JPH0437661B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a charging device for storage batteries for various electrical appliances such as electric shavers, and is particularly applicable to charging devices equipped with a plurality of storage batteries such as a main storage battery and a sub-storage battery. , which allows each storage battery to be fully charged almost simultaneously.

[Conventional technology]

The discharge characteristics of storage batteries for electrical equipment are preferably such that they can maintain a predetermined battery voltage for as long as possible until the end of discharge, and for example, nickel-cadmium storage batteries are often used. However, a storage battery having such discharge characteristics has a drawback that when the discharge nears completion during use, the battery voltage drops rapidly, causing the device to suddenly stop operating and making the device unusable thereafter. For this reason, some devices are equipped with a backup auxiliary storage battery in addition to the main storage battery, and when the main storage battery finishes discharging during use, the auxiliary storage battery is used by switching a switch.

[Problem that the invention seeks to solve]

However, due to its nature, the rated capacity of the secondary storage battery is usually much smaller than that of the main storage battery, but when primary and secondary storage batteries with large differences in rated capacity are charged at the same time, the secondary storage battery with a smaller rated capacity The storage battery completes charging earlier than the main storage battery, which has a larger rated capacity, and the main storage battery continues to be charged even after the auxiliary storage battery is fully charged, resulting in the auxiliary storage battery being overcharged.

In particular, this type of storage battery generally has the characteristic that the voltage rises rapidly before charging, and due to this characteristic of the main storage battery, an excessive voltage is applied to the secondary storage battery that has completed charging first, causing the secondary storage battery to deteriorate. Become.

[Means for solving problems]

Therefore, the present invention has been made for the purpose of providing a device that eliminates the drawbacks of such a charging device equipped with a plurality of storage batteries, and includes a rectifying section D ₁ that rectifies the AC power source 1, and a rectifying section D 1 that rectifies the AC power source ₁ . The main storage battery B ₁ with a large capacity rating and the auxiliary storage battery B ₂ with a small capacity rating are supplied with a sinusoidal charging current, and the peak value of each cycle of the sinusoidal waveform of the charging current is detected, and the A switching circuit section 4 that switches charging current supply to each of the storage batteries B ₁ and B ₂
The switching circuit unit 4 detects that the peak value exceeds a predetermined height so that the charging time of the auxiliary storage battery _B2 becomes shorter than the charging time of the main storage battery _B1 . This is done by stopping the supply to the sub-storage battery _B2 , thereby allowing each storage battery to be fully charged almost simultaneously.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an electric circuit of a charging device, and 1 is an AC power source, to which the primary side of a step-down transformer 2 is connected. A rectifier D ₁ consisting of a rectifier diode is connected to the secondary side of the step-down transformer 2, and a small-capacity sub-storage battery with a small rated capacity is connected to the secondary side of the step-down transformer 2.
B ₂ and a switching circuit 4 consisting of a thyristor 3 and gate bias resistances R ₁ and R ₂ of the thyristor 3 are connected in parallel, and an auxiliary storage battery B ₂
A large-capacity main storage battery _B1 with a large rated capacity is connected in series with the switching circuit 4.
D ₂ is a diode for preventing discharge of sub-storage battery B ₂ , R ₃ ,
R ₄ is a charging current control resistor connected to the sub-storage battery B ₂ and the thyristor 3.

5 is a sliding switch button connected to the drive motor M of the device, and each storage battery
The contacts 6 ₁ , 6 ₂ and contacts 6 ₂ , 6 ₃ of B ₁ and B ₂ are selectively connected to each other. That is, under normal conditions, the switch button 5 is connected to the contacts 6 ₁ and 6 ₂ and the motor M is driven by the main storage battery B _{1 .}
When the discharge of the motor M is finished and the motor M cannot be driven, slide the switch button 5 to close the contact.
6 ₂ and 6 ₃ , and the motor M is driven by the auxiliary storage battery B ₂ .

This device consists of the above configuration, and then the second
The operation will be explained with reference to the figures.

The AC power supply voltage is stepped down by the step-down transformer 2, and further rectified by the rectifier _D1 , so that the current waveform on the cathode side of the rectifier _D1 becomes a half-wave sine waveform as shown in FIG.

Here, at the beginning of each sine waveform, charging current ₁ flows through the charging current supply path consisting of resistor R ₃ , diode D ₂ , auxiliary storage battery B ₂ and main storage battery B ₁ and passes through both storage batteries.
Charge B ₁ and B ₂ together.

At this point, the bias resistors R ₁ and R ₂ have
The voltage drop due to the charging current ₁ of the resistor R ₃ and the diode D ₂ is added to the sum voltage of the terminal voltage of the auxiliary storage battery B _2. In this case, the voltage of the auxiliary storage current B ₂ does not change significantly, and the voltage drop mentioned above is Therefore, at both ends of the bias resistors R ₁ and R ₂ ,
A change in charging current ₁ of sub-storage battery B ₂ appears.

