Method and system for reducing flickering-of lamps powered by an electricity distribution network

1 . A method for maintaining a desired stable light intensity of a plurality of lights to reduce flickering of lamps, the method comprising executing an automatic switching sequence to alter an AC power supply powering at least two independent segments of lamps, each electrically connected to a switching device, wherein the switching sequence comprising, for each half cycle of the AC power source,

maintaining open each of the switches connected to the segments of the lamps after a zero crossing of the AC cycle;

closing the switch of the first segment to turn on the lamps of the first segment;

waiting for at least one microsecond;

closing the switch of the second segment after a delay to turn on the lamps of the second segment;

opening the switch of the first segment to turn off the lamps of the first segment when the lamps of the first segment reach the desired light intensity; and

opening the switch of the second segment to turn off the lamps of the second segment when the lamps of the second segment reach the desired light intensity.

2 . The method of claim 1 , wherein the waiting corresponding to a time to recover a loss of voltage caused the lamps of one of the segments being turned on.

3 . The method of claim 1 , wherein the segments comprising more than two segments, the closing of the switches of the segments being triggered in sequence and with a delay following the closing of the switch of another segment.

4 . The method of claim 3 , wherein the delay following the closing of the switch of the other segment being 1 micro second.

5 . The method of claim 1 , wherein the delay being randomly changed after one or more half cycle of the AC power supply.

6 . The method of claim 1 , wherein further comprising adjusting a conduction period of the lamps based on a turn-on angle of the AC power signal for producing the desired light intensity of the lamps to automatize equalization of the lighting intensity of the lamps between the at least two segments.

7 . The method of claim 6 , wherein further comprising using a transfer function to establish the duration of the conduction period according to the desired lighting intensity and to a firing angle of one of the at least two segments of lamps.

8 . The method of claim 7 , wherein further comprising using a characteristic curve of the intensity transmitted by the lamps of the segments according to switching angle and to duration of conduction for the light intensity of the lamps is a function of the switching angles.

9 . A method for maintaining a desired stable light intensity of a plurality of lights to reduce flickering of lamps, the method comprising executing an automatic switching sequence to alter an alternative current (AC) power supply powering at least two independent segments of lamps at the desired light intensity, each of the segments of lamps being electrically connected to a switching device, wherein the switching sequence comprising, for each half cycle of the AC power source,

maintaining open each of the switches connected to the segments of the lamps after a zero crossing of the AC cycle;

closing the switch of the first segment when the voltage is above the lamps turn-on threshold defining a first conduction angle to turn on the lamps of the first segment;

opening the switch of the first segment when the desired light intensity of the first segment is reached defining a second conduction angle to turn off the lamps of the first segment;

closing the switch of the second segment when a conduction angle of the AC of the second segment is a supplement of the second conduction angle to turn on the lamps of the second segment; and

opening the switch of the second segment when a conduction angle is a supplement of the first conduction angle.

10 . A lighting system maintaining a stable light intensity and reducing the in-rush current of the lighting system, the system comprising:

two paired segments powered by alternative current (AC), each AC half-cycle having a duration P hcycle , each segment comprising:

a plurality of lamps;

an electronic switch connected to the segment;

wherein a switching sequence of the electronic switch starts at a zero-crossing point T 0 of the AC voltage, the electronic switch being open at T 0 ;

the switching sequence of the electronic switch connected to the first segment comprising:

a. closing the electronic switch to turn on the first segment of the lamps at a time from T 0 for a conduction period of P on ;

b. following the step a, opening the electronic switch to turn off the first segment of lamps at a time T 1off , the period P 1off being T 1off −T 0 ;

the switching sequence of the electronic switch connected to the second segment comprising:

c. closing the electronic switch to turn on a second of the two segments of the lamps at a time P hcycle −P 1off from T 0 for the conduction period of P on ;

d. following the step c, opening the electronic switch to turn off the second segment.

11 . The lighting system of claim 10 , comprising a plurality of paired segments, wherein activation of each of the paired segments is delayed between each activation.

12 . The lighting system of claim 11 , the delayed activation being selected to allow AC voltage disturbance caused by inrush current in one of the paired segments to subside before activating the next paired segments to reduce cumulative inrush current effects on waveform of the AC.

13 . The lighting system of claim 11 , wherein each of the paired segments has different switching angles, the lighting system being configured to vary the conduction duration of each of the paired segments to equalize the light intensity between the paired segments.

14 . The lighting system of claim 10 , wherein the closing of the electronic switch to supply power to the first segment being performed when the AC voltage exceeds the conduction threshold of the lamps in the first segment.