Battery Charger and Method for its Operation
First Claim
1. A battery charger for charging a battery, the battery charger having a two-pole input for receiving a current (IN) and an AC voltage (UN), the battery charger comprising:
- a rectifier which has a two-pole output for connecting to the battery;
an RF storage transformer having a primary winding connected via a clock switch to the input of the battery charger, and a secondary winding connected in the form of a flyback converter to said rectifier;
a measurement unit, which detects the current (IN) and the voltage (UN) at the input of the battery charger; and
a controller which operates said clock switch as a function of the current (IN) and the voltage (UN) at the input of the battery charger.
1 Assignment
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Accused Products
Abstract
A battery charger having an RF storage transformer whose primary winding is connected via a clock to a two-pole input for receiving an AC voltage, and whose secondary winding is connected as a flyback converter to a rectifier with a two-pole output for the battery. The charger has a measurement unit, which detects the input current and voltage and a controller which operates the clock as a function thereof. A method for operating the charger, wherein the controller continually switches the clock on for a first interval and switches it off for a second interval, wherein the first interval ends when the current rises to a value corresponding to the instantaneous value of the voltage times a scaling factor, and the duration of the first and second intervals is sufficiently long that their total duration corresponds to the period of one interval of permissible operating frequencies of the transformer.
36 Citations
14 Claims
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1. A battery charger for charging a battery, the battery charger having a two-pole input for receiving a current (IN) and an AC voltage (UN), the battery charger comprising:
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a rectifier which has a two-pole output for connecting to the battery; an RF storage transformer having a primary winding connected via a clock switch to the input of the battery charger, and a secondary winding connected in the form of a flyback converter to said rectifier; a measurement unit, which detects the current (IN) and the voltage (UN) at the input of the battery charger; and a controller which operates said clock switch as a function of the current (IN) and the voltage (UN) at the input of the battery charger. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for operating a battery charger having a two-pole input for receiving an AC voltage, and comprising:
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a rectifier which has a two-pole output for connecting to the battery; an RF storage transformer having a primary winding connected via a clock switch to the input of the battery charger, and a secondary winding connected in the form of a flyback converter to said rectifier; a measurement unit, which detects current (IN) and voltage (UN) at the input of the battery charger; and a controller which operates said clock switch as a function of current (IN) and voltage (UN); the method comprising the steps of; continually switching said clock switch “
on”
for a first time interval (Δ
T1) and “
off”
for a second time interval (Δ
T2), wherein said first time interval (Δ
T1) ends when the input current (IN) has risen to a predetermined limit value (I0) which corresponds to the instantaneous value of the voltage (UN) multiplied by a predetermined scaling factor, and wherein said second time interval (Δ
T2) is chosen to be sufficiently long that the total duration of said first time interval (Δ
T1) and said second time interval (Δ
T2) corresponds to the period duration of one interval of permissible operating frequencies (fa) of said RF storage transformer. - View Dependent Claims (12, 13, 14)
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Specification