阅读说明：本技术 一种变压器同步整流控制装置 (Synchronous rectification control device of transformer ) 是由 陆德刚 于 2019-11-23 设计创作，主要内容包括：本发明公开了一种变压器同步整流控制装置,包括滤波电路和变压器次级,所述变压器次级的输出端电性连接有同步整流管,同步整流管的输出端与滤波电路相连接；所述滤波电路的输出端分别电性连接有三极管和限幅电路,该三极管与限幅电路相连接。本发明采集变压器次级电压不需要进行地隔离处置,减少隔离元件如互感器、驱动芯片等器件的使用,能够通过电阻、三极管实现变压器次级的同步整流控制,同时提高了电路的抗干扰能力,有效防止同步整流控制同时输出正脉冲后,同步整流管直通损坏,提高同步整流电路可靠性。(The invention discloses a transformer synchronous rectification control device, which comprises a filter circuit and a transformer secondary, wherein the output end of the transformer secondary is electrically connected with a synchronous rectifier tube, and the output end of the synchronous rectifier tube is connected with the filter circuit; the output end of the filter circuit is respectively and electrically connected with a triode and an amplitude limiting circuit, and the triode is connected with the amplitude limiting circuit. According to the invention, the secondary voltage of the transformer is collected without being isolated, the use of isolation elements such as a mutual inductor, a driving chip and the like is reduced, the synchronous rectification control of the secondary voltage of the transformer can be realized through the resistor and the triode, the anti-interference capability of the circuit is improved, the direct connection damage of the synchronous rectification tube is effectively prevented after the synchronous rectification control outputs positive pulses at the same time, and the reliability of the synchronous rectification circuit is improved.)

1. A transformer synchronous rectification control device comprises a filter circuit (3) and a transformer secondary (2), and is characterized in that: the output end of the transformer secondary (2) is electrically connected with a synchronous rectifier tube (1), and the output end of the synchronous rectifier tube (1) is connected with a filter circuit (3); the output end of the filter circuit (3) is respectively and electrically connected with a triode (5) and an amplitude limiting circuit (4), and the triode (5) is connected with the amplitude limiting circuit (4).

2. The synchronous rectification control device of the transformer according to claim 1, wherein: the filter circuit (3) comprises resistors R1, R2, R3 and a capacitor Co, and the filter circuit (3) is used for filtering high-frequency interference in the voltage signal.

3. The synchronous rectification control device of the transformer according to claim 1, wherein: the amplitude limiting circuit (4) comprises a PNP type triode, and the amplitude limiting circuit (4) is used for carrying out feedback adjustment on a voltage signal so as to achieve amplitude limiting.

4. The synchronous rectification control device of the transformer according to claim 1, wherein: the triode (5) adopts any one of MBT5551DW1T1G/3G type, MMBTH10-SOT-23-3EM type and 1SS181-SOT-23-A3 type triodes.

5. The synchronous rectification control device of the transformer according to claim 1, wherein: the synchronous rectifier tube (1) adopts a SUM110N 04-02L-shaped rectifier tube.

Technical Field

The invention relates to the technical field of synchronous rectification control, in particular to a synchronous rectification control device based on transformer secondary voltage acquisition and processing, and particularly relates to a transformer synchronous rectification control device.

Background

In an aviation switching power supply system, a secondary of a transformer generally adopts a Schottky rectifier diode for rectification, a synchronous rectification technology is used under the condition of low-voltage large-current load, the conduction loss of the diode is greatly reduced, the efficiency of the switching power supply is improved, and in order to ensure that the synchronous rectification is effectively conducted and cut off, a synchronous rectification control technology based on the collection and processing of primary side current of the transformer is adopted at present so as to improve the efficiency of the switching power supply and ensure that the synchronous rectification is effectively conducted and cut off.

However, in the existing synchronous rectification control system based on the collection and processing of the primary side current of the transformer, when the current of the primary side transformer is collected for synchronous rectification control, under transient conditions such as heavy load sudden loading and sudden unloading, the synchronous rectification control circuit is easy to generate interference, and because the primary side current of the transformer collected by the mutual inductor is easy to be interfered, positive pulse is generated in the turned-off synchronous rectification tube circuit, the synchronous rectification circuit is directly damaged, and the use of the synchronous rectification control system on the secondary side of the transformer is not facilitated.

Disclosure of Invention

The invention aims to provide a synchronous rectification control device of a transformer, which aims to solve the problem that the prior control system provided by the background art is directly damaged by a synchronous rectification circuit due to the fact that the primary side current of the transformer acquired by a mutual inductor is easily interfered and positive pulses are generated in a switched-off synchronous rectification tube circuit.

In order to achieve the purpose, the invention provides the following technical scheme: the transformer comprises a filter circuit and a transformer secondary, wherein the output end of the transformer secondary is electrically connected with a synchronous rectifier tube, and the output end of the synchronous rectifier tube is connected with the filter circuit; the output end of the filter circuit is respectively and electrically connected with a triode and an amplitude limiting circuit, and the triode is connected with the amplitude limiting circuit.

Preferably, the filter circuit comprises resistors R1, R2, R3 and a capacitor Co, and the filter circuit is used for filtering high-frequency interference in the voltage signal.

Preferably, the limiter circuit includes a PNP type triode, and the limiter circuit is used for performing feedback adjustment on the voltage signal to achieve limiting.

Preferably, the triode adopts any one of an MBT5551DW1T1G/3G type triode, an MMBTH10-SOT-23-3EM type triode and a 1SS181-SOT-23-A3 type triode.

