Two-transistor flyback single-stage PFC LED circuit

Abstract

The invention discloses a two-transistor flyback single-stage PFC LED circuit, which comprises a VCC power supply circuit, a two-transistor flyback circuit and a chip IC1. A triode Q3 is electrically connected with the output end of the VCC power supply circuit; a diode D4 is connected in parallel with the MOS triode Q3 and a capacitor C8; the MOS triode Q3 is connected in series with a MOS triode Q4 through a capacitor C18; the capacitor C18 is connected to a first primary side of a transformer T1; a secondary side of the transformer T1 is connected with a diode DS7, a diode DS6, a capacitor SC11, a resistor RS1 and a resistor RS2; an N channel of the MOS triode Q3 is connected to a resistor R22 and a resistor R6; and pins of the chip IC1 are output to a totem circuit through a resistor R17. The two-transistor flyback single-stage PFC LED circuit is simple in circuit structure; MOS withstand voltage is small, and RDS is small; loss is low; efficiency is high; energy is saved; the service life of the product is prolonged; cost is low and reduced; and one high-withstand voltage MOS is far better than two low-voltage MOS.

Description

technical field [0001] The invention belongs to the technical field of LED power supplies, and in particular relates to a dual-tube flyback single-stage PFC LED circuit, which is specifically applied to LED power supplies with higher AC input voltage, higher PF and low THD requirements. Background technique [0002] The existing LED power supply technology applications are either input voltage below 305V, or a higher input voltage is achieved through a dual-stage PFC circuit. From the cost of the whole machine, and the application selection of the device, to the efficiency of the whole machine, the power of the product Density is a relatively traditional technology, resulting in high cost of the whole machine, poor application selection of devices and low efficiency of the whole machine. The current double-tube single-stage PFC circuit can better solve the deficiencies of the prior art. Contents of the invention [0003] The purpose of the present invention is to provide ...

AI Technical Summary

Problems solved by technology

[0002] The existing LED power supply technology applications are either input voltage below 305V, or a higher input voltage is achieved through a dual-stage PFC circuit. From the cost of the whole machine, and the application selection of the device, to the efficiency of the whole machine, the power of the product Density is a relatively traditional technology, resulting in high cost of the whole machine, poor application selection of devices and low efficiency of the whole machine

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