Power-on impulse current suppression circuit of airborne display

Abstract

The embodiment of the invention provides a power-on impulse current suppression circuit of an airborne display. The circuit comprises a first thermistor (R1), a first P-channel MOSFET (Q1), a first PNP transistor (Q2), a second NPN transistor (Q3), a first capacitor (C1), a second capacitor (C2), a first resistor (R2), a second resistor (R3), a third resistor (R4), a fourth resistor (R5), and a fifth resistor (R6). The circuit provided by the invention can be suitable for all avionics equipment, and the circuit is connected in series between a power supply input and a filter capacitor / energy storage capacitor, so that the power-on impact current can be effectively suppressed, and the reliability and stability of the avionics equipment are improved.

Description

technical field [0001] The present disclosure relates to the technical field of avionics equipment, in particular to a power-on surge current suppression circuit for an airborne display. Background technique [0002] In the field of avionics, avionics equipment draws power from the aircraft power system. For the aircraft power system, it is an electrical device. Most avionics equipment is designed with a filter circuit. Generally, a large-capacity capacitor or energy storage is designed at the power input end. capacitance. At present, all airborne displays have a power-down hold function, so there will be a large internal energy storage capacitor during product design to meet the power-down hold function of the display. Since the voltage of the capacitor at the front end of power-on is zero, the impedance of the power input circuit Low, the capacitor is charged at the moment of power-on, the charging current is very large, and a large surge current is generated. Excessive ...

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Problems solved by technology

At present, there is no very effective method to solve the problem of suppressing the power-on surge current: traditional series fixed resistors, thermistors and other methods have defects, for example, they cannot solve the contradiction between suppressing the peak value of the current and the normal steady-state value , can not solve the problem of excessive power dissipation of the current-limiting resistor and excessive voltage drop of the current-limiting resistor during steady-state operation: in particular, it cannot accurately suppress the peak value of the surge current, making the circuit work uncertain

Another traditional method is to use resistance current limiting and time-delay short-circuit resistance. This method cannot judge the charging state of the subsequent load capacitor. Simply forcing the short-circuit resistance after a delay may still cause a large surge current and cause It will cause damage to the electric shock of the switch, and it cannot adapt to capacitive loads of different sizes and capacities

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