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: A system and method for reducing torque ripple in a motor controller includes a step (60) of measuring an output voltage at each phase of the motor controller. A next step (61) includes determining a voltage mismatch between the phases. A next step (62) includes phase grounding one phase of the motor. A next step (63) includes calculating a voltage gain for the phases to compensate for voltage mismatches therebetween. The compensating gain can include a gain and/or offset, which are applied as a function of motor angle and is used to generate a PWM signal for driving the motor with reduced torque ripple.

Abstract: A method (100) of controlling an inverter in an electronic ballast for at least one gas discharge lamp protects the inverter from damage due to lamp fault conditions, and provides enhanced noise immunity and multiple ignition attempts for low-temperature lamp starting. The method (100) includes repeating a filament preheating step and a frequency shifting step up to a predetermined number of times in order to facilitate lamp ignition under low-temperature conditions and to verify the legitimacy of a detected lamp fault.

Abstract: An electronic ballast (300) for powering at least one gas discharge lamp (10) includes an inverter (400), an output circuit (700), a lamp fault detection circuit (800), and an inverter control circuit (500). Ballast (300) operates according to an inverter control method (100) that includes repeating a filament preheating step and a frequency shifting step up to a predetermined number of times in order to facilitate lamp ignition under low-temperature conditions and to verify the legitimacy of a lamp fault. Inverter control circuit (500) is well-suited for implementation as a custom integrated circuit. Ballast (300) optionally includes an overcurrent detection circuit (820') with an adjustable lamp fault detection threshold that provides decreased sensitivity during lamp starting and enhanced protection after lamp ignition.

Abstract: An electronic power supply (100) receives power from an AC source (10) and supplies power to a load (20) that is referenced to earth ground (30). Power supply (100) comprises a power converter (200) and a voltage regulator (400). Power converter (200) draws a ground leakage current from AC source (10) and is capable of providing a steady-state output current having an average value that is greater than that of the ground leakage current. Voltage regulator (400) limits the output voltage of the power converter (200) to a predetermined level. In a preferred embodiments power converter (200) is implemented as a self-oscillating converters and power supply (100) draws a ground leakage current that is sufficiently small to meet regulatory limits and to avoid tripping of conventional ground-fault interrupters.

Abstract: An energy control system (10) comprises at least one controllable load (110), a master controller (200), a traveler wire (300) and at least one remote switch (400). The master controller (200) transmits control commands that effect corresponding control actions in the controllable load (110). The remote switch (400) transmits remote commands to the master controller (200) over the traveler wire (300). The energy control system (10) is well suited for installation in standard three-way switch or four-way switch electrical systems and requires neither additional wiring nor complicated installation procedures.

Abstract: An electronic power supply circuit (50) that includes a rectifying circuit (14), a boost converter (16), an in-rush current reduction circuit (52), and a bulk capacitor (18). The in-rush current reduction circuit (52) includes an in-rush current limiting resistor (54) and a bypass capacitor (56) that are connected in parallel with each other. An improved version of the in-rush current reduction circuit (52) includes a bypass diode (58) connected in parallel with the in-rush current limiting resistor (54) and bypass capacitor (56) which is oriented to provide a path for current flowing out of bulk capacitor (18). One particular application of the disclosed circuit is for use in an electronic ballast for fluorescent lamps.

Abstract: A power supply (10) for powering a load (500) includes an inverter (100), a series resonant output circuit (200), and a bootstrap power source (300) for supplying operating power to an inverter driver circuit (110). The bootstrap power source (300) is coupled in series with the load (500) via a dc blocking capacitor (240) and provides automatic shutdown of the inverter (100) by ceasing to supply operating power to the inverter driver circuit (110) when the load (500) fails to conduct current or is removed.

