TDK Corporation (TSE:6762) presents two new varistor series in SMD design. The types of both series are available for a wide range of operating voltages from 175 VRMS to 460 VRMS, corresponding to 225 VDC to 615 VDC. While the B72210M* series of surge devices, which are equivalent to S14 leaded disk varistors, offers a surge current capability of 6000 A, the B72214M* series types, which are equivalent to S20 leaded disk varistors, have a high surge current capability of 10,000 A. All types are designed for a high operating temperature of a maximum of +125 °C and extremely damp heat environment (85% relative humidity at +85 °C).

Find the optimal voltage protection devices based on maximum surge currents, maximum continuous voltages, and applications.

Varistors can be used as suppressors to protect devices and circuits from transient abnormal voltages including an ESD (electrostatic discharge) and a lightning surge. For protection from a relatively large surge current (100A to 25kA), leaded disk varistors and SMD disk varistors are suitable. For protection from a larger surge current (approximately 25kA or more), block varistors, and strap varistors are suitable.
This article describes surge protection device applications for LED lighting system, inductive loads such as motors, motor with an electromagnetic brake, SSR (solid-state relay), load dump and field decay, joint boxes and power conditioners of solar power generation systems, important devices using a lightning transformer, and high-energy surge in industrial devices.