The circuitry of an electronic mosquito swatter mainly consists of a high-frequency oscillation circuit, a step-up transformer, and a voltage multiplier rectifier circuit. After pressing the power switch, the oscillation circuit converts the low DC voltage provided by the battery into high-frequency AC power. This is initially boosted to several hundred volts by the transformer, and then further boosted to a high-voltage DC voltage of 1500V-4200V by the voltage multiplier rectifier circuit composed of diodes and capacitors, and then applied to the metal mesh grid.
Most products use a three-layer metal mesh structure. The outer two layers of metal mesh are of the same polarity, and the middle layer is of the opposite polarity. When insects such as mosquitoes and flies simultaneously come into contact with the outer and middle layers of the mesh, their bodies act as conductors, forming a short circuit, triggering a high-voltage discharge, and they are killed by the current and electric arc.
The safety of electric mosquito swatters is based on a "high voltage, low current" design. Their operating voltage can reach several thousand volts, but the output current is extremely small, typically between a few milliamps and tens of milliamps. Industry standard QB/T 4496-2013 stipulates that the working voltage of the high-voltage mesh of an electric mosquito swatter should be within the range of 2000V~4200V.
Under normal conditions, the outer mesh is not charged, and the product has the ability to eliminate residual electricity, reducing the inter-mesh voltage to a safe range within seconds after power is cut off. All samples were able to reduce the voltage to below the safe human voltage of 36V within 5 seconds of power being cut off.
Some high-end or newer models integrate a mosquito-attracting function. This works by utilizing the phototaxis of mosquitoes, emitting ultraviolet light of a specific wavelength to attract mosquitoes to the electric mesh.