterized in that it is equipped with means for issuing a warning to a user.