Delco Electronics Corporation

Delphi Technologies, Inc.

Alfred Henry Barrett

Joel Franklin Downey

Richard F Rouser

Gary Andrew Cameron

Bishara Assad Tahhan

An improved gate drive circuit powered by a DC source voltage, the drive circuit having an isolated output stage with a parallel-connected by-pass capacitor and a switched input capacitor circuit that maintains a charge on the by-pass capacitor for driving the gate of a controlled MOS transistor while isolating the by-pass capacitor from the source voltage. In a fully isolated embodiment of the improved gate drive circuit, a bank of controlled switches alternately couples the input capacitor to the source voltage and the by-pass capacitor, while in another embodiment, uni-directional isolation is achieved by replacing one or more of the controlled switches with diodes.

Isolated gate drive circuit having a switched input capacitor

An improved motor vehicle electrical system includes a flexible topology DC-to-DC converter for coupling an engine-driven alternator to vehicle electrical loads at a mode-dependent transfer ratio. The output voltage of the alternator is regulated based the load voltage, and the converter is operable in one of a number of different modes based on engine speed, including a forward boost mode, a forward unity mode, and a forward buck mode. In the forward boost mode, the converter output voltage is boosted above that of the alternator to enable battery charging at low engine speeds; in the forward unity mode, the alternator output voltage is transferred to the battery and electrical loads at a unity transfer ratio; and in the forward buck mode, the converter output voltage is reduced below that of the alternator to enhance the alternator power output at medium-to-high engine speeds. In applications where a single electrical machine is utilized for both starting and generating functions, the converter is capable of operation in a reverse buck mode during engine starting for purposes of increasing the current supplied to the machine.

Multi-mode converter for a motor vehicle electrical system

An improved low-cost gate drive circuit drives the bridge transistors of a multiple power supply bridge circuit with a single logic level voltage. In general, the single logic level voltage is referenced to a first power supply and provides gate drive voltages for bridge transistors associated with a second power supply. The logic level voltage is bootstrapped to a first by-pass capacitor to provide a first gate drive voltage for a high-side transistor associated with the first power supply, and the charge on the first by-pass capacitor is consecutively bootstrapped to second and third by-pass capacitors to provide second and third gate drive voltages for bridge transistors associated with the second power supply.

Multiple output bootstrapped gate drive circuit

An improved dual voltage automotive electrical system in which low voltage loads are powered by a series resonant DC-DC converter operated at a fixed switching frequency below the resonant frequency of its tank circuit. With this arrangement, the converter provides a fixed conversion ratio from the regulated upper system voltage, and operates with the beneficial attributes of zero current switching and inherent overload protection. In a first embodiment, a transformer inductively couples the converter tank circuit to the low voltage loads, providing full input/output galvanic isolation. In a second embodiment, the converter is configured so that a portion of the power supplied to the low voltage loads is directly coupled from the upper system voltage source, with the remaining portion being coupled through the converter. In either embodiment, the accuracy of the conversion ratio and its load current independence are enhanced by a compounding coil having a load current dependent inductance coupled to the tank circuit.

Dual voltage automotive electrical system with sub-resonant DC-DC

A transformer assembly in which an isolation transformer and two additional inductor elements of a series/parallel resonant converter are physically integrated in a cost and space-efficient design. The transformer and two inductors are integrated through the simultaneous control of the leakage inductance and the magnetizing inductance of the assembly. The primary and secondary windings of the transformer are wound in a prescribed manner on a closed-path ferromagnetic core, the magnetizing inductance of the unit being determined by the desired inductance of second inductor, and the leakage inductance of the unit being determined by the inductance of the first inductor, which predominates the total series inductance of the tank circuit. The desired magnetizing inductance is achieved by controlling an air gap disposed in the magnetic flux path of the core, while the desired leakage inductance is achieved by winding a certain portion of the secondary turns on a loosely coupled leg of the core. A non-magnetic housing and spring clamp hold the assembly and maintain the air gap constant.

Series resonant converter transformer assembly having integral inductor

An improved sub-resonant converter which retains the advantages generally associated with simple series resonant converters while additionally providing improved form factor and efficiency, and reducing EMI. The overall tank circuit includes at least a first inductor and first capacitor connected in series, a second capacitor connected in parallel with the load circuit, and a second inductor connected in parallel with the second capacitor for providing voltage boost capability. In addition to reducing dv/dt in the load circuit, the second capacitor draws a current that has the effect of reducing the form factor of the supplied current while shortening the negative portion of its cycle so that reverse current through the anti-parallel diode of one switching device is terminated, or nearly so, by the turn on of the next switching device, thereby reducing EMI associated with a rapid initial rise in current at such turn on. In a preferred embodiment, the tank circuit also includes a third inductor connected in parallel with the first capacitor to narrow the switching frequency range, thereby extending the above-described form factor and EMI improvements over the entire load range of the converter. In addition, the tank circuit is preferably coupled to the load circuit via an isolation transformer.

