Alternating current voltage regulating device for projection lamp

Abstract

The invention discloses an alternating current voltage regulating device for a projection lamp. The alternating current voltage regulating device comprises a rectifying circuit, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first transistor, a second transistor, a phototriode, a unijunction transistor, a thyristor, a capacitor and a potentiometer. A transistor automatic alternating current voltage regulating circuit is adopted, so the first transistor, the second transistor and the phototriode play the function of equivalent resistors, when light rays of the projection lamp change along with the change of the power supply voltage, the resistance of the phototriode changes, the voltage phase controlling the unijunction transistor is changed, so that the pulse phases of the transistors move, the breakover time of the transistors is increased or decreased, and the voltage of a bulb of the projection lamp is enabled to approximately remain unchanged. The alternating current voltage regulating device adopts the transistor automatic alternating current voltage regulating circuit, enables the brightness of the bulb of the projection lamp to be relatively stable, can enable the brightness of the bulb to be stable under the condition that the voltage is instable, and further protects the bulb from being burnt.

Description

technical field [0001] The invention relates to an additional device for a projection lamp, in particular to an AC voltage regulating device for a projection lamp. Background technique [0002] At present, various projector projection lamps have been popularized. As we all know, the brightness of projection lamps must meet very high requirements to make the picture clearer. However, in the case of unstable voltage, the current projection lamps are likely to cause lights to flicker. Even burn out the projection lamp. Contents of the invention [0003] The object of the present invention is to provide an AC voltage regulating device for projection lamps in order to solve the above problems. [0004] The present invention achieves the above object through the following technical solutions: [0005] The invention includes a rectifier circuit, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first transistor, a second transistor, ...

AI Technical Summary

Problems solved by technology

[0002] At present, various projector projection lamps have been popularized. As we all know, the brightness of projection lamps must meet very high requirements to make the picture clearer. However, in the case of unstable voltage, the current projection lamps are likely to cause lights to flicker. Even burn out the projector lamp

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