JPH0837033A - Charging device for storage battery - Google Patents

Abstract

PURPOSE:To prolong the lifetime of a battery by providing possibility of full charging of a storage battery whosh internal resistance has risen, with very simple operations. CONSTITUTION:The first bypass circuit 4 and second bypass circuit 5 are parallel installed from midway of a charger circuit A. The first bypass circuit 4 is equipped with a discharge circuit B consisting of a discharging resistor R1 and the first switch SW1 to open and close the first bypass circuit 4. The second bypass circuit 5 is equipped with a relay RL1, a transistor TR1 whose emitter terminal is connected with one of the terminals of the relay RL1 and collector terminal is connected with a charging power supply 1, and the second switch SW2 which puts on and off the charter circuit A and second bypass circuit 5. A Zener diode ZD1 is inserted between the second switch SW2 and the base terminal of transistor TR1, and a switching circuit C is furnished in connection through the protector resistance R2 of the diode ZD1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for a storage battery,
In particular, it relates to a charging device for a nickel-cadmium battery used in a mobile phone or the like.

[0002]

2. Description of the Related Art Nickel-cadmium batteries, which are alkaline storage batteries that use nickel oxide hydroxide for the positive electrode, cadmium for the negative electrode, and potassium hydroxide for the electrolyte, can be repeatedly charged, and are therefore used in mobile phones and video cameras. Widely used as a power source. Currently, this nickel-cadmium battery (hereinafter referred to as a battery) is charged using a charging device that rectifies a commercial AC power source and converts it into a DC voltage suitable for charging. These charging devices are usually attached to the battery-using device as described above, and the used battery is mounted and connected to the charging terminal for charging.

By the way, as the battery is repeatedly charged,
Despite the initial battery life and the allowable number of charge / discharge cycles within the specified range, full charge becomes impossible, which naturally shortens the battery usage time and causes a power shortage during use. There was a problem of doing. This occurs because the charged electricity is recharged before it is completely used up, that is, before the charged electricity is completely discharged. The reason is that the internal resistance gradually increases due to electricity remaining in the battery due to repeated charging before complete discharge, and the apparent voltage increases. For this reason, the instruction manual of the battery-powered device includes a note that the battery should be completely used up to charge.

[0004]

However, it is very difficult to observe the above-mentioned precautions during normal use of battery-powered equipment. In addition, although some of the dischargers for storage batteries are commercially available, it is difficult for general users who do not have knowledge of electrical equipment to use them. For this reason, the user is currently repeatedly charging and using the battery in the middle of discharging, and the usable time and the usable number of times according to the initially proposed battery standard cannot be achieved, and the user must replace the battery with a new one. The current situation is that no The present invention has been made in view of the above problems, and an object thereof is to provide a storage battery charging device capable of fully charging a storage battery whose internal resistance has risen and extending the life of the storage battery by an extremely simple operation. It is what

[0005]

Therefore, according to the present invention, in a storage battery charging device having a charging circuit for connecting a storage battery in series to a charging power source, a bypass circuit is provided in parallel with the charging circuit, and the bypass circuit is discharged. A first feature is that a discharging circuit having a resistor for use is provided and a switching circuit that switches between the charging circuit and the discharging path is provided, and the first and second bypass circuits are provided in parallel with the charging circuit. The first bypass circuit is provided with a discharging resistor and a discharging means having a first switch for opening and closing the first bypass circuit, and the second bypass circuit is provided with a relay and the relay. A transistor having an emitter terminal connected to the collector terminal and a collector terminal connected to a charging circuit, a second switch for opening and closing the charging circuit and a second bypass circuit, and the second switch. Switch and a Zener diode provided between the base terminals of the transistors are provided as a second feature, and in addition to the second feature, a third switch is connected in parallel with the second switch. The third feature is that a switch (push switch) is provided.

[0006]

The discharge resistor provided in the bypass circuit forcibly and completely discharges the electricity remaining in the battery to lower the internal resistance of the battery and enable full charge.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment of a storage battery charging device circuit according to the present invention, and FIG. 2 is a block diagram for explaining the present invention.

In FIGS. 1 and 2, reference numeral 1 is a charging power source obtained by rectifying a commercial AC power source and converting it into a DC voltage suitable for charging, and 2 is a charging power source terminal connected to a battery 3. The charging circuit A of the conventional charging device is configured. The first bypass circuit 4 and the second bypass circuit 5 are provided in parallel from the middle of the charging circuit A.

The first bypass circuit 4 has a discharge resistor R.
₁ and the first switch SW1 that opens and closes the first bypass circuit 4 form a discharge circuit B.

The second bypass circuit 5 includes a relay RL ₁
, A transistor TR ₁ having an emitter terminal connected to one terminal of the relay RL ₁ and a collector terminal connected to the charging power source 1, a charging circuit A, and a second bypass circuit 5
A second switch SW ₂ for opening and closing is provided, and a Zener diode ZD ₁ is provided between the second switch SW ₂ and the base terminal of the transistor TR ₁ via a protection resistor R 2 of the Zener diode ZD _1. A switching circuit C is connected and is configured. Here, the rated value of the Zener diode ZD ₁ is selected such that the Zener current is cut off when the voltage of the battery 3 becomes equal to or lower than the complete discharge voltage determined by the specification standard.

