Abstract: A communications apparatus and techniques are presented for communicating with ballasts or drivers through lighting system power connections in which the power connections are energized with low levels of power to power communications components in the ballast/drivers while the light sources are off and low frequency AC communications signals are transmitted through the power connections.

Abstract: An interface circuit for a lamp ballast includes first and second input power lines, L1 and L2, with first and second respective switches, and a neutral power line N, all coupled to a diode bridge. Closing one of the first or second input power lines L1 or L2 causes a photodiode in an opto-isolator coupled to the diode bridge to turn ON, which in turn causes a MOSFET in a control circuit to be in an open state. When in the open state, a first resistor coupled to the source of the MOSFET is included in the control circuit and causes a lamp attached thereto to operate in a dimmed state. When both input power line switches are closed, L1 and L2 are both coupled to the diode bridge and thereby cause the phototransistor to be in an OFF state, which causes the MOSFET to close, thereby including a second resistor, coupled to the drain of the MOSFET, in the control circuit in parallel with the first resistor. This in turn causes the lamp to operate at full intensity.

Abstract: A risk of shock (ROS) protection circuit is disclosed, which comprises a capacitor that charges whenever there is a voltage between a ground on a lamp ballast and earth ground. If the capacitor exceeds a predetermined threshold voltage, the capacitor causes a gate to shunt current away from a tertiary winding in a control circuit, which in turn reduces impedance reflected by the tertiary winding back on to primary and secondary windings in the ballast circuit. The reduced reflected impedance causes the operating frequency of the ballast to increase, reducing the voltage between the ballast ground and earth ground until it is safe for human contact. In this manner, a human replacing a lamp connected to the ballast can be protected from shock despite a failure to disconnect the power to the lamp ballast prior to lamp replacement.

Abstract: Isolated LED power sources and DC-DC converters therefor are presented in which the DC-DC converter includes a self-oscillating inverter driving an output rectifier for operating an LED array of one or more LEDs, where the inverter uses a control transformer with core having a Curie temperature set to a maximum operating temperature of one or more power supply components to reduce inductances of secondary windings in the inverter oscillation circuitry to lower the power supplied to the load so as to prevent the inverter from overheating.

Abstract: A pre-programmed energy saving ballast or driver is presented, having a pre-defined energy profile to which the output power is controlled in accordance with the current time ascertained from the input power connection via simplex clock information or from received broadcast time signals, and which allows a user to select from a number of pre-programmed profiles and/or to modify and store user-defined energy profiles.

Abstract: A high efficiency low power DC driver apparatus is presented for powering a light source, with a capacitive divider circuit receiving an AC input and providing a divided AC output, a rectifier provide a DC output below ten watts, output terminals coupleable to one or more light sources, and a linear regulator coupled in series with the light source to regulate a drive current flowing through the series circuit.

Abstract: Fluorescent lamp ballasts and methods are disclosed in which a resonant impedance of a self-oscillating inverter is modified to control the inverter frequency to selectively preheat lamp cathodes using power from the inverter output during a preheating period after power is applied and to change the inverter frequency to a different range following ignition of the lamp.

Abstract: A high efficiency low power DC driver apparatus is presented for powering a light source, with a capacitive divider circuit receiving an AC input and providing a divided AC output, a rectifier provide a DC output below ten watts, output terminals coupleable to one or more light sources, and a linear regulator coupled in series with the light source to regulate a drive current flowing through the series circuit.

Abstract: A pre-programmed energy saving ballast or driver is presented, having a pre-defined energy profile to which the output power is controlled in accordance with the current time ascertained from the input power connection via simplex clock information or from received broadcast time signals, and which allows a user to select from a number of pre-programmed profiles and/or to modify and store user-defined energy profiles.

Abstract: Isolated LED power sources and DC-DC converters therefor are presented in which the DC-DC converter includes a self-oscillating inverter driving an output rectifier for operating an LED array of one or more LEDs, where the inverter uses a control transformer with core having a Curie temperature set to a maximum operating temperature of one or more power supply components to reduce inductances of secondary windings in the inverter oscillation circuitry to lower the power supplied to the load so as to prevent the inverter from overheating.

Abstract: A ballast circuit that facilitates providing thermal protection for a fluorescent lamp includes a coupling transformer that couples an inverter circuit to a control circuit. First and second transformer windings in the inverter circuit, and a third transformer winding in the control circuit, are wound around a common ferrite core. The ferrite core has a Curie temperature that approximates a maximum allowable threshold temperature for the lamp. When the temperature of the ballast approaches the Curie temperature of the ferrite core, its permeability, and thus inductance, drops dramatically, causing an increase in operating frequency in the inverter circuit. This increased operating frequency causes a capacitor in the control circuit to charge to a threshold voltage, at which power to the inverter circuit is reduced. The lamp then dims without turning off until the temperature is reduced to an acceptable level.

Abstract: A circuit for protecting an electronic ballast for use with a remote controller for gas discharge lamps against miswiring to a power source. Depletion mode MOSFETS are employed in both sides of the circuit to the controller and the MOSFETS respond to overvoltage, including polarity reversal to create an open circuit condition in the circuit to the controller.

