JPS6048025A - Battery check system - Google Patents

Abstract

PURPOSE:To generate a proper warning and monitor the state of a battery efficiently by shortening the time interval of a battery voltage test when the battery voltage drops below a specific level. CONSTITUTION:When battery replacement pulses are outputted from a battery replacement detecting circuit 16 (once an hour), namely, when long-period pulses (b) are outputted from a control circuit 5, the result is held by an FF18. At this time, if a drop in battery voltage is detected, an LCD driver 2 enters warning operation by flashing, etc. At this time, the output of the FF18 is at H, so the 1st and the 2nd AND gates 9 and 11 are switched. Then, the 1st AND gate 9 is opened to input a short-period pulse (a) to an OR gate 10, and battery checking operation is performed at a short period, i.e. once in every 10min. Consequently, if the battery voltage drops below the specific level, warning operation is performed and a battery check is made at the short period, so the check is made accurately and securely.

Description

[Detailed Description of the Invention] (a) Technology Duke The present invention checks for voltage drop due to battery consumption in electronic devices such as cameras that use battery power.
This invention relates to a battery check method for warning and protection.

(b) Prior Art In electronic devices such as cameras, when using a battery power source, normal operation cannot be performed if the battery voltage drops below a predetermined value. Therefore, in this type of equipment,
Battery checks are often performed to detect a drop in battery voltage and prompt the user to replace the battery with a new one, charge a rechargeable battery, or take appropriate protection such as stopping operation.

By the way, for example, even if a battery is not very depleted, if it is placed in an extremely low temperature environment, the output voltage will drop, and the battery will be determined to be defective in a battery check. Even if the battery is returned to a normal temperature state, the normal state does not return to normal until the next battery check operation, and operations such as warnings continue. For this reason, if the battery check period is long, even if the battery is almost normal, once it is determined to be defective, not only will the device become unusable for a while, but the battery will actually run out and measures such as replacing the battery may be taken. It is not possible to quickly determine whether it is necessary or whether the voltage has temporarily decreased due to low temperature or the like, and it becomes impossible to accurately monitor the battery condition.

However, even if the battery is checked too frequently, if the battery is normal, there is no point in using the battery, and it is not a good idea.

(c) Objective An object of the present invention is to provide a battery check method that can efficiently and accurately monitor the battery condition and provide appropriate warning and protection.

(d) Configuration The configuration of the present invention will be described below based on examples.

The embodiment described here is an application of the present invention to a camera data pack, that is, a back cover device for imprinting data such as date, time, etc., and the schematic configuration thereof is shown in FIG.

In FIG. 1, a clock circuit 1 generates time and date data for imprinting. The clock output of this clock circuit 1, ie, date or time data +1 is given to an LCD (liquid crystal) driver 2. LCD driver 2 is LCD 3 for display
And the LCD 4 for imprinting is driven to display the date or time data on both of them. The control circuit 5 switches functions such as date data imprinting, time data imprinting, and no imprinting by external operation, and controls the operation timing of each part according to each function, and is linked with the clock circuit 1. ,. From this control circuit 5, a constant short period, for example 10
A short-period pulse a of about once (1 pulse) is output per minute, a long-period pulse b of about once every hour, for example, and a long-period pulse b of about once every hour is output.
A switching pulse C is output. Furthermore, when the control circuit 51 receives an imprint pulse d to be described later, the lamp 7 as a light source for imprinting is turned on via the lamp driver 6. By lighting the lamp 7, the LCD 4 for imprinting is illuminated, and the display data of LC:D4 for imprinting is imprinted on the photographic film. A pulse-like imprint signal from the camera body (not shown) generated in conjunction with the photographing operation is waveform-shaped by a waveform shaping circuit 8, and is inputted to the clock circuit 1 and the control circuit 5 as an imprint pulse d. Incidentally, the above-mentioned display LCD 3 is used to display the imprint data in the viewfinder of the camera body. The short period pulse a output from the control circuit 5 is input to the OR gate 10 via the first AND gate 9, and the long period pulse b is input to the OR gate 10 via the second AND gate 11.

The OR gate 10 is further inputted with the switching pulse C output from the control circuit 5 and the imprint pulse d output from the waveform shaping circuit 8. A power supply voltage vb from a battery (not shown) is supplied to one path connected to the capacitor 14, and a battery replacement pulse is sent from the terminal of the capacitor 14 via the inverter 15 based on fluctuations in the power supply voltage vb at the time of battery replacement. The battery exchange pulse e from the battery exchange detection circuit 16 that outputs e is also input to the OR gate 10.The output of this OR gate 10 is passed through the inverter 17 to the D-flip-flop 18.
is given as clock power φ. Further, the output of this inverter 17 is input to a battery voltage check circuit 19 to perform a battery check operation. In the battery check circuit 19, the output of the inverter 17 is inputted to the base of the transistor 21 via the resistor 20, and the transistor 21 is turned on. The battery power supply voltage vb is supplied to the parallel circuit with the series circuit of
A voltage obtained by dividing the battery voltage vb by a resistor 22.23,
A comparator 26 compares the reference voltage from the constant voltage diode 25, and when the battery power supply voltage vb decreases, the comparator 26 generates an H (high level) output. The output of this comparator 26 is applied to the D input terminal of the D-flip-flop 18. The imprint pulse d output from the waveform shaping circuit 8 and the output of the OR gate 10 are input to a dummy load circuit 27 for applying a load corresponding to data imprinting to the battery during battery checking other than during data imprinting. That is, the imprint pulse d and the output of the OR gate 10 are applied to the Nant gate 28, and the logical negation value of the imprint pulse d and the output of the OR gate 1 are applied.
A NAND output with an output value of 0 is input to the base of the transistor 30 via the resistor 29, and the transistor 30 is turned on only when the output of the imprint pulse d is L (low level) and the output of the OR gate IO is H. . Therefore, the transistor 30 operates to connect the dummy load 31 to the battery when it is on, and to disconnect the dummy load 31 from the battery when it is off. D-flip-flop 18
The output is given to the LCD driver 2 to perform a warning operation such as flashing the display on the display LCD 3 only when H (high level), and is also given to the first AND gate 9 to open the gate only when H (high level). The signal is applied to the second AND gate 11 via the inverter 32 and closes the gate only when the signal is H.