In short, the switching circuit C includes the relay RL ₁ , the first switch SW ₁ and the second switch SW.
₂ and 2 form a two-circuit two-contact relay, and the charging circuit A and the discharging circuit B can be switched alternately. In addition, a push switch PSW ₁ that is a third switch is provided in parallel with the second switch SW ₂ . By pushing the push switch PSW ₁ , the switching circuit C and the discharging circuit B are connected to form a closed circuit, and the charging circuit A can be opened. In the circuit diagram, D ₁ is a protection diode for the relay RL ₁ , and C ₁ and C ₂ are high frequency bypass capacitors for preventing malfunction.

Next, a method of using the storage battery charger according to this embodiment and the operation of the circuit will be described. This device is basically constructed by incorporating a discharging circuit B and a switching circuit C into the charging circuit at the manufacturing stage of the conventional charging device. First, the to-be-charged battery 3 (hereinafter referred to as the battery 3) is attached to the charging device, and the positive and negative polarities of the battery 3 are connected to the positive and negative polarities of the charging power supply terminal 2. Usually the first switch S
Since W ₁ is open and the tongue of the second switch SW ₂ is connected to the positive electrode of the charging power source 1, the fully discharged battery starts normal charging immediately by mounting it on the charging device. To be done.

Despite the battery's service life and allowable number of times of charging / discharging being within the standard, the battery 3 which is recognized to have a short continuous use time and an increased internal resistance is mounted on a charging device and then pushed. Press the switch PSW ₁ .
Hereinafter, the subsequent operation will be sequentially described. (A) When the push switch PSW ₁ is momentarily closed, the operating voltage is applied to the operating coil of the relay RL ₁ by using the residual voltage of the battery 3 as a power source. When (B) push switch PSW ₁ to the operating voltage is once applied, the first switch SW ₁ and the tongue closes the second switch SW2 is a relay tongue of the relay RL _1, the push switch PSW ₁ is Even after the relay is opened, the relay current continues to flow, and the operation of the relay RL ₁ is maintained. Therefore, the discharge circuit B and the switching circuit C can be maintained in the closed state. (C) When the first switch SW ₁ of the discharging circuit B is closed, the residual current of the battery 3 is consumed and discharged by the discharging resistor R ₁ . (D) When the discharge progresses, the internal voltage of the battery gradually drops, and when the voltage across the Zener diode ZD ₁ falls below the Zener voltage, the Zener diode ZD ₁ current becomes zero,
Naturally, the base current of the transistor TR ₁ becomes zero, so that the collector current is also cut off. (E) When the collector current of the transistor TR ₁ , that is, the current of the relay RL ₁ is cut off, the application of the operating voltage to the operating coil of the relay RL ₁ is stopped, and the first switch SW ₁ and the second switch SW ₂ is opened, the tongue of the second switch SW ₂ is connected to the positive electrode of the charging power source 1, the discharge circuit B is switched to the charging circuit, and the charging is automatically started.

The gist of the present invention resides in that a discharging circuit is installed in parallel with the charging circuit of the charging device, and a switching circuit for arbitrarily or automatically switching these two circuits is provided. Needless to say, the present invention is not limited to this example.

[0015]

As described above, the present invention has the following excellent effects. (1) It can be easily incorporated into a wide variety of commercially available charging devices and can be operated very easily. (2) The life of the storage battery can be extended by allowing the storage battery with increased internal resistance to be fully charged. (3) The operating power sources for the discharge circuit and the switching circuit are all obtained from the charged storage battery, and do not require any additional energy.

[0016]

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a storage battery charging device circuit according to the present invention.

FIG. 2 is a block diagram illustrating the present invention.

[Explanation of symbols]

1 Charging Power Supply 2 Charging Power Supply Terminal 3 Battery (Battery to be Charged) 4 First Bypass Circuit 5 Second Bypass Circuit R ₁ Discharge Resistor R ₂ Zener Diode Protection Resistor SW ₁ First Switch SW ₂ Second Switch RL ₁ relay ZD Zener diode TR ₁ transistor C ₁ high frequency bypass capacitor C ₂ high frequency bypass capacitor

Claims (3)

[Claims] 1. A storage battery charging device having a charging circuit for connecting a storage battery in series to a charging power source, wherein a bypass circuit is provided in parallel with the charging circuit, and discharging means having a discharging resistor is provided in the bypass circuit. A charging device for a storage battery, comprising switching means for switching between the charging circuit and the discharging circuit. 2. A storage battery charging device having a charging circuit for connecting a storage battery in series to a charging power source, wherein first and second bypass circuits are provided in parallel with the charging circuit, and the first bypass circuit comprises: Discharging means having a discharging resistor and a first switch for opening and closing the first bypass circuit is provided,
A relay, a transistor having an emitter terminal connected to the relay and a collector terminal connected to a charging circuit, and a second bypass circuit that opens and closes the charging circuit and the second bypass circuit. 2. The storage battery charging device according to claim 1, further comprising switching means including a switch and a zener diode provided between the second switch and the base terminal of the transistor. 3. The storage battery charging device according to claim 2, further comprising a third switch (push switch) connected in parallel with the second switch.