A kind of surge protection circuit and surge protection method

Abstract

The present invention provides a surge protection circuit and a surge protection method. The surge protection circuit may include: a first series circuit composed of at least two TVS connected in series, one end of the first series line is connected to a positive terminal, and the other One end is connected to a negative polarity terminal; at least one second series circuit consisting of at least one TSS, one end of the second series circuit is connected between at least two TVSs in the first series circuit, and the other end is grounded; the first series circuit is connected to the device The protected circuit is connected in parallel; using the first series line, when the differential mode surge voltage appears at both ends of the first series line, the voltage of the back-end connection circuit is clamped to the first voltage value; using the first series line and the The second series circuit reduces the ground voltage of the positive terminal and the negative terminal to a second voltage value when a common-mode surge voltage occurs between the two ends of the first series circuit and the ground terminal respectively. According to the solution, more effective surge protection can be provided.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a surge protection circuit and a surge protection method. Background technique [0002] In some power or signal circuits, surges often occur. Surges are caused by switching and lightning transient overvoltages. Surges may cause abnormal operation or even damage to equipment in the circuit. [0003] For industrial measurement and control equipment under normal use conditions, such as field instruments, the surge voltage that may be caused by the environment is relatively low. For example, the surge voltage required for industrial measurement and control equipment specified in IEC61326 is 1kV. In order to achieve surge protection, a filter circuit can be used to protect the equipment. When a surge voltage occurs, the filter circuit will filter the surge voltage to avoid excessive voltage of the protected circuit at the back end, thereby realizing surge protection. [0004] Thi...

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Problems solved by technology

[0004] This prior art generally takes measures when the surge is small, but in some environments, the surge voltage may increase, and a simple filter circuit cannot perform more effective surge protection

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