Led lamp arrangement

Abstract

An LED lamp arrangement for replacing a fluorescent lamp in a luminaire having a ballast. The LED lamp arrangement has at least a first group of LEDs and a second group of LEDs, a first circuit adapted to generate an output indicating whether the ballast is a magnetic ballast or a non-magnetic ballast, and a second circuit adapted to change a connection of the first and second groups of LEDs on the basis of the output of the first circuit. The second circuit is adapted to connect the first and second groups of LEDs in series, if the output from the first circuit indicates the ballast is a magnetic ballast, and to connect the first and second groups of LEDs in parallel, if the output from the first circuit indicates the ballast is a non-magnetic ballast.

What is claimed is: 
     
         1 . An LED lamp arrangement adapted to replace a fluorescent lamp in a luminaire having a ballast, the LED lamp arrangement comprising:
 at least a first group of LEDs and a second group of LEDs;   a first circuit adapted to generate an output indicating whether the ballast is a magnetic ballast or a non-magnetic ballast; and   a second circuit adapted to change a connection of the first and second groups of LEDs on the basis of the output of the first circuit, and   wherein the second circuit is adapted to connect the first and second groups of LEDs in series, if the output from the first circuit indicates the ballast is a magnetic ballast, and   wherein the second circuit is adapted to connect the first and second groups of LEDs in parallel, if the output from the first circuit indicates the ballast is a non-magnetic ballast.   
     
     
         2 . The LED lamp arrangement according to  claim 1 , wherein, in operation, the LED lamp arrangement is adapted to generate a substantially equivalent power output irrespective of whether the first and second groups of LEDs are connected in series or in parallel. 
     
     
         3 . The LED lamp arrangement according to  claim 1 , wherein the first circuit is configured to sense a frequency of power supplied to the LED lamp arrangement by the luminaire, and the second circuit is configured to connect the first and second groups of LEDs in series if the sensed frequency is within a first predetermined frequency range, and to connect the first and second groups of LEDs in parallel if the sensed frequency is within a second predetermined frequency range different from the first predetermined frequency range. 
     
     
         4 . The LED lamp arrangement according to  claim 1 , wherein the first circuit comprises at least one of:
 a sensing circuit adapted to sense a frequency of power supplied to the LED lamp arrangement, the first circuit generating the output indicating whether the ballast is a magnetic ballast or a non-magnetic ballast on the basis of the sensed frequency;   a sensing circuit adapted to sense harmonic content of voltage or current supplied to the LED lamp arrangement, the first circuit generating the output indicating whether the ballast is a magnetic ballast or a non-magnetic ballast on the basis of the sensed harmonic content; and   a sensing circuit adapted to sense an amplitude of current or voltage supplied to the LED lamp arrangement, the first and second circuit cooperating to sense the current or voltage when the first and second groups of LEDs are connected in series or in parallel, wherein the first circuit generates the output indicating whether the ballast is a magnetic ballast or a non-magnetic ballast on the basis of the sensed amplitude.   
     
     
         5 . The LED lamp arrangement according to  claim 1 , further comprising:
 a third circuit for sensing a condition indicating that current through a series connection of the first and second groups of LEDs is below a threshold, and generating an output; and   a fourth circuit adapted to short one of the first and second groups of LEDs in response to the output of the third circuit.   
     
     
         6 . An LED lamp arrangement adapted to replace a fluorescent lamp in a luminaire having a ballast for driving the LED lamp, the LED lamp arrangement comprising:
 a plurality of LEDs arranged in a plurality of groups, wherein the groups of LEDs are connectable in a plurality of circuit configurations,   wherein, in each of the circuit configurations, at least a portion of the groups of LEDs are connected into the circuit differently than in other ones of the plurality of circuit configurations, and   wherein the LED lamp arrangement is configured to change from one of the circuit configurations of the LEDs to another one of the circuit configurations of the LEDs, such that the LED lamp arrangement operates at a lower voltage when the ballast is an electronic ballast which has a characteristic of a constant current source, and operates at a higher voltage when the ballast is another type of ballast which does not have a characteristic of a constant current source.   
     
     
         7 . The LED lamp arrangement according to  claim 6 , wherein the LED lamp arrangement is configured to change from one of the circuit configurations of the LEDs to another one of the circuit configurations of the LEDs, in dependence on a threshold of a current through at least a portion of the plurality of LEDs. 
     
     
         8 . The LED lamp arrangement according to  claim 6 , wherein the characteristic of a constant current source comprises an approximately linear increase in power supplied by the ballast as output voltage from the ballast is increased, within a range of the output voltage. 
     
     
         9 . The LED lamp arrangement according to  claim 6 , wherein the LED lamp arrangement is configured to operate in a first operation mode at the higher voltage with a magnetic ballast and in a second operation mode at the lower voltage with the electronic ballast which has the characteristic of a constant current source, wherein the arrangement is configured to generate a substantially equivalent power output of the plurality of LEDs in the first and second operation modes. 
     
