Abstract: Multiple LEDs connected in series are driven by DC voltage that is provided by a diode rectifier connected to a three-phase power source. In order to reduce ripple in the DC voltage, the series-connected LEDs can be divided into a first set and a second set, and a first constant current source is provided that drives the first set, and a second constant current source is provided that drives the second set. The first and second constant current sources are both connected across the outputs of the rectifier circuit, and operate to drive the respective sets of light emitting diodes in alternation. The capability for dimming can be provided, as well as back-up single phase operation. The light emitting diodes can be situated remote from said rectifier and connected thereto by a single phase power transmission system, formed by only two wires.

Abstract: Multiple LEDs connected in series are driven by DC voltage that is provided by a diode rectifier, the diode rectifier being connected to a three-phase power source and converting the three-phase currents from the three-phase power source into the DC voltage that is used to drive the light emitting diodes. In order to reduce ripple in the DC voltage, the series-connected light emitting diodes can be divided into a first set and a second set, and a first constant current source is provided that drives the first set, and a second constant current source is provided that drives the second set. The first and second constant current sources are both connected across the outputs of the rectifier circuit, and operate to drive the respective sets of light emitting diodes in alternation. The capability for dimming can be provided, as well as back-up single phase operation.

Abstract: An LED array switching apparatus comprises, on a single PCB substrate: a plurality of LED arrays D1 to Dn connected in series, each LED array having a forward voltage; an AC voltage supply coupled to the plurality of LED arrays; and a plurality of constant current sources G1 to Gn, coupled to outputs of LED arrays D1 to Dn, respectively, each of the constant current sources being switchable between a current regulating state and an open state such that as the voltage of the AC voltage supply increases, LED arrays are switched on and lit to form a higher forward voltage LED string, and as the voltage of the AC voltage supply decreases, LED arrays are switched off and removed from the LED string starting with the most recently lit LED array.

Abstract: Multiple LEDs connected in series are driven by DC voltage that is provided by a diode rectifier connected to a three-phase power source. In order to reduce ripple in the DC voltage, the series-connected LEDs can be divided into a first set and a second set, and a first constant current source is provided that drives the first set, and a second constant current source is provided that drives the second set. The first and second constant current sources are both connected across the outputs of the rectifier circuit, and operate to drive the respective sets of light emitting diodes in alternation. The capability for dimming can be provided, as well as back-up single phase operation. The light emitting diodes can be situated remote from said rectifier and connected thereto by a single phase power transmission system, formed by only two wires.

Abstract: Multiple LEDs connected in series are driven by DC voltage that is provided by a diode rectifier, the diode rectifier being connected to a three-phase power source and converting the three-phase currents from the three-phase power source into the DC voltage that is used to drive the light emitting diodes. In order to reduce ripple in the DC voltage, the series-connected light emitting diodes can be divided into a first set and a second set, and a first constant current source is provided that drives the first set, and a second constant current source is provided that drives the second set. The first and second constant current sources are both connected across the outputs of the rectifier circuit, and operate to drive the respective sets of light emitting diodes in alternation. The capability for dimming can be provided, as well as back-up single phase operation.

Abstract: An LED array switching apparatus comprises, on a single PCB substrate: a plurality of LED arrays D1 to Dn connected in series, each LED array having a forward voltage; an AC voltage supply coupled to the plurality of LED arrays; and a plurality of constant current sources G1 to Gn, coupled to outputs of LED arrays D1 to Dn, respectively, each of the constant current sources being switchable between a current regulating state and an open state such that as the voltage of the AC voltage supply increases, LED arrays are switched on and lit to form a higher forward voltage LED string, and as the voltage of the AC voltage supply decreases, LED arrays are switched off and removed from the LED string starting with the most recently lit LED array.

Abstract: An LED lighting circuit where the configuration of the connection of two or more LEDs are changed from parallel to series through the use of solid state switches depending on whether the voltage level from an AC source measured by a voltage detector exceeds the sum of the forward voltages of the LEDs. Also, a method of activating LEDs in an LED array lighting apparatus involving applying a rectified alternating current to two or more LEDs, each LED having a forward bias voltage; comparing the rectified alternating current to the sum of the forward bias voltages of the two or more LEDs; and changing the circuit configuration of the two or more LEDs between a parallel connection and a series connection with respect to the rectified alternating current depending on whether the rectified alternating current exceeds the sum of the forward bias voltages of the two or more LEDs.

Abstract: A device and method for reducing current ripple to a light emitting diode array having a single stage power factor correction driver with an output voltage ripple that is reduced by using a linear current regulator connected in series between the single stage power factor correction driver and the light emitting diode array, which actively adjusts an equivalent impedance of the linear current regulator in correspondence with the output voltage ripple of the single stage power factor correction driver.

Abstract: An LED lighting circuit where the configuration of the connection of two or more LEDs are changed from parallel to series through the use of solid state switches depending on whether the voltage level from an AC source measured by a voltage detector exceeds the sum of the forward voltages of the LEDs. Also, a method of activating LEDs in an LED array lighting apparatus involving applying a rectified alternating current to two or more LEDs, each LED having a forward bias voltage; comparing the rectified alternating current to the sum of the forward bias voltages of the two or more LEDs; and changing the circuit configuration of the two or more LEDs between a parallel connection and a series connection with respect to the rectified alternating current depending on whether the rectified alternating current exceeds the sum of the forward bias voltages of the two or more LEDs.

