JPH058763Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a charger that can charge a plurality of types of secondary batteries that have consumed power through discharge.

[Summary of the idea]

The present invention includes a ΔV value detection circuit that detects the point at which the voltage drops at the end of charging in order to terminate charging of a secondary battery that has consumed power due to discharge, and a timer that sets the final charging time. Prepared and 2
By providing a detection section that detects information regarding the capacity from the notch of the secondary battery, and a time setting circuit that is activated by the output of this detection section and sets the final charging time of the secondary battery to the timer, the capacity can be increased. 2 different
This allows the next battery to be charged properly.

[Conventional technology]

In portable electronic devices, such as video tape recorders, tape recorders, radios, etc., rechargeable secondary batteries, such as Nikkad batteries, are used as power sources, depending on the type of electronic device, or one
A plurality of types of secondary batteries with different capacities are available for different types of electronic devices. Therefore, when charging a small-capacity secondary battery with a constant current, as shown by curve A in the time-charging voltage characteristic diagram in Figure 5, if charging is started at time T ₀ , the maximum value will be reached at time T ₁ . The charging voltage V _M becomes the charging voltage V M, and the charging voltage V _C obtained by dropping the voltage (ΔV) from the maximum charging voltage V _M is detected by the ΔV value detection circuit, and charging is terminated at time T ₂ .

However, in case the charging voltage V _C cannot be detected by the ΔV value detection circuit, the timer is activated at the initially set time T ₃ (for example, 10 to 15 minutes have elapsed from time T ₂ ), and the secondary It has been considered to configure the battery so that charging of the battery is forcibly terminated.

In addition, in the case of a large capacity secondary battery, as shown by curve B in FIG. 5, charging is performed in the same way as a small capacity secondary battery, although the charging time is longer.

[Problem that the invention attempts to solve]

If the charger is equipped with a ΔV value detection circuit, it can properly charge secondary batteries of different capacities, but if it is not equipped with a timer, safety is compromised.

Therefore, as mentioned above, if the ΔV value detection circuit detects the charging voltage V _C and also provides a timer that operates after a predetermined time has elapsed, a double safety device will be installed to ensure that the secondary battery is not overloaded after being charged. However, in this case, when charging a large-capacity secondary battery with a small-capacity charger, the timer operates before the ΔV value detection circuit, and the large-capacity secondary battery becomes insufficiently charged.

Therefore, a plurality of types of dedicated chargers corresponding to the types of secondary batteries used are required, which poses a problem of increased costs.

This idea was made to solve the above-mentioned problems, and by automatically switching the final charging time set on the timer based on the notch information provided in the secondary battery, To provide a charger that can appropriately charge a plurality of types of secondary batteries with different capacities.

[Means for solving problems]

The charger of this invention includes a ΔV value detection circuit, a detection section that detects notch information about the capacity arranged in the secondary battery, and the output of this detection section operates to determine the final charging time of the secondary battery. A time setting circuit is provided to set the timer.

[Effect]

The detection unit detects the notch in the secondary battery and operates the time setting circuit with the output of the detected capacity information to set the final charging time on the timer.
Multiple types of secondary batteries, each with a different capacity, can be charged appropriately.

〔Example〕

Figure 1 is a partially cutaway perspective view of the main parts of a charger showing an embodiment of this invention, Figure 2 is a block diagram showing the charging circuit, and Figures 3a and b are different types of secondary batteries. FIGS. 4a and 4b are explanatory diagrams showing the charging state.

In FIG. 1, reference numeral 1 denotes a charger, and as shown in FIG. 3, an insertion section 2 into which different types of secondary batteries B ₁ and B ₂ are inserted is provided. A micro switch 3 and only the upper end that presses the secondary batteries B ₁ and B ₂ toward the micro switch 3 are fixed to the insertion part 2 , and a spring 4 whose lower end is inserted into the casing is opposite to this spring 4 . An elastic electrode 5 for charging is provided on the side surface of the battery.

In FIG. 2, 6 is a step-down transformer, 7 is a rectifier diode, 8 is a normally open first switch, 9 is a second switch for final charging time switching, and the micro switch 3
Depending on the output of
Switched to b.

10A and 10B indicate CR circuits connected to the contacts 9a and 9b, and the CR circuit 10A is connected to the resistor Ra.
and a capacitor Ca, and the CR circuit 10B is composed of a resistor Rb and a capacitor Cb.

Reference numeral 11 indicates a normally closed third switch for charging, and 12 indicates a current detection circuit, which closes the first switch 8 by detecting the charging current.

13 indicates a ΔV value detection circuit that detects a charging voltage V _C that is a voltage drop of ΔV from the maximum charging voltage V _M ;
The third switch 11 is opened by detecting the charging voltage _VC .

Reference numeral 14 indicates a comparator that compares the charging voltage of the CR circuits 10A and 10B with the reference voltage V _T , and when the charging voltage of the CR circuit 10A or 10B of the CR circuit rises to the reference voltage V _T , the third switch 11 It is something that opens up the world.

R represents a resistor, and OR represents an OR circuit.

In FIG. 3, T indicates an electrode that contacts the electrodes 5 provided on the secondary batteries B ₁ and B ₂ , and D indicates a notch provided at the lower end corresponding to the micro switch 3 of the secondary battery B ₂ . show.

