JPS60243579A - Apparatus for displaying consumption of battery - Google Patents

Abstract

PURPOSE:To prevent the erroneous display of battery consumption even if the variation in the voltage of a battery is generated, by forming a voltage detection part by the transistor circuit in IC and connecting a display element for performing the display of an alarm, when the battery is consumed, to IC. CONSTITUTION:A secondary battery 4 is connected to a secondary coil 3 through a rectifier 5 and resistors 6, 7 are connected to the battery 4 in parallel to constitute a voltage dividing circuit. A one-chip IC8 detects the voltage at the voltage dividing point 9 of a voltage dividing circuit. Further, a series circuit, which consists of a light emitting diode LED11 for displaying the consumption of a battery and the resistor 12 and condenser 13 of a CR time constant circuit for determining the ON-and-OFF operation time of said diode LED11, is connected to said voltage dividing circuit in parallel while a voltage detection part is constituted of a transistor and a resistor. When VTH is 1 or less, a Hi-signal is issued from said voltage detection part and, when VTH is 2 or more, tolerance is provided so as to output a Lo-signal and the unstability or erroneous operation of LED11 can be prevented.

Description

[Detailed Description of the Invention] (A J Industrial Field of Application) The present invention detects and displays a warning when the battery is exhausted in an electrical device that drives a load such as a motor using a power source battery such as a manganese dry battery or a NiCd battery. The present invention relates to a battery consumption display device.

(b) Prior art As the electrical equipment covered by the present invention, power batteries were used in the 1970s.
Publication No. 9-201 discloses a technology that warns the state of power consumption of an electric razor by lighting an indicator lamp. However, a positive feedback circuit is not connected to the transistor circuit in such a checker. Therefore, no hysteresis characteristic is observed in the voltage detection value.In the case where a motor is connected to a battery in a circuit, the battery voltage ripples due to the back electromotive force caused by the rotation of the motor.

Since the checker detects the voltage that fluctuates due to this ripple, the problem is that the indicator lamp lights up even though the battery voltage is at a sufficiently high value, giving a warning when the battery is low. be.

In addition, especially in the case of electric razors, it is desirable to display a battery warning display while the battery capacity is still available for 2 to 5 uses, assuming that each use takes about 6 minutes, but the ambient temperature of the battery There is a problem in that early consumption is displayed even though there is still a sufficient amount remaining. The above publication does not compensate for such problems.

(c) Purpose of the Invention The present invention has been made in view of the problems of the prior art as described above, and it is possible to prevent false indication of battery consumption even if the battery voltage fluctuates due to driving of a load connected to the battery. It is an object of the present invention to provide a battery consumption display device having a voltage compensation function with respect to battery ambient temperature without causing any damage to the battery.

B) Structure of the Invention A voltage detecting section for detecting a voltage drop in a power supply battery is formed by a transistor circuit formed in an IC, and a display element displays a warning when the battery is exhausted based on a detection signal of the voltage detecting section. is connected to the IC,
The present invention is characterized in that a positive feedback circuit is connected to the transistor circuit to impart hysteresis characteristics to the detection signal of the voltage detection section.

(e) Embodiment FIG. 1 shows a basic circuit diagram of an embodiment of the battery consumption device of the present invention.

(1) is a step-down transformer formed by a primary coil (2) connected to a commercial AC power supply and a secondary coil (3) electromagnetically coupled to the secondary coil; (4) is a step-down transformer formed by the hand-blown coil (
A quaternary battery B1, +61171, such as a J-cadmium battery, is connected to the battery (4) through a rectifier (5), and resistors R1, R2, (8) are connected in parallel to the battery (4) and constitute a voltage dividing circuit.
) is the first channel that detects the voltage at the voltage dividing point (9) of the voltage dividing circuit.
This is Hupue C. This IC+81 has terminals ■～■(■,
(2) (not shown), and the voltage dividing point (9) is connected to the terminal (2). 01 is an adjustment resistor VR connected between terminals 0 and 0 of the IC (8). The voltage dividing circuit includes a light emitting diode LED (Ill) for indicating battery consumption and O determining the blinking operation time of the light emitting diode (Ill).
A series circuit consisting of a resistor R3 (121) and a capacitor C1 (1:1) constituting the R time constant circuit is connected in parallel;
A capacitor 02061 for ripple absorption is connected via a connection point 09 with Q2.

