Ericsson Gmbh

Advanced Battery Management, LLC

William Hart

Richard W Farrington

Jun Zhang

John Arthur Fee

Claes Svardsjo

Thomas W Moller

Robert Joseph Miles

Gary Joseph Tole

Brian L Graham

Mark N Sun

Robert Bartola

James Mogel

Laszlo Szerenyi

A battery charger with a fixed frequency charging signal at or near the resonant frequency of the battery to be charged is presented. The present invention utilizes a microprocessor to modulate a current source at or near the resonant frequency of the battery to be charged without the use of a PLL. To simplify conventional modulated battery chargers, the PLL or other methods of phase correction are removed, reducing most of the calculation requirements for adjusting the phase angle, thereby reducing the piece count and ultimately cost and complexity. The result is a solution wherein charging occurs at or near the resonant frequency of the battery, and although suboptimal, the results are superior to traditional charging methods.

Method and apparatus to provide fixed frequency charging signals to a battery at or near resonance

A battery charger with a self-contained power source which provides a current charging signal at or near the resonant frequency of the battery to be charged when no other power supply is readily available. A storage energy device, for example a battery, delivers a current charging signal modulated at or near the resonant frequency of a load, or stores energy from a source.

Method and apparatus for a remote battery charger with a self contained power source

A constant gain, constant phase RF power block, e.g., for use in a RF amplifier apparatus. In a preferred embodiment, the power block includes a DC to DC power supply circuit co-located with an RF power transistor device on a common heat sink. The power supply circuit has as an input a varying DC voltage and as outputs a constant supply voltage and a constant bias voltage. The power device has as inputs the constant supply voltage and the constant bias voltage, and further configured to receive and amplify an RF signal. The power supply circuit preferably includes a first laser trimmable resistor for setting the constant supply voltage and a second laser trimmable resistor for setting the bias voltage. In this manner, the constant supply and bias voltages may be easily tuned to a desired level during assembly of the power block device. The input and amplified RF signals are each matched to a relatively high impedance, e.g., approximately fifty ohms.

Constant gain, constant phase RF power block

The present invention provides a method for preventing a fault condition in a DC-DC converter ( ) having a first secondary winding (Ns ) coupled to a first synchronous rectifier (SQ ) and a second secondary winding (Ns ) coupled to a second synchronous rectifier (SQ ). The first synchronous rectifier (SQ ) is turned on based on a voltage across the first secondary winding (Ns ) and is turned off based on a first driver signal. The second synchronous rectifier (SQ ) is turned on based on a voltage across the second secondary winding (Ns ) and is turned off based on a second driver signal. The present invention also provides a DC-DC converter ( ) wherein a first control circuit is coupled to and controls the first synchronous rectifier (SQ ) pursuant to the method described above, and a second control circuit is coupled to and controls the second synchronous rectifier (SQ ) pursuant to the method described above.

Method of connecting synchronous rectifier modules in parallel without output voltage faults

An inductor configuration (,) comprising a three-legged inductor core (,) with a first leg (,), second leg (,), and third leg (,) integrally extending from a base (,). The first leg (,) and second leg (,) are predisposed and spaced about a first surface (,) of the base (,) to form a first channel area (,). The second leg (,) also forms, along with the third leg (,), a second channel area (,) separated from the first channel area (,) by the second leg (,). The inductor also comprises an inductor winding (,) arranged about the inductor core (,) to provide relatively equal magnetic flux through the first leg (,), second leg (,), and third leg (,) when current flows through the inductor winding (,). The inductor configuration may be used as an input or output inductor for a synchronous rectifier circuit (,).

Split inductor with fractional turn of each winding and PCB including same

A self-driven synchronous rectifier circuit having synchronous rectifiers with floating gates for a power converter or signal transformer. The circuit comprises a transformer (,) having a secondary winding with a first and second terminal, a first synchronous rectifier (SQ,) coupled to the first transformer secondary winding first terminal and having a control terminal floating relative to ground and a first drive circuit coupled to the first synchronous rectifier floating control terminal and controlling the first synchronous rectifier. A first control signal is coupled to the first drive circuit, where the first control signal controls the first drive circuit as a function of a polarity reversal of a voltage across the first transformer (,). A second synchronous rectifier (SQ,) is coupled to the first transformer secondary winding second terminal and has a control terminal floating relative to ground. A second drive circuit is coupled to the second synchronous rectifier floating control terminal and controls the second synchronous rectifier. A second control signal is coupled to the second drive circuit, where the second control signal controls the second drive circuit as a function of a polarity reversal of a voltage across the first transformer (,).

