| 摘要 |
An apparatus and method to implement an electronic ballast for a high intensity discharge lamp having AC lamp current centered at approximately 300 kHz minimizes the ballast cost and utilizes modulation of the lamp current to avoid acoustic resonance. In order to minimize the number of additional components providing the modulation function, the ripple voltage produced by PFC circuit is fed through a capacitor to a FREQUENCY SET input of an inverter controller. The value of the capacitor can be chosen to produce the desired modulation range.
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