     
         10 . The LED lamp arrangement according to  claim 6 , wherein the LED lamp arrangement is configured to sense a frequency of power supplied to the LED lamp arrangement by the luminaire, and is configured to switch the plurality of groups of LEDs to a first circuit configuration if the sensed frequency is within a first predetermined frequency range, and to switch the plurality of groups of LEDs to a second circuit configuration if the sensed frequency is within a second predetermined frequency range different from the first predetermined frequency range. 
     
     
         11 . An LED lamp arrangement adapted to replace a fluorescent lamp in a luminaire having a magnetic ballast and in a luminaire having an electronic ballast, the LED lamp arrangement comprising:
 a plurality of LEDs arranged in a plurality of groups, wherein the groups of LEDs are connectable in a plurality of circuit configurations, including at least a first circuit configuration, and a second circuit configuration having a different circuit arrangement of the groups of LEDs in which at least a portion of the groups of LEDs are connected into the circuit differently than in the first circuit configuration;   a first circuit adapted to generate an output indicating whether the ballast is a magnetic ballast or an electronic ballast; and   a second circuit adapted to change a connection of the plurality of groups of LEDs from the first circuit configuration to the second circuit configuration on the basis of the output of the first circuit,   wherein the first circuit configuration comprises a greater number of the groups of LEDs connected in a series string than the second circuit configuration, and   wherein the second circuit is adapted to connect the plurality of groups of LEDs into the first circuit configuration when the output from the first circuit indicates the ballast is a magnetic ballast.   
     
     
         12 . The LED lamp arrangement according to  claim 11 , wherein the first circuit comprises a sensing circuit adapted to sense a frequency of power supplied to the LED lamp arrangement by the luminaire, and the second circuit is configured to switch the plurality of groups of LEDs to the first circuit configuration if the sensed frequency is within a first predetermined frequency range, and to switch the plurality of groups of LEDs to the second circuit configuration if the sensed frequency is within a second predetermined frequency range different from the first predetermined frequency range. 
     
     
         13 . The LED lamp arrangement according to  claim 12 , wherein the first predetermined frequency range corresponds to a frequency range output from a magnetic ballast and the second predetermined frequency range corresponds to a frequency range output from an electronic ballast, wherein the sensing circuit comprises a filter adapted to discriminate between a frequency range output from a magnetic ballast or an electronic ballast. 
     
     
         14 . The LED lamp arrangement according to  claim 11 , wherein the plurality of LEDs and the first and second circuits are arranged in a single housing in a configuration suitable to replace a fluorescent lamp in a luminaire. 
     
     
         15 . The LED lamp arrangement according to  claim 11 , wherein, in operation, the LED lamp arrangement is adapted to generate a power output of the plurality of groups of LEDs in the first circuit configuration used with one of a magnetic or electronic ballast which is substantially equivalent to a power output of the plurality of groups of LEDs in the second circuit configuration used with the other of a magnetic or electronic ballast. 
     
     
         16 . The LED lamp arrangement according to  claim 11 , further comprising:
 a third circuit for sensing a condition indicating whether current through at least a portion of the plurality of LEDs exceeds a threshold, and generating an output in dependence on the sensed condition; and   a fourth circuit adapted to change a connection of the plurality of groups of LEDs of the LED lamp arrangement between the first circuit configuration and the second circuit configuration on the basis of the output of the third circuit.   
     
     
         17 . The LED lamp arrangement according to  claim 16 , wherein the fourth circuit for switching the circuit configuration is adapted to switch between the first circuit configuration and another circuit configuration, or between the second circuit configuration and another circuit configuration, at a duty cycle. 
     
     
         18 . The LED lamp arrangement according to  claim 16 , wherein the fourth circuit for switching the circuit configuration is adapted to switch between the circuit configurations at a duty cycle which is determined at least in part on the basis of the output of the first circuit for sensing frequency. 
     
     
         19 . The LED lamp arrangement according to  claim 11 , further comprising:
 a fifth circuit for sensing a condition indicating that current through at least a portion of the plurality of LEDs is above a first threshold or below a second threshold; and   an energy storage circuit for storing at least part of electrical energy provided to the LED lamp arrangement;   wherein the energy storage circuit is adapted to store additional energy when the output of the fifth circuit indicates that current through at least a portion of the plurality of LEDs is above the first threshold, and to release previously stored energy when the output of the fifth circuit indicates that current through at least a portion of the plurality of LEDs is below the second threshold.   
     
     
         20 . The LED lamp arrangement according to  claim 11 , further comprising:
 a sixth circuit for sensing a frequency of power supplied to the LED lamp arrangement by the luminaire, and generating an output, and   a variable impedance connected across two input power connection lines of the LED lamp arrangement, the variable impedance providing an impedance which varies in accordance with the output of the sixth circuit for sensing a frequency.