DC-DC conversion charging apparatus
First Claim
1. Method of charging a rechargeable device, comprising the following steps:
- a) connecting the rechargeable device to a battery connection port and ground;
b) feeding a current reference value to a control unit;
c) feeding a voltage reference value to the control unit;
d) determining a duty cycle in accordance with the current reference value and the voltage reference value fed to the control unit;
e) switching, using the duty cycle, an output voltage applied to the rechargeable device between a minimum output voltage and a maximum output voltage dependent on the current reference value and the voltage reference value by means of a charging switch; and
f) disconnecting the charged rechargeable device;
wherein the method further comprises the following step;
g) connecting an external DC source having an input voltage to an input resistor of a charging apparatus, wherein a transistor voltage drop across the charging switch is minimized in order to reduce a power dissipated by the charging switch-transistor;
h) wherein the duty cycle provided by the control unit is determined by the input voltage and the charging state of the rechargeable device.
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Accused Products
Abstract
The present invention provides a method of charging a rechargeable device (108) and a charging apparatus wherein the rechargeable device (108) is connected to a battery connection port (107) and ground (106), an external DC source having an input voltage (114) is connected to an input resistor (101) of a charging apparatus, a current reference value (109) and a voltage reference value (110) are fed to a control unit (104), a duty cycle (d) is determined in accordance with the current reference value (109) and the voltage reference value (110) fed to the control unit (104), and, using the duty cycle (d), an output voltage (402, 403) applied to the rechargeable device (108) is switched between a minimum output voltage (404) and a maximum output voltage (405) dependent on the current reference value (109) an the voltage reference value (110) by means of a charging switch (103).
13 Citations
9 Claims
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1. Method of charging a rechargeable device, comprising the following steps:
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a) connecting the rechargeable device to a battery connection port and ground;
b) feeding a current reference value to a control unit;
c) feeding a voltage reference value to the control unit;
d) determining a duty cycle in accordance with the current reference value and the voltage reference value fed to the control unit;
e) switching, using the duty cycle, an output voltage applied to the rechargeable device between a minimum output voltage and a maximum output voltage dependent on the current reference value and the voltage reference value by means of a charging switch; and
f) disconnecting the charged rechargeable device;
wherein the method further comprises the following step;
g) connecting an external DC source having an input voltage to an input resistor of a charging apparatus, wherein a transistor voltage drop across the charging switch is minimized in order to reduce a power dissipated by the charging switch-transistor;
h) wherein the duty cycle provided by the control unit is determined by the input voltage and the charging state of the rechargeable device. - View Dependent Claims (2, 3, 4, 5)
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6. Charging apparatus for charging rechargeable device, including:
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a) a battery connection port for connecting the rechargeable device to the charging apparatus;
b) a control unit for the determination a duty cycle in accordance with a current reference value and a voltage reference value fed to the control unit; and
c) a charging switch for switching according to the duty cycle, an output voltage applied to the rechargeable device between a minimum output voltage and a maximum output voltage dependent on the current reference value and the voltage reference value, wherein the charging apparatus further comprises;
d) an input resistor for connecting an external DC source having an input voltage to the charging apparatus, wherein i) a transistor voltage drop across the charging switch minimized in order to reduce a power dissipated by the charging switch-transistor;
ii) the input resistor is installed separately from the charging apparatus to deposit the power dissipated by the input resistor outside the charging apparatus; and
iii) the duty cycle provided by the control unit is determined by the input voltage and the charging state of the rechargeable device. - View Dependent Claims (7, 8, 9)
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Specification