Note that the CR circuit 10A has a final charging time corresponding to the secondary battery _B1 , for example, the time _T3 shown in FIG.
A time constant circuit of a resistor Ra and a capacitor Ca such that the reference voltage V _T is reached at (for example, 10 to 15 minutes after the time _{T 2} when the ΔV value detection circuit 13 is expected to detect the charging voltage V C). It consists of

Further, the CR circuit 10B is connected to the final charging time corresponding to the secondary battery _B1 , for example, the time _T6 shown in FIG.
A time constant circuit of a resistor Rb and a capacitor Cb such that the reference voltage V _T is reached at (for example, 10 to 15 minutes after the time T ₅ when the ΔT value detection circuit 13 is expected to detect the charging voltage _V C). It consists of

Further, the secondary batteries B ₁ and B ₂ are shown with different capacities of charged power, and normally the secondary battery B ₁ with a large capacity is larger.

In this device configured as described above, when the secondary battery B 1 shown in FIG. 3a is inserted into the insertion portion 2 of the charger ₁ , the secondary battery B ₁ is pushed by the spring 4 and , the electrode 5 and the electrode T are in contact with each other, and the current value detection circuit 12 detects the charging current and closes the first switch 8.

At the same time, the secondary battery _B1 operates the micro switch 3, so the output of the micro switch 3 operates the switch 9, and the contact piece 9r is connected to the CR circuit 1.
Switch to contact 9a connected by 0A.

In this state, charging of the secondary battery _B1 is performed as described above. That is _, as shown by curve _A in _FIG .
When detected, the third switch 11 is opened and charging of the secondary battery _B1 is completed.

However, if the charging voltage V _C cannot be detected by the ΔV value detection circuit 13, the third switch 11 is opened at time _T3 when the voltage of the CR circuit 10A becomes the reference voltage V _T , so that the secondary battery B ₁ , there is no risk of overcharging.

In addition, insert the secondary battery B ₂ shown in Figure 3b into the insertion section 2.
When the micro switch 3 is inserted into the secondary battery B for charging, as shown in Fig. 4b, the micro switch 3 is deactivated by the notch D and one end of the spring 4 is a free end. ₂ to secondary battery
Press with approximately the same pressing force as B ₁ , and the extra length of the spring 4 goes into the casing.

Then, the output of the micro switch 3 keeps the contact piece 9r of the switch 9 connected to the contact 9a connected to the CR circuit 10B.

In this state, charging of the secondary battery _B2 is performed as described above. That is _, as shown by curve _B in _FIG .
When detected, the third switch 11 is opened and charging of the secondary battery _B2 is completed.

However _, if the charging voltage V _C cannot be detected by the ΔV value detection circuit 13, the _third switch 1
1 is open, the secondary battery B ₂ will not be overcharged.

The charger 1 of this invention operates the switch 9 by automatically activating and deactivating the micro switch 3 with or without the notch D disposed in the secondary batteries B ₁ and B ₂ , Since the final charging times T ₃ and T ₆ can be set to predetermined times according to the charging capacity of the batteries, secondary batteries B ₁ , T 6 with different capacities can be
Even when charging _B2 , overcharging of each secondary battery can be prevented.

Furthermore, the spring 4 having one free end can press the secondary batteries B ₁ and B ₂ having different thicknesses with substantially the same pressing force, thereby bringing the electrode 5 and the electrode T into contact with each other.

It goes without saying that the timers are not limited to the CR circuits 10A and 10B, and may be other timers.

[Effect of idea]

As explained above, the charger of this invention is
A means for detecting the ΔV value, a detection section for detecting information regarding the notch provided in the secondary battery, and a time for setting the final charging time of the secondary battery in a timer operated by the output of this detection section. A setting circuit is provided, and the detection unit detects information about the capacity of the secondary battery, and the final charging time is automatically set on the timer, making it possible to charge multiple types of secondary batteries with different capacities. Even if charging is not completed due to the output of the ΔV value detection circuit, overcharging is prevented by the time setting section set for each type of secondary battery, and the battery is always properly charged. There is an advantage that charging is performed.

[Brief explanation of drawings]

Figure 1 is a partially cutaway perspective view of the main parts of a charger showing an embodiment of this invention, Figure 2 is a block diagram showing the charging circuit, and Figures 3a and b are different types of secondary batteries. FIGS. 4a and 4b are explanatory diagrams showing the charging state, and FIG. 5 is a time-charging voltage characteristic diagram when the charging current is constant. In the figure, 1 is a charger, 2 is an insertion part, 3 is a micro switch, 4 is a spring, 5 is an electrode, and 8 is a first
switch, 9 is the second switch, 10A, 10
B is a CR circuit, 11 is a third switch, 13 is a ΔV value detection circuit, 14 is a comparator, B ₁ and B ₂ are secondary batteries, and D is a notch.

Claims (1)

[Scope of Claim for Utility Model Registration] A ΔV value detection unit 13 that detects a charging voltage that has dropped by a predetermined voltage (ΔV value) from the maximum charging voltage, and a timer unit 10A, 10 that measures the final charging time.
B, and 2 installed and inserted in the secondary battery insertion part 2.
A spring 4 presses the secondary battery toward the micro switch 3 and presses the electrodes of the inserted secondary battery and the electrodes of the charger, and the micro switch detects the presence or absence of a notch in the inserted secondary battery; and a time setting section 9 for setting a final charging time in the timer section based on information regarding the detected capacity of the secondary battery, and when a ΔV value is detected by the ΔV value detection section,
Alternatively, a charger characterized in that secondary batteries of different capacities can be appropriately charged by terminating charging at one of the times when the final charging time is measured by the timer section.