CN102497104B - Resonant transformation circuit applied to medical equipment and provided with synchronous rectification control - Google Patents
Resonant transformation circuit applied to medical equipment and provided with synchronous rectification control Download PDFInfo
- Publication number
- CN102497104B CN102497104B CN201110387403.2A CN201110387403A CN102497104B CN 102497104 B CN102497104 B CN 102497104B CN 201110387403 A CN201110387403 A CN 201110387403A CN 102497104 B CN102497104 B CN 102497104B
- Authority
- CN
- China
- Prior art keywords
- circuit
- synchronous rectification
- current
- diode
- secondary side
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000001360 synchronised effect Effects 0.000 title claims abstract description 105
- 230000009466 transformation Effects 0.000 title abstract 4
- 238000004804 winding Methods 0.000 claims abstract description 56
- 239000003990 capacitor Substances 0.000 claims description 28
- 238000006243 chemical reaction Methods 0.000 claims description 20
- 230000006698 induction Effects 0.000 claims description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 3
- 238000007599 discharging Methods 0.000 claims description 3
- 238000001914 filtration Methods 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 9
- 238000001514 detection method Methods 0.000 abstract description 6
- 230000002708 enhancing effect Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Landscapes
- Rectifiers (AREA)
Abstract
The invention belongs to a circuit system applied to signal controlling and processing of medical equipment and particularly relates to a resonant transformation circuit applied to medical equipment and provided with synchronous rectification control. The technical scheme provided by the resonant transformation circuit does not need a delay circuit, body diode voltage of a synchronous rectifier tube is not detected, and voltage signals are obtained directly after current in a secondary side winding is converted into low current through a current transformer, thereby reducing opening time of a body diode of the secondary side rectifier tube as much as possible, and further improving efficiency. Simultaneously, a current directly-driving method in the secondary side winding is adopted, thereby avoiding alternating conduction of an upper tube and a lower tube, and enhancing reliability of circuits in the medical equipment. In addition, the resonant transformation circuit does not need additional control circuits or zero passage detection, only needs the current transformer to convert the current into the low current so as to conveniently form driving voltage to drive a winding reset circuit of the current transformer, and is simple in circuit and low in cost.
Description
Technical Field
The invention belongs to a circuit system for controlling and processing signals applied to medical equipment, in particular to a resonant conversion circuit with synchronous rectification control applied to the medical equipment.
Background
The trend of switching power supplies is to miniaturize and lighten the power supplies, which means high efficiency and high power density, and also to put higher demands on electromagnetic compatibility. In terms of high power density, the number of turns of each winding of the transformer can be reduced by increasing the operating frequency, and the size of the core can be reduced, thereby reducing the size of the transformer. However, when the switching frequency is increased, the switching loss increases, the circuit efficiency is seriously reduced, and the electromagnetic interference also increases, so that it is not feasible to simply increase the switching frequency. Aiming at the problems, a soft switching technology is provided, which utilizes the resonance principle to enable a switching tube in a power supply to work in a zero-voltage conduction state, reduces the switching loss and the switching noise, improves the efficiency, reduces the electromagnetic interference and greatly improves the switching frequency.
Briefly describing the principle of implementing the resonant converter as a soft switch, the upper and lower switching tubes are alternately turned on, and 50% of the duty ratio of the upper and lower switching tubes are respectively provided with a dead time, and the dead time can be adjusted to prevent the upper and lower switching tubes from being turned on simultaneously, so as to ensure that the upper and lower switching tubes are not turned on simultaneously. The converter can work in the following frequency bands:
1. 
；
2. 
；
3. 
