A light guide plate driving circuit based on pwm dimming

Abstract

The invention relates to a PWM (pulse-width modulation) dimming based light guide plate driving circuit. The PWM dimming based light guide plate driving circuit mainly comprises a PWM signal input end, a PWM signal output end, a light guide plate dimming power circuit and a waveform adjusting circuit. The light guide plate dimming power circuit is used for changing a duty ratio of an input signal received from the PWM signal input end to form an output signal which is outputted through the PWM signal output end. The PWM dimming based light guide plate driving circuit has the advantages that a novel light guide plate dimming driving mode is provided, dimming is realized by adjusting the PWM duty ratio, and the problem of slight brightness of LEDs (light emitting diodes) in a light guide plate when the LEDs are off is well solved while the protection problem of influences of inductive load and capacitive load on circuits is solved as well.

Description

technical field [0001] The invention relates to a light guide plate in an airborne device, in particular to a light guide plate driving circuit based on PWM dimming. Background technique [0002] Light guide plate is an indispensable lighting element in airborne equipment, mainly used for character lighting and information display. With the development of the aviation industry today, higher and higher requirements are put forward for airborne equipment. The design of the light guide plate drive needs to consider the redundancy design of the extreme environment. The applicant found that in a high temperature environment, when the light guide plate works under standard conditions The rated current cannot satisfy its operation in high temperature environment, so when designing the drive circuit, it is necessary to amplify the rated current by 3-4 times to design. However, ordinary small-package triodes can no longer meet the design of large currents. The triode is a current-dr...

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Problems solved by technology

However, ordinary small-package triodes can no longer meet the design of large currents. The triode is a current-driven electrical component, and the MOS tube is a voltage-driven electrical component. Its input impedance is high, the required static driving power is small, and the package is small and the current is large. However, due to the parasitic capacitance between the poles, the drive circuit must be able to quickly charge / discharge its parasitic capacitance during turn-on and turn-off, especially in high-frequency applications

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