Shell-type transformers use an anti-ఉన్నట్లుండి coil with high dielectric strength to resist the influence of pulse వోల్టేజ్. Since shell-type transformers use coils with large surface area, the series capacitance between coils is large. When a ఉన్నట్లుండి is applied, it can Distributing the వోల్టేజ్ reasonably, the surge coil is a non-oscillating winding, which can suppress the voltage oscillation caused by the pulse voltage.