(partial region);
wherein,in order to be able to switch the frequency,
two characteristic resonant frequencies:
herein only in order to
The operation of the resonant half-bridge converter is illustrated by way of example. As shown in the waveform of FIG. 1, t 0-t 4 is a complete working cycle: during the period from t0 to t1, as shown in fig. 2, the half-bridge power switching tubes S1 and S2 are turned off, and the resonant circuit formed by the resonant inductor Ls and the series resonant capacitor Cs enables the S1 to realize zero-voltage switching-on; in the period from t1 to t2, the half-bridge circuit power switch tube S1 is conducted, wherein a short time is before t2, the series resonance inductor Ls, the series resonance capacitor Cs and the transformer inductor Lm form a resonance circuit, and the current of the secondary side rectification switch tube is 0; in the period from t2 to t3, power switching tubes S1 and S2 of the resonant circuit are turned off, and the series resonant inductor Ls and the resonant capacitor Cs form the resonant circuit, so that the S2 is switched on at the voltage of 0; during the period from t3 to t4, the resonant circuit power switch tube S2 is conducted, a short time is before t4, the resonant inductors Ls, Cs and Lm form a resonant circuit, and the current on the secondary side rectifying switch tube is also 0.
In order to optimally design the resonant circuit, the converter is generally operated at a point slightly greater than the resonant frequency fm under the condition of full load output of the rated input voltage, so that the converter enters the resonant circuit when the load changes or the voltage drops
And (4) a region.
Referring to fig. 2, a series resonant converter is shown in a half-bridge configuration. The power supply comprises a half-bridge circuit formed by more than one pair of power switches S1 and S2 and a resonant network, wherein the resonant network is formed by a resonant inductor Ls, a resonant capacitor Cs and an excitation inductor Lm of a transformer. The series resonant inductor Ls may be a leakage inductance of the transformer or an independent inductance. These three resonance parameters constitute the two characteristic resonance frequencies fs and fm of the resonant network:
the secondary side is a rectifying and smoothing circuit composed of transformer auxiliary windings Ns1 and Ns2, Q1, Q2 and an output capacitor, and the synchronous rectifying circuit is composed of a pair of power switching tubes Q1 and Q2 connected to the output capacitor Co.
The input end of the resonant converter is a direct current voltage Vin, and a transformer thereof isolates a half-bridge circuit and a resonant network from a synchronous rectification circuit through a primary side winding and two secondary side windings Ns1 and Ns2 connected in series in the same phase.
The key is in the synchronous rectification control circuit, in the prior art, a special control chip is used for controlling the synchronous rectification control circuit shown in figure 2, and the implementation method is that the drain-source voltage and the rising or falling edge of the synchronous rectification tubes Q1 and Q2 are detected to determine the driving voltage of the Q1 and Q2 and control the turn-on time of the synchronous rectification tubes, essentially, the body diodes of the switching tubes are required to be conducted, the voltage on the body diodes is detected, and the control chip can be driven by two signals sent by one control chip or can be respectively driven by two signals.
Due to the high-frequency switching characteristic of the switching power supply, turn-off noise can possibly cause the false triggering (mistaken turn-on or turn-off) of a switching tube, so that delay circuits and a jitter removal function are added to a plurality of control chips, the minimum turn-on time is ensured, but the efficiency improvement is limited under the condition of low-voltage heavy-current load; meanwhile, unnecessary synchronous rectifier tube loss is caused under the condition of small load, and the efficiency is not high when the load is light. In the prior art, there is also a current zero-crossing detection control driving circuit, as shown in fig. 3, a secondary side controller controls the on/off of a secondary side synchronous rectification circuit by detecting the zero-crossing of the secondary side winding current, so that the secondary side synchronous rectification circuit is turned on during the whole sinusoidal half-wave current period, and is turned off at other times. The core of the method is equal to the LLC synchronous rectification control chip idea of the mainstream manufacturer at present. Because of the current detection process, a certain time delay always exists between the current detection process and the output control signal, which leads to the conduction of the body diode of the body synchronous rectification switching tube, and the efficiency improvement is influenced.
Disclosure of Invention
To overcome the above drawbacks, the present invention is directed to a resonant converter circuit with synchronous rectification control for medical equipment.
The purpose of the invention is realized by the following technical scheme:
the invention relates to a resonance converting circuit with synchronous rectification control applied to medical equipment, which mainly comprises:
the secondary side circuit comprises a secondary side winding and a synchronous rectification circuit which are connected with each other, and is characterized by further comprising a current transformer which is connected with the secondary side winding and is used for converting large current into small current signals, and a current conversion voltage circuit which is connected between the current transformer and the synchronous rectification circuit and is used for converting current signals into voltage signals and driving the synchronous rectification circuit.