In such a configuration, the battery check circuit 19 operates to perform a battery check when the OR gates 1-0 output H under a load condition of 40 mA-50 ms, for example.
This battery check circuit 19 operates when the switching pulse C from the control circuit 5 is output, that is, when the function is switched, and when the imprint pulse d from the waveform shaping circuit 8 is output.
, that is, when data is imprinted, and when a battery replacement pulse is output from the battery replacement detection circuit 16, that is, when replacing the battery, the output of the D-flip-flop 18 becomes L during normal operation. Since the first AND gate 9 is closed and the second AND gate 11 is open, when the long period pulse b is output from the control circuit 5, that is, when the second AND gate 11 is
It is done once an hour. This result is held by the D-flip-flop 18, and when a decrease in battery voltage is detected, the LCD driver 2 performs a warning operation such as a blinking operation. At the same time, since the output of the D-flip-flop 18 is H, the first and second AND gates 9 and 11 are switched, and this time, the first AND gate 9 is opened and the short period pulse a is sent to the OR gate. 10 and 1 every 10 minutes
The battery check operation will be performed in a short period of 30 seconds.

In this way, when the battery voltage falls below a predetermined voltage, a warning operation is performed and a battery check is performed in short cycles, so battery checks can be performed accurately and reliably, and when the battery voltage temporarily drops due to a drop in temperature, etc. However, if the temperature returns to normal and the battery voltage becomes normal, this is immediately detected and normal operation returns. Therefore, an extremely accurate battery check operation is possible.

It should be noted that the present invention is not limited to the embodiments described above, and can be implemented with various modifications without changing the gist thereof.

For example, FIG. 2 shows another embodiment of the invention.
In this case, the battery voltage at which the warning operation starts is different from the battery voltage at which the battery cycle is shortened, so that as the battery voltage decreases, the battery cycle is first shortened and then the warning is issued.

In FIG. 2, a window comparator is connected between two voltages sandwiching the operating voltage of the comparator 26 for starting a warning operation by blinking the display on the LCD 3, and the upper limit is at point A in the figure. ,37
, diode 1-'38.39, and this window comparator is added to the battery check circuit 19 shown in FIG. A second D-flip-flop 40 is provided which operates with the same clock input (φ) as the D-flip-flop 18 and whose D input terminal receives the signal at the output point A of the window comparator. The output of the D-flip-flop 40 is connected to the first AND gate 9 and the inverter 3.
I try to give it to 2. Therefore, when the battery voltage decreases, the window comparator operates at the first level (this is called the set level), its output is latched by the D-flip-flop 40, and the battery check interval is switched to a short period. The comparator 26 operates when the battery voltage drops to a second level (this is the verification level), and its output is sent to the D-flip-flop 18.
is latched and the display on the LCD 3 is switched to a blinking display.

In this case, since the battery check interval is shortened before the warning occurs, there is an advantage that the warning operation can be made more accurate.

Further, the battery check interval may be shortened by using only the comparator 36 without using the window comparator.

Of course, the protection operation may be added to the warning operation, or the level may be determined using other configurations, or the present invention may be applied to electronic devices other than data packs.

(e) Effects As described in detail above, according to the present invention, it is possible to provide a battery check method that can efficiently and accurately monitor the battery condition and provide appropriate warnings and protection.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the structure of one embodiment of the invention, and FIG. 2 is a block diagram showing the structure of another embodiment of the invention. 1... Clock circuit, 2. Old... LCD driver,
3...For display, CD, 4...LCD for imprinting, 5...Control circuit, 6...Lamp driver, 7... ...Lamp, 8...Waveform shaping circuit,
9.11...AND gate, 10...OR gate, 16...Battery replacement detection circuit, 18, '40
・・・・・・D-Flip-flop 8.19.19'・
...Battery check circuit, 27...Dummy load circuit, 32...Inverter.

Claims (3)

[Claims] (1) In a battery check method that automatically verifies the battery voltage at a predetermined timing and performs at least one of a warning action and a protective action when the battery voltage falls below a preset verification level, the battery voltage is set. A battery check method characterized in that the time interval of the battery voltage verification is shortened when the voltage falls below the level. (2) The battery check method according to claim 1, wherein the set level is equal to the test level. (3) The battery check method according to claim 1, wherein the set level is higher than the certification level.