αη is connected to the battery B 1 + via the starting switch Sa seconds
41, and the switch SQ is inserted between the battery B 1141 and the resistor R2+71. The ground terminal ■ of the IC (8) is also connected to the battery B 1 (4
Connected to 1. Terminals ① and ② of the above 1-pull 8) are connected to each other, and the above-mentioned resistor R3 (12 and capacitor 0111:
It is connected to connection point 09 with l.

FIG. 2 is a circuit diagram showing the contents of the Cf81 in detail. ■ is a voltage detection unit connected to the terminals ■, ■, ■, and The terminal of the oscillating section is connected to the terminal (2).

@ is a transistor Q6 whose base is connected to the terminal O of the oscillation section, and whose collector is connected to the terminal ■, and whose emitter is connected to the terminal ■. Inverter INV is the output legitimate child of lightning pressure supply section (A).
(Transistor Q whose base is connected through 241
7, its collector is connected to the terminal (2), and the emitter is connected to the terminal (2).

FIG. 3 is a circuit diagram showing details of the voltage detecting section (2).

As is clear from the figure, the voltage detection section includes five transistors Q1 to Q, 5 (2! to),
Consists of 弼, (7), and (to). Transistor Q1
(251 has its base connected to the terminal ■ through the terminal ■ and the resistor r1ω, and its emitter and lid are connected to the terminal ■. The base of the transistor Q2α) is connected to the collector of the transistor Q, I Cal and Resistance r2 (
It is connected to the front ε terminal (2) via lη, the emitter is connected to the terminal (2), and the collector is connected to the terminal (2) via a resistor r3 (A). Transistor Q3
The base of @ is connected to the terminal ■ via the collector of the transistor Q, 2■ and the resistor r3g4, the emitter is connected to the terminal ■, and the collector is connected to the resistor r4.
((connected to the terminal ■ through 3 and resistor r7 (to)
is connected to the base of the transistor Q2@ to form a positive feedback circuit. The base of the transistor Q4@, the collector of the transistor Q3@, and the resistor r4 (
The emitter is connected to the terminal (2) through a resistor r5 (to), and the collector is connected to the terminal (2) through a resistor r5 (to). Transistor Q5
The base of the transistor Q4■ is connected to the terminal ■ via the collector of the transistor Q4■ and the resistor r5 (to), the emitter is connected to the terminal ■, and the collector is connected to the terminal ■ via the resistor r6Gl19. and is connected to the output terminal (2). If battery B 1141 has sufficient capacity and the battery voltage is high, the voltage input to terminal ■ of IC (81) is high, and transistors Q, 1 (25, Q3
@, Q, 5Ci! iI is on, and transistors Q2 (a) and Q4@ are off. The transistor Q5 (21
is on, so LO is output from the output terminal ■ of the voltage detection section ■.
The double signal is output and enters this LO double signal oscillation section (211). Therefore, this oscillation section 211 does not oscillate.

On the other hand, the LO signal is converted into an H1 signal by the inverter INV-, and this H1 signal causes the transistor Q7 to
(to) is turned on. Therefore, the light emitting diode LEDQI
A current flows through I→resistor R3Q2→transistor Q7, but since the resistance value of resistor ftao is large, the light emitting diode LED (Ill) does not light up.