General self-driven synchronous rectification scheme for synchronous rectifiers having a floating gate

A self-driven synchronous rectifier circuit (,) for a DC&mdash;DC power converter. The circuit comprises a primary transformer (,), a first synchronous rectifier (SQ,) coupled to the primary transformer (,), a second synchronous rectifier (SQ,) coupled to the primary transformer (,), an external drive circuit (,). The circuit (,) also comprises a plurality of switches (SQ,, SQ,) controllably coupled to second synchronous rectifier (SQ,). The external drive circuit (,) provides turn-off signaling for both synchronous rectifiers (SQ,, SQ,) Turn-on signaling provided for first synchronous rectifier (SQ,) by the primary transformer (,) turn-on signaling for second synchronous rectifier (SQ,) is provided by the external drive circuit (,).

Externally-driven scheme for synchronous rectification

A push-pull converter for converting an input voltage to a selectable output voltage is disclosed. The push-pull converter includes a pair of primary switches and a pair of primary windings of a transformer. The voltage stress across the primary switches is regulated by means of a clamp capacitor. The clamp capacitor clamps the voltage of the primary switches during the reset of the primary windings of the transformer. An alternate embodiment is also disclosed in which the voltage stress across the primary switches is regulated by means of two clamp capacitors. The clamp capacitor clamps the voltage of the primary switches during the reset of the primary windings of the transformer. The clamp capacitors extend the transformer reset period to include the lagging dead time for the corresponding switches, as well as the complementary powering stage. Current in the output section during the dead times is permitted by means of an additional diode, therein.

Push-pull power converter circuit

A rectifier circuit having voltage clamping circuitry is disclosed. The rectifier circuit includes a transformer having a primary winding and a secondary winding and transistor switches each being connected to an end of the secondary winding of the transformer. The rectifier circuit further includes a first diode having an anode terminal connected to a first end of the secondary winding and a second diode having an anode terminal connected to a second end of the secondary winding. The cathode terminals of the first and second diodes are coupled to a capacitor. The energy stemming from voltage spikes and/or high frequency ringing appearing at the transistor switches due to parasitic effects is effectively absorbed by the first and second diodes and collected in the capacitor. The collected energy is recycled to control the operation of the transistor switches.

Clamping circuit and method for synchronous rectification

An external driving circuit (21) for a bridge type synchronous rectifier circuit (20) having a first and second first synchronous rectifier (Q3,Q4), a primary driving circuit (14), and a pair of totem pole drivers (16,18). The timing signal for the first and second synchronous rectifiers (Q3,Q4) is derived from the external driving circuit (21). The external driving circuit (21) includes a first and second switch drivers (22,24). The external driving circuit (21) is interfaced with the synchronous rectifier circuit (20) by connecting first and second switch drivers (22,24) to the totem pole drivers (16,18). The first and second switch drivers (22,24) provides storage for circuit current which is fully discharged at the appropriate time to facilitate turning on and off the synchronous rectifiers (Q3,Q4).

External driving circuit for bridge type synchronous rectification

A self-driven synchronous rectifier circuit (42) for a power converter. The circuit comprises a transformer (49, 70) having a secondary winding with a first and second terminal, a first synchronous rectifier (14) coupled to the second transformer terminal and having a control terminal, and a second synchronous rectifier (16) coupled to the first transformer terminal and having a control terminal. The circuit (42) also comprises a first switch (44) coupled to the first synchronous rectifier (14) control terminal, and a second switch (46) coupled to the second synchronous rectifier (16) control terminal. The first (44) and second switch (46) are also coupled to the secondary winding. Switching transitions of the first (14) and second (16) synchronous rectifiers are initiated by a polarity reversal of the voltage of the secondary transformer winding.

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Plano, TX, United States of America

William Hart