Preferably, the synchronous rectifier tube adopts a SUM110N 04-02L-shaped rectifier tube.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, the secondary voltage of the transformer is collected without being isolated, the use of isolation elements such as a mutual inductor, a driving chip and the like is reduced, the synchronous rectification control of the secondary side of the transformer can be realized through a resistor and a triode, the circuit is simple, feasible and reliable, and the anti-interference performance is easier than that of a control system of the primary side current of the transformer; meanwhile, the voltage acquisition improves the anti-interference capability of the circuit, effectively prevents the direct connection damage of the synchronous rectifier tube after the synchronous rectifier control outputs positive pulses at the same time, improves the reliability of the synchronous rectifier circuit, and is favorable for popularization and application of the transformer secondary-based synchronous rectifier control system.

Drawings

FIG. 1 is a schematic block diagram of a control device of the present invention;

FIG. 2 is a circuit diagram of the synchronous rectification control circuit of the present invention.

In the figure: 1 synchronous rectifier tube, 2 transformer secondaries, 3 filter circuits, 4 amplitude limiting circuits and 5 triodes.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, the present invention provides a technical solution: the transformer rectifier comprises a filter circuit 3 and a transformer secondary 2, wherein the output end of the transformer secondary 2 is electrically connected with a synchronous rectifier tube 1, and the synchronous rectifier tube 1 adopts an SUM110N 04-02L-shaped rectifier tube; the output end of the synchronous rectifier tube 1 is connected with the filter circuit 3; the filter circuit 3 comprises resistors R1, R2, R3 and a capacitor Co, and the filter circuit 3 is used for filtering out high-frequency interference in the voltage signal; the output end of the filter circuit 3 is electrically connected with a triode 5 and an amplitude limiting circuit 4 respectively, and the triode 5 is connected with the amplitude limiting circuit 4; the amplitude limiting circuit 4 comprises a PNP type triode, and the amplitude limiting circuit 4 is used for carrying out feedback adjustment on the voltage signal so as to achieve amplitude limiting.

Referring to fig. 2, the limiter circuit 4 includes a PNP transistor, and further includes Q1 and Q2; the synchronous rectification control system based on the voltage acquisition and processing of the secondary side of the transformer further comprises diodes D1, D2 and D3, wherein the diodes adopt any one of FR10-FR60 type and 2A01-2A07 type; wherein, the amplitude limiting circuit 4 can be a circuit for flattening the amplitude of the signal voltage according to a limited range, and is also called an amplitude limiter or a wave clipper.

Referring to fig. 2, when the voltage of SEC1 IS higher than-IS, the PN junction of the U1 triode b1c1 IS not turned on, the 12V power supply IS turned on through the PN junction in the resistor R1 and the b2e2 of the U1 triode, the totem-pole input IS pulled low, the driving pulse of the synchronous rectifier 1 IS low, and the synchronous rectifier M1 IS not turned on; when SEC1 IS lower than-IS, the PN junction of the U1 triode b1c1 IS conducted, the PN junction of the 12V power supply through the resistor R1 and the U1 triode b2e2 IS not conducted, the totem pole input IS 12V high level, the driving pulse of the synchronous rectifier tube 1 IS high, and the synchronous rectifier tube M1 IS conducted; the control circuit principle of the synchronous rectifier M2 in the figure is the same, and only the synchronous rectifier M1 is conducted complementarily.

Wherein, the triode 5 adopts any one of MBT5551DW1T1G/3G type, MMBTH10-SOT-23-3EM type and 1SS181-SOT-23-A3 type triodes; the secondary transformer 2 adopts any one of BK-50VA type, SG-4KVA type, JR/R-65 type and CD1632-80 type transformers.

The voltage of the secondary 2 of the transformer is not required to be isolated, the use of isolation elements can be reduced, devices such as a mutual inductor and a driving chip are omitted, the circuit can realize synchronous rectification control of the secondary of the transformer through a resistor and a triode 5, the circuit is simple, feasible and reliable, and is easier to resist interference compared with the control technology of the primary side current of the transformer, the voltage acquisition improves the anti-interference capability of the circuit, the direct connection damage of a synchronous rectifier tube 1 is effectively prevented after the synchronous rectification control outputs positive pulses at the same time, and the reliability of the synchronous rectification circuit is improved; the problem of current control system because transformer primary side current that the mutual-inductor gathered easily receives the interference, produces positive pulse signal in synchronous rectifier tube 1 circuit that shuts off, leads to synchronous rectifier circuit to lead to directly leading to the damage is solved.

The synchronous rectifier tube 1 adopts a special power MOSFET with extremely low on-state resistance to reduce the rectification loss, can greatly improve the efficiency of an AC/DC converter, does not have dead zone voltage caused by Schottky barrier voltage, belongs to a voltage control device, has linear volt-ampere characteristics when being conducted, and can complete the rectification function only by requiring the grid voltage to be synchronous with the phase of rectified voltage when the power MOSFET is used as a rectifier.

The triode 5 is a semiconductor device for controlling current, is used for amplifying a weak signal into an electric signal with a large amplitude value and is also used as a contactless switch; the transistor 5 is one of semiconductor basic components, has a current amplification function, and is a core element of an electronic circuit.

The filter circuit 3 is commonly used for filtering out ripples in the rectified output voltage, and generally comprises reactance elements, such as a capacitor C connected in parallel with two ends of a load resistor, or an inductor L connected in series with the load, and various complex filter circuits formed by capacitors and inductors; the filter circuit 3 comprises resistors R1, R2, R3 and a capacitor Co, the filter circuit 3 is used for filtering high-frequency interference in voltage signals, and the resistors R1, R2 and R3 are all powered by a 12V power supply.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.