EMI filter and lightning protection circuit for DC28V power signal

Abstract

The invention provides an EMI (Electro-Magnetic Interference) filter and lightning protection circuit for a DC28V power signal, belongs to the technical field of aviation and electrics, and specifically relates to a DC28V power signal processing protection circuit applied to airborne equipment with electromagnetic compatibility and lightning protection demands. According to the circuit, an EMI filter circuit is built through a filter capacitor, a common mode inductor and other devices, so as to meet the requirements of a product for suppressing conduction-type common mode and differential modenoise in a DC28V power supply signal. The filter circuit can select inductance parameters according to the power of airborne equipment, and the capacitance parameters are calculated through the LC filter frequency. Based on the above, a transient suppression diode is matched to carry out lightning protection design. Compared with a piezoresistor, a transient suppression diode is smaller in leakage current and faster in response speed, and the protection circuit is integrated into an aviation electric connector, so that secondary signal interference caused by connection of wires in a product can be prevented. Through large-area contact between an electric connector metal shell and an airborne equipment shell, the filtering effect can be greatly improved.

Description

Technical field [0001] The invention belongs to the technical field of aeronautics and relates to a circuit for EMI filtering and lightning protection for DC28V power supply signals. Background technique [0002] In the past, airborne equipment had fewer requirements for lightning protection. The existing lightning protection products also designed all signals in a unified manner. The realization of independent circuit modules would take up more space. In order to improve the EMI conduction filtering effect of the product, it is often necessary to design the filter circuit in After the power supply enters the forefront of the product, a unified lightning protection circuit design cannot achieve the optimal matching of power signal EMI conduction filtering and lightning protection. [0003] The transient suppression diode is a voltage sensitive device. When its two poles are impacted by transient high energy, it can change the high impedance between the two poles into a low impedanc...

AI Technical Summary

Problems solved by technology

[0002] In the past, there were few requirements for lightning protection of airborne equipment, and the existing lightning protection products also have unified design for all signals, which requires more space to be implemented by independent circuit modules. In order to improve the EMI conduction filtering effect of products, it is often necessary to design the filter circuit After the power supply enters the front end of the product, the unified lightning protection circuit design cannot achieve the optimal match between power signal EMI conduction filtering and lightning protection

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