Sub-resonant series resonant converter having improved form factor and

An LC resonant circuit. The resonant circuit includes a resonant capacitor and a transformer. The transformer comprises a magnetic core having a primary winding, secondary winding and control winding wound on the core. The primary winding is loosely coupled with the secondary winding. The resonant capacitor of the circuit is connected in series with the primary winding of the transformer. The control winding saturates the core in response to the application of direct current thereto to control the output of the resonant circuit.

Controlled-K resonating transformer

A push-pull or forward switching power supply is operable over a voltage range of 4.5 to 40 volts at high efficiency. At low voltages a primary winding or pair of windings are activated by a PWM control to regulate the output current. At high voltages, an additional primary winding in series with each of the other winding or windings is also activated by a PWM control.

Extended range switch mode power supply

An LC resonant circuit for a resonant converter includes a resonant capacitor and an inductor coupled to a fixed frequency AC supply. A controlled inductor in parallel with the resonant capacitor is controlled by a DC current to vary its inductance. The controlled inductor comprises a magnetic core having one or more power windings, and a control winding wound on the core. The DC current in the control winding produces core flux which effects core permeability. The controlled inductor has the effect of changing the capacitor impedance and thus influences the converter output. Multiple, independently controlled and regulated outputs may be driven by one power switching stage.

Resonant converter with controlled inductor

A multi-phase AC to DC harmonic neutralizing power converter. The power converter includes a plurality of non-isolated inputs for respective phases of a multi-phase source of AC power and a plurality of first rectifiers connected respectively to the inputs. A multi-phase harmonic neutralizing converter includes a power switching inverter having an input connected to the outputs of each of the first rectifiers, the inverter including LC resonant circuits. A plurality of second rectifiers having respective inputs connected to the output of the inverter through a plurality of respective transformers having outputs that are connected in voltage additive relationship to the outputs of the respective individual phase first rectifiers.

Multi-phase power converter with harmonic neutralization

An AC/DC harmonic neutralizing power converter. The power converter includes a first rectifier, load output terminals for delivering DC power to a load, and a harmonic neutralizing converter. The first rectifier includes an input to receive AC input power and an output. The harmonic neutralizing converter comprises a power switching inverter and a second rectifier. The power switching inverter includes an input connected to the output of the first rectifier, an LC resonant circuit comprising a series connected capacitor and inductor, and an output. The second rectifier of the harmonic neutralizing converter has an input connected to the output of the inverter and an output connected in voltage additive relationship to the output of the first rectifier. The added outputs of the rectifiers is connected to the load output terminals such that the output voltage on the load output terminals substantially equals the added output voltages of the rectifiers. In this manner, the power converter draws from the power source substantially sinusoidal current of a frequency substantially equal to the frequency of the input signal provided by the AC power source. Various disclosed embodiments include the use of a neutralizing autotransformer, an isolating transformer to provide for inductive coupling to a battery and full-bridge switching.

Power converter with harmonic neutralization

An AC/DC harmonic neutralizing power converter. The power converter includes a first rectifier, load output terminals for delivering DC power to a load, and a harmonic neutralizing converter. The first rectifier includes an input to receive AC input power and an output. The harmonic neutralizing converter comprises a power switching inverter and a second rectifier. The power switching inverter includes an input connected to the output of the first rectifier, an LC resonant circuit, and an output. The second rectifier of the harmonic neutralizing converter has an input connected to the output of the inverter and an output connected in voltage additive relationship to the output of the first rectifier. The added outputs of the rectifiers is connected to the load output terminals such that the output voltage on the load output terminals substantially equals the added output voltages of the rectifiers. In this manner, the power converter draws from the power source substantially sinusoidal current of a frequency substantially equal to the frequency of the input signal provided by the AC power source. Various embodiments are also illustrated in which the power converter is controlled without modifying the operating frequency of the resonant circuit of the power switching circuit. This may be accomplished by inclusion of an additional output stage, a bootstrap circuit, and use of a controlled-K resonant transformer in the series resonant circuit. By using series resonant topology within the harmonic neutralizing power converter, harmonic neutralization is accomplished using a topology which is inherently advantageous over pulse width modulation power converters.

A multi-phase AC to DC harmonic neutralizing power converter. The power converter includes a plurality of inputs for respective phases of a multi-phase source of AC power and a plurality of first rectifiers connected respectively to the inputs. A multi-phase harmonic neutralizing converter includes a power switching inverter having an input connected to the outputs of each of the first rectifiers, the inverter including LC resonant circuits. A plurality of second rectifiers having respective inputs connected to the output of the inverter through a plurality of respective transformers having outputs that are connected in voltage additive relationship to the outputs of the respective individual phase first rectifiers. A single set of power switches is utilized to neutralize multiple input power phases.

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Carmel, IN, United States of America

Alfred Henry Barrett