Abstract: An interface circuit for a lamp ballast includes first and second input power lines, L1 and L2, with first and second respective switches, and a neutral power line N, all coupled to a diode bridge. Closing one of the first or second input power lines L1 or L2 causes a photodiode in an opto-isolator coupled to the diode bridge to turn ON, which in turn causes a MOSFET in a control circuit to be in an open state. When in the open state, a first resistor coupled to the source of the MOSFET is included in the control circuit and causes a lamp attached thereto to operate in a dimmed state. When both input power line switches are closed, L1 and L2 are both coupled to the diode bridge and thereby cause the phototransistor to be in an OFF state, which causes the MOSFET to close, thereby including a second resistor, coupled to the drain of the MOSFET, in the control circuit in parallel with the first resistor. This in turn causes the lamp to operate at full intensity.

Abstract: A lamp ballast includes an inverter circuit, a resonant circuit, a control circuit, and a startup circuit. When the DC bus reaches its final value, a capacitor in the startup circuit charges to a predetermined voltage, at which point a pulse is sent to start a gate drive circuit in the inverter. Additionally, a gate in the control circuit is initially OFF, allowing full power to the lamp, and a capacitor in the control circuit charges to a predetermined voltage, at which point a gate is turned ON. When the gate is ON, power to the lamp is reduced. The control circuit capacitor is selected so that it charges for a sufficient period to allow the lamp to complete a glow phase of startup before turning on the gate and reducing power as the lamp transitions into an arc phase.

Abstract: A pre-programmed energy saving ballast or driver is presented, having a pre-defined energy profile to which the output power is controlled in accordance with the current time ascertained from the input power connection via simplex clock information or from received broadcast time signals, and which allows a user to select from a number of pre-programmed profiles and/or to modify and store user-defined energy profiles.

Abstract: A ballast with self-oscillating inverter and a high-voltage multiplier circuit is disclosed for providing a DC start mechanism for starting an HID lamp. The high voltage multiplier ignites the lamp using direct current (DC) voltage. This results in low component stresses and lower output voltages than can be realized either by pulse starting or resonant starting techniques. DC starting reduces an output voltage required to start the HID lamp, and can be applied continuously without damaging the inverter. Moreover, the inverter, in self-oscillating mode, is compact while able to operate the HID lamp at frequencies well in excess of 1 MHz. The self-oscillating inverter can also be employed to regulate lamp power.

Abstract: A lamp ballast includes an inverter circuit, a resonant circuit, a control circuit, and a startup circuit. When the DC bus reaches its final value, a capacitor in the startup circuit charges to a predetermined voltage, at which point a pulse is sent to start a gate drive circuit in the inverter. Additionally, a gate in the control circuit is initially OFF, allowing full power to the lamp, and a capacitor in the control circuit charges to a predetermined voltage, at which point a gate is turned ON. When the gate is ON, power to the lamp is reduced. The control circuit capacitor is selected so that it charges for a sufficient period to allow the lamp to complete a glow phase of startup before turning on the gate and reducing power as the lamp transitions into an arc phase.

Abstract: A ballast circuit that facilitates providing thermal protection for a fluorescent lamp includes a coupling transformer that couples an inverter circuit to a control circuit. First and second transformer windings in the inverter circuit, and a third transformer winding in the control circuit, are wound around a common ferrite core. The ferrite core has a Curie temperature that approximates a maximum allowable threshold temperature for the lamp. When the temperature of the ballast approaches the Curie temperature of the ferrite core, its permeability, and thus inductance, drops dramatically, causing an increase in operating frequency in the inverter circuit. This increased operating frequency causes a capacitor in the control circuit to charge to a threshold voltage, at which power to the inverter circuit is reduced. The lamp then dims without turning off until the temperature is reduced to an acceptable level.

Abstract: A risk of shock (ROS) protection circuit is disclosed, which comprises a capacitor that charges whenever there is a voltage between a ground on a lamp ballast and earth ground. If the capacitor exceeds a predetermined threshold voltage, the capacitor causes a gate to shunt current away from a tertiary winding in a control circuit, which in turn reduces impedance reflected by the tertiary winding back on to primary and secondary windings in the ballast circuit. The reduced reflected impedance causes the operating frequency of the ballast to increase, reducing the voltage between the ballast ground and earth ground until it is safe for human contact. In this manner, a human replacing a lamp connected to the ballast can be protected from shock despite a failure to disconnect the power to the lamp ballast prior to lamp replacement.

Abstract: A ballast circuit including a charge pump interface circuit is disclosed to provide a method of isolating a switch from a power line used to power a ballast for supplying electrical power to a lamp. In addition, the charge pump interface circuit provides a method to control a discrete dimming ballast circuit which includes one or more inverters. The charge pump interface circuit offers cost advantages because no relays are necessary for isolation of the switch from the lamp electrical power and the dimming ballast circuit can be installed where existing lamps are currently mounted, without the need to add additional wiring.