Electricity: battery or capacitor charging or discharging – Battery or cell charging
Reexamination Certificate
2000-05-12
2001-04-17
Tso, Edward H. (Department: 2838)
Electricity: battery or capacitor charging or discharging
Battery or cell charging
C320S163000
Reexamination Certificate
active
06218811
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to output variable charging circuits and chargers using the same, and more specifically, the invention relates to output variable charging circuits incorporated in portable devices using secondary batteries as power supplies, and chargers using the same.
2. Description of the Related Art
FIG. 3
shows a circuit diagram of a conventional output variable charging circuit and a charger using the same.
In
FIG. 3
, an output variable charging circuit
1
has a charging control circuit
2
, electrolytic capacitors
3
and
4
, a current detection resistor
5
, a charging current detection circuit
6
, a charging voltage detection circuit
7
, a selector switch
8
, and a charging condition memory circuit
9
. The input of the charging control circuit
2
is connected to an external DC power supply
11
. In addition, the output of the charging control circuit
2
is connected to an external secondary battery
12
. Between the positive poles and negative poles of the input and the output of the charging control circuit
2
are connected an electrolytic capacitor
3
and an electrolytic capacitor
4
, respectively. Between the positive pole of the output of the charging control circuit
2
and the secondary battery
12
, the current detection resistor
5
is connected in series. In addition, both ends of the current detection resistor
5
are connected to the charging current detection circuit
6
, and a side of the current detection resistor
5
, where the secondary battery
12
is disposed, is connected to the charging voltage detection circuit
7
. The output of the charging current detection circuit
6
and the output of the charging voltage detection circuit
7
are connected to the charging control circuit
2
. Furthermore, the selector switch
8
is connected to the charging control circuit
2
via the charging condition memory circuit
9
. In this case, the charging current detection circuit
6
and the charging voltage detection circuit
7
together form a charging characteristic detection circuit
10
.
Furthermore, a charger
13
is formed by the output variable charging circuit
1
and the DC power supply
11
.
In the output variable charging circuit
1
and the charger
13
having such structures, the charging condition memory circuit
9
stores a plurality of charging conditions corresponding to various kinds of secondary batteries such as a lithium-ion battery, a nickel-hydrogen battery, and a nickel-cadmium battery, and circuits connected in series and parallel to the secondary battery. In this case, the charging conditions are referred to as determined values of a charging current and a charging voltage. One of the charging conditions is selected from the charging condition memory circuit
9
by using the selector switch
8
and is input to the charging control circuit
2
.
Meanwhile, the charging current detection circuit
6
detects a charging current from voltages of both ends of the current detection resistor
5
and gives a feedback as a charging current detection value to the charging control circuit
2
. The charging voltage detection circuit
7
detects a charging voltage and gives a feedback as a charging voltage detection value to the charging control circuit
2
. Such an actual charging current and an actual charging voltage represent charging characteristics. In addition, the charging current detection value and the charging voltage detection value obtained by detecting the charging characteristics by the charging characteristic detection circuit
10
are referred to as charging characteristic values. The charging control circuit
2
controls outputs in such a manner that the charging current detection value and the charging voltage detection value fed back from the charging current detection circuit
6
and the charging voltage detection circuit
7
can satisfy a charging condition input in advance from the charging condition memory circuit
9
.
In this way, the output variable charging circuit
1
can be used as a charging circuit which can be adapted to a plurality of secondary batteries or the combination thereof, whose charging conditions differ from each other, by using the selector switch.
Meanwhile, when the output variable charging circuit
1
is manufactured as a product to be used by a user, it is necessary to store in advance the kind of a secondary battery required for the user and charging conditions for circuits connected in series and parallel to the secondary battery in the charging condition memory circuit
9
. In this case, depending on the kinds of the charging conditions, the memory capacity of the charging condition memory circuit
9
or the number of times of switching performed by using the selector switch
8
is increased. As a result, this causes a problem in that the size and price of the output variable charging circuit
1
increase. In addition, since the output variable charging circuit
1
cannot adapt to charging conditions different from those stored in advance, for example, a new type of secondary battery, or a new combination of conventional secondary batteries, in this case, it is necessary to produce another output variable charging circuit adaptable to those by changing the contents stored in the charging condition memory circuit
9
and the like.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an output variable charging circuit capable of continuously changing charging characteristics such as a charging current and a charging voltage by using an external signal, and to provide a charger incorporating the output variable charging circuit.
To this end, the present invention provides an output variable charging circuit including a charging control circuit for controlling charging characteristics so as to satisfy a predetermined charging condition, and a charging characteristic detection circuit connected to the charging control circuit, the charging characteristic detection circuit detecting charging characteristics to obtain a charging characteristic detection value and changing the charging characteristic detection value according to an input external signal so as to give feedback to the charging control circuit.
In addition, the present invention provides an output variable charging circuit including a charging control circuit for controlling charging characteristics in such a manner that a predetermined charging condition is changed by an input external signal and the changed charging condition is thereby satisfied, and a charging characteristic detection circuit connected to the charging control circuit to detect the charging characteristics so as to obtain a charging characteristic detection value and feedback the charging characteristic detection value to the charging control circuit.
Furthermore, the output variable charging circuit of the present invention includes a signal conversion circuit for converting the external signal.
In addition, the present invention provides a charger including the output variable charging circuit described above, a DC power supply for supplying a DC current to the output variable charging circuit, and an external signal source for inputting an external signal to the output variable charging circuit.
According to the present invention, the output variable charging circuit includes the charging control circuit for controlling charging characteristics so as to satisfy the predetermined charging conditions, and the charging characteristic detection circuit connected to the charging control circuit to detect the charging characteristics so as to obtain a charging characteristic detection value, and to change the charging characteristic detection value according to an input external signal so as to allow the changed value to be fed back to the charging control circuit. With this arrangement, the charging characteristics such as a charging current and a charging voltage can be continuously changed according to the external signal. This can lead to cost reduction o
Murata Manufacturing Co. Ltd.
Ostrolenk Faber Gerb & Soffen, LLP
Tso Edward H.
LandOfFree
Output variable charging circuit and charger incorporating same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Output variable charging circuit and charger incorporating same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Output variable charging circuit and charger incorporating same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2534916