As the use of the battery B 1 f41 progresses and the battery voltage decreases, the voltage input to the terminal ■ becomes low and the transistors Q, 1 (5), Q3 @, Q, and flll are turned off. Transistors Q, 2 (261, Q, 4) are turned on. However, even at this low voltage value, motor MQ
71 can be driven for a short time. That is, when the transistors Q and 5 (2!l) are turned off, a Hi-fold signal is output from the output terminal (2) of the voltage detection section (2), so the transistor Q7 (to) is turned off, and the light emitting diode (L) is turned off.
EDQ11 → Resistor R3 (12 → Capacitor C1 (13), and current flows to charge the capacitor 01α3. When the capacitor 01 (131) is fully charged, it has a high voltage. IC
The H1 signal is input through the terminal ■. −＾ From the output terminal ■ of the voltage detection section ■ to the oscillation section (21
Since the 1KH'l- signal is input, the oscillator (2) outputs the H1 signal from the terminal P, turning on the transistor Q6. Therefore, a current flows from the light emitting diode LED σ1) to the transistor Q and 6r22, and the light emitting diode L ED till lights up. Said capacitor C10
31 is also a resistor R3 (12→transistor Q6) after full charge.
■Discharge through. While this capacitor 0113) is discharging, a signal is input to the input terminal of the oscillation unit 0113).

Since the oscillations of the LO and the mother oscillator section stop, the transistors Q and 6122 are turned off, and the front ξ light emitting diode LED III is turned off. Thereafter, as the capacitor ClO3 is charged and discharged, the light emitting diode LE]]111 turns on and off repeatedly, so the light emitting diode LED
111 flashes and 1. Displays a warning that the voltage of battery B 1 f4+ has decreased.

As shown in FIG. 4, the battery voltage when there is no load such as a motor that generates a back electromotive force draws a stable curve (1) over time as the current usage progresses. By adjusting the resistance value of regulating resistor VRQ (l), the battery voltage is
If the H1 signal is outputted from the voltage detection section (2) to the oscillation section (incorporated) when the voltage reaches h, the above-described blinking of the light emitting diode LKDQI can be performed accurately. This voltage vth is the voltage when there is capacity to drive the motor MQη for about 10 minutes remaining. However, when the motor M (171) is connected as in the present invention, the switch S
[When 181 is turned on and motor M (171 is driven) (time toN in FIG. 5), the voltage applied to the terminal ■ of the IC+s+ undergoes ripple fluctuations as shown in FIG. 5. If the voltage of the IC (8) If the detection unit @ does not have hysteresis characteristics, the voltage detection unit ω will also detect a temporary drop in the battery voltage due to this ripple fluctuation, and therefore the light emitting diode LEED (manufactured by LEED) will still detect the battery voltage at a predetermined level. It blinks even though the value has not been reached.For this reason, in the present invention, the transistors Q and l constituting the voltage detection section are
A positive feedback circuit is provided between the base of Q3 and the collector of Q3 via a resistor r7 to provide hysteresis characteristics. With this configuration, the detected voltage has a range so that when the input voltage of the terminal (2) is less than VTR1 in FIG. This makes it possible to prevent unstable operation and malfunction of the light emitting diode LEDu11.

The transistors Q, 1-Q, 7(c) to (21+22
(to) is not an independent transistor, but the above-mentioned process C (8
), its characteristics take temperature dependence into account from the beginning, and therefore changes in battery voltage due to ambient temperature of battery B 1141 are automatically compensated for.

Here, it is assumed that the battery consumption display device of this embodiment is incorporated into an electric oven. In the case of an electric shaver, the voltage when the battery capacity reaches the capacity that can be used for 2 to 3 times, that is, the capacity that can drive the motor for about 10 minutes (voltage at time tR in the battery voltage characteristic diagram in Figure 6) It is desirable to detect this and display a warning about battery depletion. However, the battery voltage characteristics fluctuate as the ambient temperature of the battery changes (approximately 1 m'V/l'' for Tsukado batteries), and Figure 6 clearly shows this situation, with the characteristic curve at ambient temperature 01 +11
．． The characteristic curve at 20° C. (mark) and the characteristic curve at 40° C. (W) draw different curves.

Therefore, the voltages at the time tR are 0, 2, and 2, respectively.
40, and since there exists a relationship such as VO x v20 x v40, especially when the ambient temperature of battery B 1 + 41 is low, the light emitting diode L''El:Dtll will blink even though there is still sufficient remaining capacity. In order to compensate for this, the voltage of the transistor Q1 (2) of the voltage detection section (2) has a positive temperature characteristic as shown in FIG. When the battery voltage is low, the setting is made so that the H1 signal is output from the output terminal (■) of the voltage detection section (■) only when the battery voltage has significantly decreased.By doing this, the light emitting diode LEDQ]
3 can be delayed in time, and a battery exhaustion warning can be displayed when the remaining capacity of battery B 1 +41 becomes low. In this way, since the voltage C(8) itself has temperature dependence, temperature compensation of the battery voltage is achieved by using the voltage C+81. Also, the slope of the characteristic curve in Fig. 7 is that the transistor Q, 1-
Q.

