JPS62126833A - Charge indicating circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a charge display circuit that displays the degree of charge of a storage battery included in a rechargeable electric razor or the like.

[Background technology]

For devices such as rechargeable electric razors (hereinafter referred to as rechargeable devices), charging of the storage battery may be stopped due to, for example, being accidentally unplugged from the outlet during charging, even though the storage battery has not yet reached 100% charge. It may happen that you do.

If this is repeated, the N battery will deteriorate quickly, shortening the life of the storage battery, and if equipped with a remaining capacity display, the remaining capacity may not be displayed accurately.

To prevent this, rechargeable devices have conventionally been equipped with a charge display circuit that displays the degree of charge of the storage battery. As shown in Figure 7, one of the conventional charging display circuits used in rechargeable devices is to display a red LED ( There was a device that turned on a light emitting diode) and after reaching 100% (area B in the figure), turned on a green LED to indicate the completion of charging of the storage battery, but this one If you don't always look at the display, you won't know when the charging level reaches 100%, and even if you constantly look at the display, you won't even be able to predict when the charging level will reach 100%. Even if you wanted to use a rechargeable device immediately after reaching the limit, you could not use it, which was inconvenient. In addition, when the degree of charge reaches 100%, the charging current decreases from 1 to 1□, but in order to prevent insufficient capacity of the storage battery due to variations in charging capacity and to activate the storage battery, the degree of charge is reduced to 100%. Even after reaching the limit, it is necessary to continue to flow the amount of It, although it is a small amount, to continue charging the storage battery. Therefore, if charging is not stopped by unplugging the rechargeable device from the outlet, the storage battery becomes overcrowded. Moreover, it is a rechargeable device with a remaining capacity display, and the remaining capacity display method is that the storage battery is rated at 100%.
The battery is set to have a charged capacity and the amount used is subtracted (methods that use this method have the problem of errors in the remaining capacity display).

Apart from the above, as a conventional charging display circuit, the 8th
As shown in the figure, just before the charging level reaches 100%,
That is, until the charging degree reaches approximately 80% (in the figure, C
area), turn on the red LED, and after the charging degree reaches approximately 80% (area D in the figure), change the charging current from ■ to ■4.
There are some devices that display charging completion by lowering the charge to 100% and changing the red LED and green LED to flash alternately. However, this device does not display when the degree of charge has reached 100%, so it has the disadvantage that it is unclear whether the degree of charge has reached 100%.

[Purpose of the invention]

In view of the above circumstances, the present invention is capable of predicting the time when the degree of charge of a storage battery reaches 100%, and when applied to a rechargeable device equipped with a remaining capacity display, the remaining capacity display is more accurate. DISCLOSURE OF THE INVENTION In order to achieve the above object, the present invention is designed to display the charging degree of a storage battery while the storage battery is being charged. In the charging display circuit, the first region is from the start of charging to the designed charging degree before the charging degree of the storage battery reaches 100%, and after the storage battery reaches the designed charging degree. By design, the second area until the charging level reaches 100% and the third area after the storage battery reaches the designed charging level of 100% are designed to display different images, and the second area The gist of the present invention is a charge display circuit characterized in that it displays differently depending on the degree of charge of a storage battery even within the range of .

Hereinafter, an example in which one embodiment of the invention is applied to a rechargeable electric razor will be explained in detail with reference to the accompanying drawings.

As shown in FIGS. 4 and 5, this rechargeable electric razor includes a storage battery, a charging circuit, a charge display circuit 1, and a remaining capacity display 2. The charging display circuit 1 consists of a ^/D converter, an arithmetic control circuit, and a display circuit, and inputs the storage battery voltage of the storage battery to the arithmetic control circuit through the ^/D converter, and displays the red LED (first lamp) 3 of the display circuit. Alternatively, the green LED (second lamp) 4 is driven.

The red LED 3 and the green LED 4 are arranged so that when the red LED 3 is turned on, the green LED 4 is turned off, and when the green LED 4 is turned on, the red LED 3 is turned off.

The operation of this charging display circuit l is shown in a flowchart as follows:
This can be seen in Figure 3. First, let's explain the symbols. ■
is the storage battery voltage, and VLh is the designed M battery voltage corresponding to the designed charging degree of the storage battery. The period length 'F is the time when the green LED lights up and then the red LED lights up.
This is the time from when the light turns on until it turns off. to
is the design time from when the charging degree of the storage battery (in this example, determined by the storage battery voltage) reaches the designed charging degree until it reaches the designed charging degree of 100%, Set at about 8 degrees. t is the elapsed time counted by a timer after reaching the designed charging degree. n is a constant when varying the blinking ratio of the red LED and the green LED (the ratio of the lighting time length within one cycle) in n steps, and is set in the range l<n≦to/T. TG indicates one lighting time of the green LED.

Next, a flowchart will be explained along with a graph (FIG. 2) showing the storage battery voltage or charging current with respect to charging time.

The start starts when a charging start signal enters the charging circuit in FIG. First, only the red l-ED continues to light up. Next, the storage battery voltage ■ is detected and compared with ■. When ■≧■, set the cycle length T,
The timer starts counting. t≦(1/n)
If to, green leaves EDGT x (1/n)
After lighting, the red LED is lit until the period T has elapsed. (1/
n) to<t≦(2/n)t.

