Anti-interference DC isolation circuit

Abstract

A DC isolation circuit used for preventing interference comprises an MOS tube Q1, a transformer TX and a rectification filter circuit, a DC voltage positive electrode Vin + is connected with a drain electrode of the MOS tube Q1, a grid electrode of the MOS tube Q1 is connected with a single-chip microcomputer, a source electrode of the MOS tube Q1 is connected with one end of a primary coil of the transformer TX, a DC voltage negative electrode Vin-is connected with the other end of the primary coil of the transformer TX through a resistor Rs, and the rectification filter circuit is connected with the single-chip microcomputer. And a secondary coil of the transformer TX outputs after passing through the rectification filter circuit. According to the principle of the utility model, a single-chip microcomputer controls a transformer TX through PWM signals, so that a primary coil of the transformer TX starts oscillation, and an oscillation circuit is formed; and the secondary coil of the transformer outputs isolated direct-current voltage through the rectifying and filtering circuit.

Description

Technical Field

[0001] The utility model relates to the technical field of isolation circuits, in particular to a DC isolation circuit for anti-interference used in audio equipment. Background Art

[0002] At present, many audio equipment have added functions such as lights, displays, motors, etc. Since functions such as lights, displays, motors, etc. share a set of power supply systems, it is very difficult to avoid mutual interference; especially for some battery-powered products, because they are DC, it is even more impossible to achieve isolation on the switching power supply for AC power supply. When the added devices work simultaneously, harsh noises often occur in the speakers, seriously affecting the normal use of the audio. Summary of the Invention

[0003] The technical problem to be solved by the utility model is to provide a DC isolation circuit for anti-interference, which uses a DC isolation circuit to avoid mutual interference between devices.

[0004] To solve the above technical problem, the technical solution of the utility model is: a DC isolation circuit for anti-interference, including MOS transistor Q1, transformer TX and a rectifying and filtering circuit. The positive pole Vin+ of the DC voltage is connected to the drain of MOS transistor Q1. The gate of MOS transistor Q1 is connected to the single-chip microcomputer. The source of MOS transistor Q1 is connected to one end of the primary coil of transformer TX. The negative pole Vin- of the DC voltage is connected to the other end of the primary coil of transformer TX through resistor Rs. The secondary coil of transformer TX outputs after passing through the rectifying and filtering circuit. The principle of the utility model: The single-chip microcomputer controls transformer TX through a PWM signal, causing the primary coil of transformer TX to oscillate, forming an oscillation circuit; the secondary coil of the transformer outputs an isolated DC voltage through the rectifying and filtering circuit.

[0005] As an improvement, a capacitor C1 is provided between the positive pole Vin+ and the negative pole Vin- of the DC voltage.

[0006] As an improvement, the rectifying and filtering circuit includes diode D1, diode D2, inductor L1 and capacitor C2. One end of the secondary coil of the transformer is connected to the positive pole of diode D1. The negative pole of diode D1 is connected to the input end of inductor L1. The output end of inductor L1 is connected to the output positive pole. The other end of the secondary coil of transformer TX is connected to the input end of inductor L1 through diode D2. The other end of the secondary coil of transformer TX is connected to the output end of inductor L1 through capacitor C2. The other end of the secondary coil of transformer TX is connected to the output negative pole through resistor R1.

[0007] The beneficial effect brought by the utility model compared with the prior art is:

[0008] When using a DC isolation circuit, can it be used regardless of whether the machine is equipped with a battery? Power supply for devices such as speakers, lights, and motors is independent to avoid mutual interference. Description of the Drawings

[0009] Figure 1 This is the circuit schematic diagram of the present utility model. Detailed Implementation Manner

[0010] The present utility model will be further described below in conjunction with the drawings in the specification.

[0011] As Figure 1 shown, a DC isolation circuit for anti-interference includes a MOS transistor Q1, a transformer TX, and a rectifying and filtering circuit; the positive pole Vin+ of the DC voltage is connected to the drain of the MOS transistor Q1, the gate of the MOS transistor Q1 is connected to the single-chip microcomputer, the source of the MOS transistor Q1 is connected to one end of the primary coil of the transformer TX, the negative pole Vin- of the DC voltage is connected to the other end of the primary coil of the transformer TX through a resistor Rs, and a capacitor C1 is provided between the positive pole Vin+ and the negative pole Vin- of the DC voltage. The secondary coil of the transformer TX outputs after passing through the rectifying and filtering circuit; the rectifying and filtering circuit includes a diode D1, a diode D2, an inductor L1, and a capacitor C2. One end of the secondary coil of the transformer is connected to the positive pole of the diode D1, the negative pole of the diode D1 is connected to the input end of the inductor L1, the output end of the inductor L1 is connected to the output positive pole, the other end of the secondary coil of the transformer TX is connected to the input end of the inductor L1 through the diode D2, the other end of the secondary coil of the transformer TX is connected to the output end of the inductor L1 through the capacitor C2, and the other end of the secondary coil of the transformer TX is connected to the output negative pole through a resistor R1.

[0012] Principle of the present utility model: The single-chip microcomputer controls the transformer TX through a PWM signal to make the primary coil of the transformer TX oscillate, forming an oscillation circuit; the secondary coil of the transformer outputs an isolated DC voltage through the rectifying and filtering circuit.

Claims

1. A DC isolation circuit for preventing interference, characterized in that: It includes a MOS tube Q1, a transformer TX and a rectifier filter circuit, the DC voltage positive electrode Vin+ is connected to the drain of the MOS tube Q1, the gate of the MOS tube Q1 is connected to the single-chip computer, the source of the MOS tube Q1 is connected to one end of the primary coil of the transformer TX, the DC voltage negative electrode Vin- is connected to the other end of the primary coil of the transformer TX through a resistor Rs, and the secondary coil of the transformer TX is output after passing through the rectifier filter circuit.

2. A DC isolation circuit for preventing interference according to claim 1, characterized in that: A capacitor C1 is provided between the DC voltage positive electrode Vin+ and the negative electrode Vin-.

3. A DC isolation circuit for preventing interference according to claim 1, characterized in that: The rectifier and filter circuit includes a diode D1, a diode D2, an inductor L1 and a capacitor C2. One end of the transformer secondary coil is connected to the positive electrode of the diode D1, the negative electrode of the diode D1 is connected to the input end of the inductor L1, the output end of the inductor L1 is connected to the output positive electrode, the other end of the transformer TX secondary coil is connected to the input end of the inductor L1 through the diode D2, the other end of the transformer TX secondary coil is connected to the output end of the inductor L1 through the capacitor C2, and the other end of the transformer TX secondary coil is connected to the output negative electrode through the resistor R1.

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