Patent ID: 7781986

Claim:
An inverter with adjustable resonance gain, comprising: a PWM (Pulse Width Modulation) unit, a switch unit, a resonance unit, a transformer, a feedback unit, a dimming signal source, and a frequency control unit, wherein the inverter is connected to a power source for obtaining a DC power, the PWM unit produces a working cycle signal to drive the switch unit to convert the DC power into a pulse power, and the resonance unit converts the pulse power into a driving power, which is provided to the transformer for being converted into an output power, so as to drive a lamp tube set linked to the inverter, and wherein the dimming signal source produces a dimming signal, the feedback unit obtains a feedback signal from the secondary side of the transformer, and the frequency control unit, in accordance with the dimming signal and the feedback signal, decides a reference frequency signal for providing to the PWM unit to adjust the frequency of the working cycle signal, when the pulse power is under a starting frequency and a working frequency higher than the starting frequency, the resonance unit produces a starting voltage gain and a working voltage gain respectively corresponding to the starting frequency and the working frequency, wherein the starting voltage gain which is used to initiate the lamp tube set is larger than the working voltage gain.