If so, the green LED is turned on for Tx (2/n), and then the red LED is turned on until the period T has elapsed. Furthermore, (2/n
) to<t≦(3/n) If to, the lighting time T6 of the green LED becomes Tx (3/n). In this way, t is 1. As it approaches, the lighting time of the green LED within one cycle becomes longer than the lighting time of the red LED (Repeat this 0 times, and when t≧L), only the green LED continues to be lit, and charging Indicates completion.If t≧t0, that is, if the degree of charge of the storage battery reaches 100% as designed, the arithmetic control circuit issues a signal to the charging circuit to reduce the charging current from I to I6. The display modes of the red LED 3 and green LED 4 described above are shown in FIG. 1.

Here, until the storage battery voltage becomes ■ becomes low (from the start of charging to the designed charging degree before the charging degree of the storage battery reaches 100% according to the design), the period t0 (when the storage battery is By design, after reaching the charging degree specified above,
(until the degree of charge reaches 0%) is the second region, t≧0
If the third region is after the battery has reached 100% charge by design, then in the first region only the red LED remains lit, and in the second region Different displays are performed in each area, with red LEDs and green LEDs flashing alternately in the third area, and only the green LED remaining lit in the third area. Moreover, within the second area, with a blinking cycle of a constant length T,
Green L for red LED lighting time within one cycle
By design, the percentage of the ED lighting time is 10 when the storage battery is charged.
It gets closer to 0% (and gets bigger as it gets closer to 0%). In other words, when the green LED starts to light up for a long time, the battery charge level is 10%.
It is approaching 0%. This charging main display circuit is configured as described above, so if you look at the LED, you can see that the charging level of the storage battery is low by design.

It is possible to predict the time when the percentage will be reached.

Next, another example will be shown. FIG. 6 is a waveform diagram showing the display mode of this embodiment. As shown in the figure, in this example, the red L within one period within the second region
The ratio of the green lighting time to the ED lighting time is kept constant, and the cycle length is shortened as the charging degree of the storage battery approaches 100% in design. Even in this case, just by looking at the LED, it is possible to predict the time when the charging level of the storage battery will reach 100% according to the design.

The charging display circuit according to the present invention is not limited to the above embodiment. It goes without saying that the device to which the charging display circuit according to the present invention is applied is not limited to a rechargeable electric razor, but can also be applied to other rechargeable devices.

〔Effect of the invention〕

Since the charging JR display circuit according to the present invention is configured as described above, it is possible to predict the time when the degree of charge of the storage battery reaches 100%. Therefore, if a rechargeable device is equipped with this, the storage battery will reach 100% charge and be ready for use. Moreover, since charging can be stopped immediately after the degree of charge of the storage battery reaches 100%, overcapacity of the storage battery can be prevented. In particular, if applied to a rechargeable device equipped with a remaining capacity display, the remaining capacity display can be made more accurate.

[Brief explanation of drawings]

Fig. 1 is a waveform diagram showing the display mode of an embodiment of the charging display circuit according to the present invention, Fig. 2 is a graph showing the relationship between the storage battery voltage or charging current with respect to the charging time of the same, and Fig. 3 is the same as the above. Fig. 4 is a plan view of a rechargeable electric razor to which this embodiment is applied, Fig. 5 is its circuit diagram, and Fig. 6 is a waveform showing the display mode of another embodiment. 7 and 8 are graphs showing the relationship between charging time and storage battery voltage or charging current in conventional charging display circuits, respectively. 3... Red LED (first lamp) 4... Green LED (second lamp) Agent Takehiko Matsumoto Figure 1 Figure 2 Figure 3 Figure 5 Figure 6

Claims (6)

[Claims] (1) In a charging display circuit that is designed to display the degree of charge of a storage battery while it is being charged, from the start of charging until the degree of charge determined by design before the degree of charge of the storage battery reaches 100%. 100% by design after the first region of
The second area until the charging level reaches 100% and the third area after the storage battery reaches the 100% charging level are displayed differently, and even within the second area. A charge display circuit characterized in that a different display is displayed depending on the degree of charge of a storage battery. (2) The charging display circuit according to claim 1, wherein the charging display circuit emits a signal that reduces the charging current in the third region. (3) The boundary between the first area and the second area is determined based on the storage battery voltage, and the boundary between the second area and the third area is determined based on the storage battery voltage.
The charging display according to claim 1 or 2, wherein the boundary between the first area and the second area is determined based on the elapse of a certain period of time from the boundary between the first area and the second area. circuit. (4) Performing different displays in the first, second, and third areas means that only the first lamp is lit in the first area, and the second lamp and the first lamp are lit in the second area. 4. The charging display circuit according to claim 1, wherein the charging display circuit is made by alternately and repeatedly blinking and lighting only the second lamp in the third region. (5) Different displays may be displayed depending on the degree of charge of the storage battery within the second area. Claim 4 is achieved by increasing the ratio of the lighting time of the second lamp to the lighting time of the first lamp within one cycle as the degree of charge approaches 100% without changing the degree of charge. charging display circuit. (6) Different displays may be displayed in the second area depending on the degree of charge of the storage battery. Claim 4 is achieved by shortening the cycle length as the degree of charge approaches 100% without changing the ratio of the lighting time of the second lamp to the lighting time of the first lamp. charging display circuit.