Abstract: The invention discloses a method for controlling the time sharing starting of electronic ballasts and a delayed-started electronic ballast. According to the method, the electronic ballasts are delayed-started after being energized, and delay time for the delayed starting of the electronic ballasts is a random number acquired based on the temperature of the ballasts. The delayed-started electronic ballast includes an electronic ballast body and a delay switch. After the adoption of the technical scheme of the invention, a delayer with the delay time set by virtue of random numbers corresponding to different environmental temperature is additionally arranged in the ballast, and multiple ballasts connected in parallel in a circuit can be started at different time points after different delay time under the control of the same control switch, which remarkably reduces current impact on a power grid and reduces a voltage drop condition.

Abstract: The invention provides a High Intensity Discharge (HID) lamp acoustic resonance suppression method. 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 ballast includes an acoustic resonance elimination module. The invention has the beneficial effects that due to the additional arrangement of the acoustic resonance elimination module, acoustic resonance is maximally suppressed, and the optimal stability of a discharge arc is ensured. These characteristics enable the product to stably run for each type of lamp tube and different power.