Constant current class 3 lighting system
View Patent ↗A flexible cable is provided for a lighting system having a power supply that includes a power supply input to receive a first signal having a first frequency and a circuit for converting the first signal to a second signal, and at least one luminaire coupled to a lamp driver. The cable comprises a first leg of wires for carrying the second signal. The first wire electrically connects a loop output of the power supply to an input of the lamp driver and a second wire electrically connects an output of the lamp driver to a loop return of the power supply. The cable further comprises a second leg of wires electrically connected to a ground of the power supply and the ground of the lamp driver. The second signal has a substantially constant current and a second frequency distinctly higher than the first frequency. The flexible cable further comprises a modular connector.
1. A flexible cable for a lighting system having a power supply and at least one luminaire, the power supply including a power supply input to receive a first signal having a first frequency and a circuit for converting the first signal to a second signal, and the at least one luminaire coupled to a lamp driver, the cable comprising:
a first leg of wires for carrying the second signal having a first wire electrically connecting a loop output of the power supply to a loop input of the lamp driver and a second wire electrically connecting a loop output of the lamp driver to a loop return of the power supply; and
a second leg of wires electrically connected to a ground of the power supply and a ground of the lamp driver wherein,
the first wire and the second wire are insulated from one another, wherein the flexible cable further comprising a modular connector, and the second signal has substantially constant current and a second frequency of the second signal distinctly higher than the first frequency of the first signal.
2. The flexible cable of claim 1 , wherein the second leg of wires comprises at least one uninsulated wire.
3. The flexible cable of claim 1 , wherein the second frequency is approximately 48 kHz.
4. The flexible cable of claim 1 , wherein the substantially constant current is between about 0.67 Arms and about 3.3 Arms.
5. The flexible cable of claim 1 , wherein the substantially constant current is approximately 1.3 A rms.
6. The flexible cable of claim 1 , wherein the second signal has a power factor greater than 0.98.
7. The flexible cable of claim 1 , wherein the second signal has a bi-phase voltage.
8. The flexible cable of claim 2 , wherein the first leg of wires and the uninsulated wire are housed only in a flexible jacket between the power supply and the lamp driver.
9. The flexible cable of claim 2 , wherein the uninsulated wire is 14 AWG bare copper wire.
10. The flexible cable of claim 2 , wherein the twisted pair of wires has a capacitance of approximately 19 picofarads per foot.
11. The flexible cable of claim 8 , wherein the flexible jacket includes a narrow web portion to separate the first leg of wires from the uninsulated wire.
12. The flexible cable of claim 11 , wherein a insulation surrounding the first leg having non- polarized twisted pair of wires is comprised of Halar.
13. The flexible cable of claim 11 , wherein the narrow web portion has a thickness of approximately .018 inches nominal.
14. The flexible cable of claim 12 , wherein the twisted pair has about 1.27 twists or more per inch.
15. The flexible cable of claim 12 , wherein the insulation has a thickness of 0.01 inches nominal.
16. The flexible cable of claim 12 , wherein the twisted pair of wires is 18 AWG bare copper wire.
17. The flexible cable of claim 14 , wherein the insulation surrounding the first leg of wires is comprised of Halar.
18. The flexible cable of claim 14 , wherein the twisted pair has about 1.27 twists per inch or greater.
19. The flexible cable of claim 14 , wherein the twisted pair of wires is 18 AWG bare copper wire.
20. The flexible cable of claim 19 ,wherein the uninsulated wire is 14 AWG bare copper wire.