Patent ID: 9635747
Date: 2017-04-25
CPC Classifications: B01J,H05B,Y02B

Claim:
1. A High Intensity Discharge (HID) lamp acoustic resonance suppression method, wherein whether acoustic resonance is produced or not is judged, and a frequency-modulated current frequency provided by a ballast when the acoustic resonance is produced to fulfill the aim of suppressing the acoustic resonance, the method comprising the following steps: A: performing in-phase detection on a current of a lamp tube, wherein an outgoing current and an incoming current of output lines of the ballast are simultaneously detected; B: judging whether the outgoing current and the incoming current, which are simultaneously detected, of the output lines of the ballast are inphase and equal or not, and if the outgoing current and the incoming current are inphase and equal, locking a current frequency-modulated current frequency provided by the ballast and ending the method, otherwise turning to Step C; and C: linearly changing the frequency-modulated current frequency provided by the ballast within a low-frequency range, and turning to Step A.