Voltage output circuit, driving circuit and switching power supply

Abstract

The present invention discloses a voltage output circuit, a driving circuit and a switching power supply. The driving circuit is coupled to a light source, the driving circuit at least comprises a high-voltage output circuit and a pulse triggering circuit, the high-voltage output circuit comprises a transformer and at least one switch contact, the first input end of the transformer is connected with a power source voltage, the second input end of the transformer is connected with the pulse triggering circuit, the first output end of the transformer is connected with the first end of the at least one switch contact, the second output end of the transformer is connected with the second end of the at least one switch contact, the first end of the light source is connected with the second output end of the transformer, and the second end of the light source is coupled to the first output end of the transformer. When the light source is operated, the at least one switch contact is closed, and the working current of the light source flows through the at least one switch contact. Through the mode mentioned above, the loss can be reduced, the conversion efficiency can be improved, the size, the weight and the cost of the driving circuit can be reduced, the product miniaturization can be achieved, and the voice frequency noise problem caused by the transformer due to low-frequency commutation can be solved.

Description

Technical field [0001] This application relates to the technical field of switching power supplies, in particular to a voltage output circuit, a driving circuit, and a switching power supply. Background technique [0002] With the increasing shortage of power resources, the traditional light bulb electric lamp mode can no longer achieve the purpose of energy saving and emission reduction. In this case, HID lamps and other light sources are more and more widely used. HID lamp is an excellent light source with high efficiency and energy saving, but it has a defect, that is, it takes about 2-3 minutes to turn on the power under normal conditions to light up slowly. Sometimes when the power supply is restored immediately after a sudden power failure It takes 10-20 minutes to light up again, and it cannot light up at one point like incandescent lamps and halogen lamps. This is not suitable for occasions that require instantaneous lighting. [0003] In the long-term research and develop...

AI Technical Summary

Problems solved by technology

HID light is an excellent light source with high efficiency and energy saving, but it has a defect, that is, it takes about 2-3 minutes to turn on the power under normal circumstances before the light can slowly light up, sometimes when there is a sudden power failure and the power supply is restored immediately It takes 10-20 minutes to light up again, and it cannot be turned on at one point like incandescent lamps and halogen lamps, which is very unsuitable for occasions that require instant start lighting

[0003] The inventor of the present application found in the long-term research and development process that in the prior art, in order to increase the lighting speed of the HID lamp, the lighting circuit of the ballast is usually used, that is, the driving circuit, while the traditional low frequency (tens of Hz to hundreds of Hz) ) HID ballast drive circuits mostly use the pulse transformer start-up method, but this method has many disadvantages: 1) Due to the large number of turns of the high-voltage side winding of the pulse transformer, the loss is large and the conversion efficiency of the whole machine is low; 2 ) During the low-frequency commutation of the light source current, the pulse transformer will generate audio noise; 3) In order to improve the conversion efficiency or light source power, the high-voltage side winding of the pulse transformer needs to use thicker wires, which will increase the volume and weight of the transformer large, increased cost

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