It can be freely adjusted when forming resistors r1 to r7 (to) and the like.

Furthermore, by using IC+81, the light emitting diode L E D Qll due to the ripple fluctuation of the motor Mα9
In order to completely eliminate the ripple fluctuations, a capacitor C2Q61 is inserted in this embodiment to absorb the voltage ripple fluctuations.

Figures 8 and 9 are voltage waveform diagrams at the connection points, where Figure 8 is the one using the voltage detection section ■ having hysteresis characteristics in this embodiment, and Figure 9 is the conventional one without hysteresis characteristics. It is.

In FIG. 9, the blinking start time is earlier than in FIG. 8, and the blinking is unstable, resulting in flickering parts gt)@, but in FIG. 8, the blinking timing is accurate and the blinking is stable.

FIG. 10 shows an implementation circuit of a battery consumption display device when a battery B2 wire having a larger capacity than the battery B 1 +41 in FIG. 1 is used. As is clear from the figure, the resistor R4Q4 connected in parallel to the light emitting diode LED (111)
1, and a resistor R6α→ is inserted between the battery B2 (to) and the connection point (6) between the resistor R5- and the light emitting diode LEDGI). In this way, the same battery consumption display device can be used even if the capacity of the battery to be tested changes.

(f) Effects of the Invention As described above, the present invention includes forming a voltage detection section for detecting a voltage drop in a power source battery using a transistor circuit formed in an IC, and detecting a voltage drop based on a detection signal of the voltage detection section. A display element for displaying a warning when the battery is exhausted is connected to the circuit C, and a positive feedback circuit is connected to the transistor circuit to impart hysteresis characteristics to the detection signal of the voltage detection section. The battery voltage due to the load connected to the battery is
It is possible to prevent malfunction of the display element even if there is a sample fluctuation, and by configuring the voltage detection section with a component C, temperature dependence can be taken into account in the detected value, and the battery voltage depending on the ambient temperature of the battery can be This has the effect of automatically performing temperature compensation.

Moreover, since the battery consumption display device of the present invention can be configured with substantially the same circuit even if the battery capacity changes, there is also the effect of improving the degree of freedom in the devices that can be used.

[Brief explanation of the drawing]

Fig. 1g1 is an implementation circuit diagram of the battery consumption display device of the present invention, Fig. 2 is an internal configuration circuit diagram of part C in Fig. 1, Fig. 6 is an internal configuration circuit diagram of the voltage detection section in Fig. 2, and Fig. 4 The figure is a battery voltage characteristic diagram when no load is applied, and Figure 5 is a battery voltage characteristic diagram when load is activated.
Figure 6 is a temperature characteristic diagram of the battery voltage, Figure 7 is a temperature characteristic diagram of the voltage detection section, Figure 8 is a voltage characteristic diagram of the display element with hysteresis characteristic, and Figure 9 is a diagram of the voltage characteristic of the display element without hysteresis characteristic. A voltage characteristic diagram of the display element, and FIG. 10 is another implementation circuit diagram. (4) (To)...Battery, ■...Voltage detection section, (8)
...IC, (@fi (c) (a) @@□□□...transistor, (111...display element, (2)...positive feedback circuit. Fig. 5 Fig. 6

Claims (1)

[Claims] (1) The voltage detection part that detects the voltage drop of the power supply battery is an IC.
A display element is formed by a transistor circuit formed in the circuit C and is connected to the circuit C to display a warning when the battery is exhausted based on the detection signal of the voltage detection section, and a positive feedback is provided to the transistor circuit. A battery consumption display device characterized in that a hysteresis characteristic is imparted to the detection signal of the voltage detection section by connecting a circuit.