Abstract: For the purpose of reducing power and improving production capacity of plasma loudspeaker, based on
the theoretical analysis, we analyze the characteristics and principles of the two typical methods, ZVS(Zero
Voltage Switch) and PWM (Pulse-Width Modulation), combining the advantages of the two schemes, propose a
soft switch control method based on PWM pulse width modulation. The driving circuit adopts IR2110 chip to
enhance the driving ability of the circuit. The switch part adopts the soft switch method to improve the overall
efficiency of the circuit. By comparing the power input, the switching tube heating condition and the arc length,
it is found that the output power is 12 W when the arc length is 1. 5 cm, the surface temperature of the two
switches are 50℃ and 58℃. The experimental results show that the proposed scheme reduces the power
consumption, improves the stability and safety of the overall circuit, and reduces the distortion of the PWM wave
which controls the switch. Therefore, it has better practical application and product capability.

Key words: pulse-width modulation(PWM),  plasma loudspeaker, small power, soft switch, zero voltage switch(ZVS)