Furthermore, the current transformer comprises a main winding and an induction winding, one end of the main winding is connected with the secondary side winding, the other end of the main winding is connected with an output part of the secondary side circuit, one end of the induction winding is connected with the current conversion voltage circuit, and the other end of the induction winding is connected with the ground.
Furthermore, the synchronous rectification circuit comprises a synchronous rectification switching tube, and the current conversion voltage circuit is connected with the grid electrode of the synchronous rectification switching tube.
Furthermore, the number of the secondary side windings is two or more, each secondary side winding corresponds to one current transformer and one current conversion voltage circuit, the number of the synchronous rectification switch tubes corresponding to each secondary side winding is one or more, and if the synchronous rectification switch tubes are more than one, the synchronous rectification switch tubes are connected in parallel.
Furthermore, the secondary side circuit further comprises an output filter circuit, the output filter circuit is connected with the output part of the secondary side circuit, and the output filter circuit comprises an output capacitor and is used for filtering the voltage rectified by the synchronous rectification circuit, so that the output end obtains stable direct current output.
Furthermore, the bridge resonant circuit comprises a power switch tube, a leakage inductor, a transformer, a resonant capacitor and a primary side control chip which is connected between the grid electrode of the power switch tube and the output part of the secondary side circuit and used for generating a driving signal of the power switch tube and controlling the on-off of the power switch tube.
Furthermore, the winding ratio of the current transformer is more than or equal to 200: 1.
furthermore, the current transformer is made of iron powder core, and the shape is preferably annular.
Furthermore, the current-to-voltage conversion circuit comprises a capacitor, a first resistor, a first triode, a first diode, a second diode, a third diode and a fourth diode, wherein the capacitor, the third diode and the current transformer are sequentially connected to form a loop for charging the capacitor by the current transformer; the capacitor and the fourth diode are connected with the grid electrode of the rectifying switch tube and used for providing driving voltage for the rectifying switch tube; the first resistor, the first diode and the current transformer are sequentially connected, so that the current transformer discharges and demagnetizes; the base electrode of the first triode is connected with the positive electrode of the first diode, the collector electrode of the first triode is connected with the negative electrode of the first diode, and the emitter electrode of the first triode is connected with the positive electrode of the third diode, so that the turn-off of the synchronous rectifier tube is accelerated, and the turn-off time of the synchronous rectifier tube is shortened; the cathode of the second diode is connected with one end of the first resistor, and the anode of the second diode is connected with the anode of the first diode, so as to accelerate the turn-off of the first triode.
Furthermore, the current-to-voltage conversion circuit further comprises a second triode, a third triode, a second resistor, a third resistor and a fourth resistor, wherein the second triode and the third triode form a totem pole which is connected with the collector of the first triode and the grid of the rectifier switch tube and used for increasing the current driving capability; the second resistor is connected between the base electrode of the third triode and the ground and is used for timely discharging when the third triode is turned off; the third resistor is connected between the emitting electrode of the second triode and the grid electrode of the rectifying switch tube, the resistance value is variable, and the third resistor is used for reducing the conduction speed of the synchronous rectifying switch tube; the fourth resistor is connected between the capacitor and the ground and used for dividing voltage.
The invention relates to a medical device with a resonance conversion circuit with synchronous rectification control, which is applied to the medical device.
The technical scheme provided by the invention does not need a delay circuit and does not detect the voltage of the body diode of the synchronous rectifier tube, and the current in the secondary side winding is converted into a small current through L1 (or L2) to directly obtain a Vg signal (as shown in figures 5 and 6), thereby reducing the turn-on time of the body diode of the secondary side synchronous rectifier tube as much as possible and further improving the efficiency; meanwhile, the method of directly driving the current in the secondary side winding is adopted, so that the alternate conduction of an upper tube and a lower tube is fundamentally avoided, and the reliability of the circuit in medical equipment, such as ultrasonic imaging equipment, is improved; in addition, an additional control circuit or zero-crossing detection is not needed, only the current transformer converts the current into small current to conveniently form driving voltage to drive and a winding reset circuit of the current transformer, and the circuit is simple and low in cost.