Therefore, when this change is small, the thyristor 3 is in the cut-off state, but the charging current ₁
increases according to the sinusoidal waveform, and the bias resistance R ₁ , R ₂
When the wave height value appearing at both ends of is high, thyristor 3
turns on and conducts, and the charging current ₂ begins to flow through the thyristor 3 to the main storage battery _B1 . Here, the combined resistance of the loop consisting of resistor R ₃ , diode D ₂ , and sub-storage battery B ₂ becomes much larger than the combined resistance of the loop consisting of resistor R ₄ and thyristor 3, and the charging current supply path is switched. The charging current ₁ to the auxiliary storage battery B ₂ is stopped, and only the main storage battery B ₁ is charged by the current ₂ flowing through the thyristor 3. In Figure 2, t ₁ is the time when thyristor 3 is in a cut-off state and both main and sub storage batteries B ₁ and B ₂ are charged, and t ₂ is a time when thyristor 3 is in a conductive state and only main storage battery B ₁ is charged. It's time,
The amount of charge in the main storage battery B ₁ is proportional to the total area of the half-wave sine waveform, and the amount of charge in the auxiliary storage battery B ₂ is proportional to the area of the shaded portion. Note that the dotted line in FIG. 2 indicates the voltage waveform of the AC power source. In this way, the half-wave sine current rectified by the rectifier D ₁ is divided by the switching circuit 4 so that the charging time of the auxiliary storage battery B ₂ is shorter than the charging time of the main storage battery B ₁ , and each storage battery B ₁ ,
By supplying power according to the capacity of B ₂ , both storage batteries B ₁ and B ₂ with different rated capacities can be fully charged almost simultaneously.

FIG. 3 shows another embodiment of the present invention, in which a transistor Q is provided in place of the thyristor 3, and a switching circuit 7 is constituted by bias resistors R ₅ and R ₆ . Therefore, while the voltage across the bias resistors R ₅ and R ₆ , that is, the voltage drop caused by the charging current ' ₁ flowing in the supply path on the side of the sub-storage battery _B2 , is small (see Figure 4, _t1 ), the transistor Q is in the cut-off state. and the current′ ₁
flows from sub-storage battery B ₂ to main storage battery B ₁ and connects both storage batteries.
Both B ₁ and B ₂ are charged, but the bias resistor R ₅ ,
When the voltage across _R6 increases, transistor Q becomes conductive. Then, the supply path to the auxiliary storage battery B ₂ is switched, the current in this loop 1 is stopped, and only the main storage battery B ₁ is charged by the current I' ₂ flowing through the transistor Q. Next, when the sinusoidal waveform decreases and the voltage across bias resistors R ₅ and R ₆ becomes smaller,
The transistor Q becomes cut-off again, and both the main and sub storage batteries B ₁ and B ₂ are charged by the charging current ' ₁ (see t' ₁ in FIG. 4).

〔effect〕

As explained above, the charging device according to the present invention has
A rectifier D ₁ that rectifies the AC power supply 1 and this rectifier
The main storage battery B ₁ with a large capacity rating and the auxiliary storage battery B ₂ with a small capacity rating are supplied with a sinusoidal charging current by D ₁ , and the peak value in each cycle of the sinusoidal waveform of the charging current is detected, and the peak value is detected. A switching circuit section 4 switches charging current supply to each of the storage batteries B ₁ and B ₂ depending on the height, and the switching circuit section 4 changes the charging time of the auxiliary storage battery B ₂ to the charging time of the main storage battery B ₁ . Since the supply to sub-storage battery B ₂ is stopped when it is detected that the peak value exceeds a predetermined height, multiple storage batteries with different rated capacities can be filled almost simultaneously. It can be recharged and will not cause deterioration due to overcharging of storage batteries with small rated capacity.

[Brief explanation of drawings]

The figure shows an embodiment of the present invention.
The figure is an electric circuit diagram of the charging device, Figure 2 is a current waveform diagram, and Figure 3 is an electric circuit diagram of another embodiment of the present invention.
FIG. 4 is a current waveform diagram. 1...AC power supply, 4,7...Switching circuit, _B1 ...Main storage battery, _B2 ...Sub-storage battery, _D1 ...
Rectifier section.

Claims (1)

[Claims] 1. A rectifier _D1 that rectifies the AC power source 1, a main storage battery _B1 with a large capacity rating, and a secondary storage battery B with a small capacity rating, to which a sinusoidal charging current is supplied by the rectifier _D1 . ₂ , and a switching circuit unit 4 that detects the height of the peak value in each cycle of the sinusoidal waveform of the charging current and switches the charging current supply to each of the storage batteries B ₁ and B ₂ according to the height, The circuit section 4 includes the sub-storage battery B ₂
A charging device that stops supplying to the auxiliary storage battery B2 when it is detected that the peak value exceeds a predetermined height so that the charging time of the main storage battery _B1 becomes shorter than the charging time of the main storage battery _B1 .