Abstract:
Disclosed herein is an electrical system topology for voltage regulation in a 12-volt vehicle power distribution system. Particularly, a single transistor power converter is configured to operate in both as a traditional voltage regulator mode (i.e., as buck converter to reduce the field voltage applied to an alternator to a value less than that available from the main bus) and as an alternator field current boost converter (i.e., as a boost converter to boost the field voltage applied to an alternator to a value greater than that available from the main bus). The converter may also include a controller that incorporates a thermal model of the alternator to limit the amount of voltage boost applied and/or direct temperature measurement of the alternator or alternator components. Additionally, these two approaches may be combined such that measured temperatures are used to refine the temperature estimated by the thermal estimator.
Abstract:
Disclosed herein is an automotive electrical system including a FET based rectifier and method of controlling the FET based rectifier without using either an alternator shaft position sensor or current sensors on each phase of the alternator output to control the switching of the FETs. In accordance with the teachings herein, the voltage and current on the DC bus of the automotive electrical system are sensed and switching of the FETs is controlled by a microcontroller that determines the appropriate switching times based on these sensed parameters.
Abstract:
A system for programming control of ballast illumination includes receiving a power stage input current through a first ballast input, receiving a level switch control signal at a second ballast input, entering a ballast illumination program mode, adjusting said level switch control signal to select a ballast lamp illumination and saving a field-programmed ballast lamp illumination indication in a ballast memory as representative of said ballast lamp illumination.
Abstract:
Disclosed herein is an automotive electrical system including a FET based rectifier and method of controlling the FET based rectifier without using either an alternator shaft position sensor or current sensors on each phase of the alternator output to control the switching of the FETs. In accordance with the teachings herein, the voltage and current on the DC bus of the automotive electrical system are sensed and switching of the FETs is controlled by a microcontroller that determines the appropriate switching times based on these sensed parameters.
Abstract:
Disclosed herein is an electrical system topology for voltage regulation in a 12-volt vehicle power distribution system. Particularly, a single transistor power converter is configured to operate in both as a traditional voltage regulator mode (i.e., as buck converter to reduce the field voltage applied to an alternator to a value less than that available from the main bus) and as an alternator field current boost converter (i.e., as a boost converter to boost the field voltage applied to an alternator to a value greater than that available from the main bus). The converter may also include a controller that incorporates a thermal model of the alternator to limit the amount of voltage boost applied and/or direct temperature measurement of the alternator or alternator components. Additionally, these two approaches may be combined such that measured temperatures are used to refine the temperature estimated by the thermal estimator.
Abstract:
Disclosed herein are two techniques, neutral point switching and field voltage boost, that will increase the output of today's 12 volt automotive electrical systems in vehicle idle conditions solely by the addition of circuitry. Neutral point switching enables the flow of a third harmonic current, which does not normally flow at low speeds, but only at high speed. Boosting the field voltages can be obtained by integrating a field voltage boost circuit and voltage regulator to increase the field voltage, and consequently the field current, above the level obtained from the battery. Furthermore, the transient response of the alternator to a change in load is improved by temporarily increasing the field voltage above the level needed to sustain the load. These two techniques are compatible, and thus may be implemented together, or may be implemented independently. No changes to a standard alternator are required to accommodate the proposed additional circuitry.
Abstract:
An apparatus and method for driving a halogen lamp. A driving circuit is provided that is operable near a series resonance frequency. The driving circuit is coupled to the lamp in a series configuration. During startup, the circuit is driven above resonance. After the lamp has warmed up, the circuit is driven substantially at resonance. A controller is coupled to the driving circuit. The controller is operable to control the frequency of operation of the driving circuit.
Abstract:
Disclosed herein are a variety of different electrical system topologies intended to mitigate the impact of large intermittent loads on a 12 volt vehicle power distribution system. In some embodiments the intermittent load is disconnected from the remainder of the system and the voltage supplied to this load is allowed to fluctuate. In other embodiments, the voltage to critical loads is regulated independently of the voltage supplied to the remainder of the system. The different topologies described can be grouped into three categories, each corresponding to a different solution technique. One approach is to regulate the voltage to the critical loads. A second approach is to isolate the intermittent load that causes the drop in system voltage. The third approach is to use a different type of alternator that has a faster response than the conventional Lundell wound field machine.
Abstract:
Disclosed herein is an automotive electrical system including a FET based rectifier and method of controlling the FET based rectifier without using either an alternator shaft position sensor or current sensors on each phase of the alternator output to control the switching of the FETs. In accordance with the teachings herein, the voltage and current on the DC bus of the automotive electrical system are sensed and switching of the FETs is controlled by a microcontroller that determines the appropriate switching times based on these sensed parameters.
Abstract:
Disclosed herein are two techniques, neutral point switching and field voltage boost, that will increase the output of today's 12 volt automotive electrical systems in vehicle idle conditions solely by the addition of circuitry. Neutral point switching enables the flow of a third harmonic current, which does not normally flow at low speeds, but only at high speed. Boosting the field voltages can be obtained by integrating a field voltage boost circuit and voltage regulator to increase the field voltage, and consequently the field current, above the level obtained from the battery. Furthermore, the transient response of the alternator to a change in load is improved by temporarily increasing the field voltage above the level needed to sustain the load. These two techniques are compatible, and thus may be implemented together, or may be implemented independently. No changes to a standard alternator are required to accommodate the proposed additional circuitry.