Abstract: An electronic power supply (10) includes a boost converter (100) and an inverter (600). The inverter (600) includes a first inverter node (602) having a periodically varying voltage, and a second inverter node (604) having a voltage with a peak value that is proportional to the dc output voltage of the boost converter (100). The boost converter (100) includes a control circuit (200) for driving a boost FET (110). Control circuit (200) includes a shunt circuit (300) having a shunt switch (308) for periodically turning off the boost FET (110), a drive source network (400) that is coupled to the first inverter node (602), and a load regulation network (500) that is coupled to the second inverter node (604). In a preferred embodiment, the power supply (10) includes a rectifier circuit (40) and a push-pull inverter (600), and is adapted to serve as an electronic ballast for powering at least one fluorescent lamp (702).

Abstract: An energy monitoring and control system (10) for use with a conventional AC source (12) having a hot wire and a neutral wire (28). The energy monitoring and control system (10) includes a control station (14) and a number of controllable loads (20). The control station (14) is coupled in series with the hot wire of the AC source and is physically located between the AC source (12) and the loads (20). The individual loads are connected in parallel with each other and are coupled to the AC surce (12) and the control station (14). The control station (14) can communicate with the loads in various ways, a preferred scheme being a power-line communication method. Each of the loads is equipped with circuitry for receiving and executing commands sent by the control station (14). The control station (14) can receive information from the loads (20) by observing the AC supply current drawn by the loads (20).

Abstract: A ballast circuit for driving a gas discharge having a source of pulsating and rectified AC (20), an energy storage circuit (30), a switch (40) that can have one end connected to an energy storage inductor and an opposite end that can be connected to circuit common; a control circuit (50) for opening and closing the switch (40) at a rate that is a function of at least a DC control current, a resonant circuit (60) that is coupled to the energy storage circuit (30) for energizing the gas discharge lamp.

Abstract: A multi-resonant circuit has a series-resonant circuit coupled to the input of an inverter. The output of the inverter is coupled to a parallel resonant circuit. The output of the parallel resonant circuit energizes a load, which could be gas discharge lamps. The operating frequency of the inverter is between the resonant frequency of the series resonant circuit and the resonant frequency of the parallel resonant circuit.

Abstract: A ballast circuit uses an optocoupler to provide electrical isolation of the dimming control from the remainder of the ballast. The optocoupler is operated in the linear range to provide continuous dimming of the lamps. The circuit further uses a combination of diodes and a diode bridge to steer current from the current sensor during lamp out conditions so that the inverter will maintain operation at a low frequency, thereby maximizing the output voltage. A clamp winding is used to insure that the voltage does not exceed the DC rail voltage.

Abstract: A DC power source is capable of automatically adapting to either a 120 or 240 VAC input and of providing a single regulated output range for either of the AC voltage levels provided thereto. The power source detects the AC input voltage and automatically doubles the lower voltage while allowing the higher rectified voltage to pass through. The power source includes an electronic switching arrangement responsive to the input voltage level for automatically doubling the lower AC input voltage when detected as well as timing circuitry to allow for transitory fluctuations in the input voltage level while maintaining a level DC output voltage.

Abstract: A stepping motor is described having two operative modes, the first mode being a normal rotary mode and the second a stationary mode. During rotary operation, the induced energy created by interruption of the current flow through the energized phase winding is dissipated quickly by a zener diode connected across the winding. In the stationary mode, a pulsed current is fed to one of the phase windings of the motor to assure stationary positioning of the rotor. During stationary operation, the zener diode is shunted with a second conventional diode providing a low impedance path to the current induced in the phase winding upon de-energization. This low impedance path greatly reduces the energy dissipated during the off condition of the pulsed current thereby greatly reducing motor power requirements during stationary operation.

Abstract: A D.C. to D.C. converter including a start circuit having a choke with a primary winding and a start winding. A portion of the input power is fed through a section of the start winding to the base of a switching transistor connected in series with the primary winding. The transistor is operated as a blocking oscillator by the start circuit and a voltage is induced across a secondary winding of the choke. The secondary voltage is rectified and fed to the control input of a pulse width modulator. In response to a predetermined level of the secondary voltage, the output of the pulse width modulator is coupled to the base of the transistor and the start circuit disabled. Current overload and transient voltage protection circuits are also included.