Abstract: A device and method for reducing current ripple to a light emitting diode array having a single stage power factor correction driver with an output voltage ripple that is reduced by using a linear current regulator connected in series between the single stage power factor correction driver and the light emitting diode array, which actively adjusts an equivalent impedance of the linear current regulator in correspondence with the output voltage ripple of the single stage power factor correction driver.

Abstract: A circuit for driving a light emitting diode (LED) comprises: an alternating voltage power supply, comprising a triac dimmer having a firing angle and output terminals that provide power to the LED: a zero crossing detector that detects a polarity change of the alternating voltage provided by the alternating voltage power supply and provides a zero crossing output signal indicative of the zero crossing; a timer triggered by the zero crossing output signal that generates a timer output signal, during a time period of the timer; and LED power circuitry that reduces current to the light emitting diode based upon timing characteristics of the timer output signal.

Abstract: An LED light bulb has a lamp base for a lamp socket, a heat sink, and a globe. Within the globe on the heat sink is a printed circuit board having tabs or legs projecting from the circuit board. The tabs or legs have one or more LEDs mounted thereon and are angled relative to the circuit board so as to be directed away from the axis of the light bulb. the circuit board may either be ring-shaped with inwardly extending tabs, or may have outwardly extending tabs. Methods of making such LED light bulb and methods of distributing light from the LED light bulb, which involves directing light output by a plurality of LEDs in a plurality of radially outward directions relative to an axis of the light bulb, are also disclosed herein.

Abstract: A lossless LED forward voltage matching network connected between an AC source and a driver of an LED array, where the LED array is series connected and sequentially activates as the output voltage of the LED driver exceeds the respective forward voltages of the LED arrays. The matching network reduces the voltage from the AC source to approximate the total of the forward voltages of the series connected LED arrays to increase the efficiency of the device.

Abstract: A circuit for driving a light emitting diode (LED) comprises: an alternating voltage power supply, comprising a triac dimmer having a firing angle and output terminals that provide power to the LED; a zero crossing detector that detects a polarity change of the alternating voltage provided by the alternating voltage power supply and provides a zero crossing output signal indicative of the zero crossing; a timer triggered by the zero crossing output signal that generates a timer output signal during a time period of the timer; and LED power circuitry that reduces current to the light emitting diode based upon timing characteristics of the timer output signal.

Abstract: A power-factor-corrected power supply adapted to supply power to one or more light emitting diodes (LEDs), comprises: a triac dimmer electrically connected between an alternating current source and a bridge rectifier; a damping circuit electrically connected between the alternating current source and the bridge rectifier; a bleeder circuit configured to conduct current between a supply terminal of the bridge rectifier and ground only when a triac in the triac dimmer is not conducting current; a fast startup circuit configured to conduct current between the supply terminal of the bridge rectifier and a voltage supply terminal of a power-factor-corrected controller when the triac dimmer is initially turned on until a supply voltage capacitor coupled to the voltage supply terminal of the power-factor-corrected controller has charged; a dimming slope control circuit configured to reduce a first voltage sensed at a current sensing terminal of the power-factor-corrected controller, such that a reduced amount of cur

Abstract: A power-factor-corrected power supply adapted to supply power to one or more light emitting diodes (LEDs), comprises: a triac dimmer electrically connected between an alternating current source and a bridge rectifier; a damping circuit electrically connected between the alternating current source and the bridge rectifier; a bleeder circuit configured to conduct current between a supply terminal of the bridge rectifier and ground only when a triac in the triac dimmer is not conducting current; a fast startup circuit configured to conduct current between the supply terminal of the bridge rectifier and a voltage supply terminal of a power-factor-corrected controller when the triac dimmer is initially turned on until a supply voltage capacitor coupled to the voltage supply terminal of the power-factor-corrected controller has charged; a dimming slope control circuit configured to reduce a first voltage sensed at a current sensing terminal of the power-factor-corrected controller, such that a reduced amount of cur

Abstract: An LED array switching apparatus comprises, on a single PCB substrate: a plurality of LED arrays D1 to Dn connected in series, each LED array having a forward voltage; an AC voltage supply coupled to the plurality of LED arrays; and a plurality of constant current sources G1 to Gn, coupled to outputs of LED arrays D1 to Dn, respectively, each of the constant current sources being switchable between a current regulating state and an open state such that as the voltage of the AC voltage supply increases, LED arrays are switched on and lit to form a higher forward voltage LED string, and as the voltage of the AC voltage supply decreases, LED arrays are switched off and removed from the LED string starting with the most recently lit LED array.

Abstract: A circuit for driving a light emitting diode (LED) comprises: an alternating voltage power supply, comprising a triac dimmer having a firing angle and output terminals that provide power to the LED; a zero crossing detector that detects a polarity change of the alternating voltage provided by the alternating voltage power supply and provides a zero crossing output signal indicative of the zero crossing; a timer triggered by the zero crossing output signal that generates a timer output signal during a time period of the timer; and LED power circuitry that reduces current to the light emitting diode based upon timing characteristics of the timer output signal.

Abstract: An electrical protection system, which can be connected between an electrical power supply and an electrical load, firstly includes a switch switchable between a normal state in which the switch is electrically connected in series between the power supply and the load such that an operating current passes through the switch and the load, and a fault sate in which the switch is disconnected with the load such that no current passes through the load. The switch switches to the fault state in an over-current or an over-temperature situation.

Abstract: An electrical protection system, which can be connected between an electrical power supply and an electrical load, firstly includes a switch switchable between a normal state in which the switch is electrically connected in series between the power supply and the load such that an operating current passes through the switch and the load, and a fault sate in which the switch is disconnected with the load such that no current passes through the load. The switch switches to the fault state in an over-current or an over-temperature situation.