Inverter circuit for suppressing electric power conducted interference

Abstract

The invention discloses a reverse current device circuit to inhibit power conducted interference. Wherein, receiving output signal from power input circuit, outputting operating frequency; using a drive unit to receive said frequency and cut signal and output drive signal; using a transformation unit to receive said drive signal and take power conversion to drive first load action; arranging an isolation unit between drive and control units to divide grounding type of drive unit and control unit as non-share grounding with first and secondary sides of transformation unit. Thereby, the control unit outputs stable operating frequency and realize inhibiting effect.

Description

technical field [0001] The invention relates to an inverter circuit for suppressing electric power conduction interference, in particular to an inverter circuit for converting large and small currents and high and low voltage power at the same time. Background technique [0002] see figure 1 Shown is a schematic block diagram of the power supply circuit of video products such as traditional LCD screens or LCD TVs. When the video product is connected to the AC input unit of the mains, the AC power signal is input from the AC input unit, and the AC power signal passes through the diode The rectifier unit composed of the group performs power conversion and outputs a pulsed DC power signal, and then performs power factor correction by a power factor adjustment unit to become a regulated DC power signal, and the regulated DC power signal is output in parallel to an inverter ( inverter), and through the second drive circuit to a second transformation unit, the second transformati...

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Problems solved by technology

[0003] From the circuit block diagram of traditional video products, it can be seen that since the power source belongs to the same rectifier unit and the same drive circuit, the first load and the second load are in a common ground state, and because the second load is driven by low-voltage power, And it is necessary to maintain a stable DC power signal during the driving process. If the power signal is disturbed and fluctuates, it will affect the effect of the second load action, such as ripples on the display screen, uneven color response, and impure sound quality and noise from the speaker output. Another phenomenon of power interference lies in the inverter circuit, because the inverter circuit includes a control unit that outputs the operating frequency, a drive unit that receives the operating frequency cutting power signal and outputs a drive signal, and a drive unit that receives the operating frequency The drive signal performs power conversion and outputs a high-voltage power signal to drive the first transformation unit of the first load, such as figure 2 As shown, when the drive unit cuts the power signal at the working frequency, it adopts the charging and discharging mode, which causes the power signal to fluctuate. This fluctuating signal will also affect the control unit, resulting in unstable working frequency and flickering of the first load.

[0004] The main reason for the interference is that the boosting action of the inverter adopts a oscillating and fluctuating method. The fluctuating electric energy will affect the second load and the control unit from the common ground terminal, so that the second load and the control unit will be disturbed by the power conduction of the inverter. The above-mentioned defects occur, this phenomenon is especially easy to occur on large-scale video products, and has a great impact on the normal image and audio performance of video products

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