Drawings
For ease of illustration, the present invention is described in detail by the following preferred embodiments and the accompanying drawings.
FIG. 1 shows the switching frequency of a resonant converter
A waveform diagram of time;
FIG. 2 is a prior art block diagram with a synchronous rectification LLC circuit;
FIG. 3 is another prior art block diagram with synchronous rectification LLC circuit;
FIG. 4 is a schematic block diagram of a resonant inverter circuit with synchronous rectification control for use in a medical device in accordance with the present invention;
FIG. 5 is a circuit diagram of an embodiment of a synchronous rectification control of a resonant inverter circuit with a synchronous rectification control applied to a medical device according to the present invention;
fig. 6 is a circuit diagram of another embodiment of the synchronous rectification control of the resonant inverter circuit with synchronous rectification control applied to the medical equipment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
For ease of understanding, a brief introduction to the principles of the present invention will be made before describing particular embodiments. Referring to fig. 4, the resonant converting circuit with synchronous rectification control applied to medical equipment according to the present invention adopts soft switching and secondary side synchronous rectification techniques for high efficiency switching power supply design.
The controller is arranged at the primary side circuit end to control the resonant circuit switch, and the main switch works in a zero-voltage switching-on state and maintains stable output voltage by controlling the working frequency of the controller; the synchronous rectification control of the secondary side is directly driven by the current of the secondary side, and the rectifying tube cannot be directly driven based on the large current, the synchronous rectification control circuit adopts the current transformer to convert the large current into a small current signal and then convert the small current signal into a voltage signal through the voltage conversion circuit to drive the synchronous rectifying tube, so that the on-off of the synchronous rectification switching tube is completely synchronous with the current of a winding, other auxiliary functions are not needed, the body diode conduction of the synchronous rectifying tube is greatly reduced, and the efficiency of a large current output circuit is improved to the greatest extent.
Meanwhile, the synchronous rectification switching tube is directly driven by winding current, so that the upper synchronous rectification tube and the lower synchronous rectification tube cannot be directly connected due to detection misjudgment of a control chip, and the reliability of the power supply is improved.
An example of a high efficiency switching power supply using the synchronous rectification control method in accordance with the above principle is described below.
As shown in fig. 4, 5 and 6, a resonant converter and a synchronous rectification control circuit thereof. As shown in fig. 4, the main circuit structure, in which a dc input Vin is used as an input of a power supply, includes:
a bridge resonant circuit, the section comprising: at least one pair of power switch tubes S1, S2, a transformer Lm and a leakage inductor Ls (which can also be an independent inductor), and a resonant capacitor Cs; the primary side control chip is used for generating a driving signal of the primary side power switching tube, controlling the on-off of the driving signal, enabling the upper tube and the lower tube to be conducted in a staggered mode, working under the state of fixed duty ratio (about 50%), adjusting the working frequency to realize the stability of output voltage and ensuring that the switching tube is switched on at zero voltage, and the detailed connection relation is shown in fig. 4;
a secondary side circuit, comprising: the synchronous rectification circuit comprises secondary side windings (Ns1 and Ns2, the number of the windings can be two or more), a synchronous rectification circuit (each winding corresponds to one synchronous rectification circuit) and an output filter circuit, wherein the synchronous rectification circuit comprises at least two synchronous rectification switch tubes (Q1 and Q2, each winding corresponds to one or more synchronous rectification switch tubes, if the number of the windings corresponds to a plurality of synchronous rectification switch tubes, the synchronous rectification switch tubes are connected in parallel with each other) and are respectively used for rectifying the voltage of the secondary side windings Ns1 and Ns2, and driving signals of the secondary side windings are generated by corresponding winding currents. The current transformers L1 and L2 (each secondary side winding corresponds to one current transformer) are respectively provided with two parts of windings, one end of a main winding is connected with the secondary side winding, the other end of the main winding is connected with an output part, and the output rated current flows through the output part; one end of the other winding of the current transformer, also called an induction winding, is connected with the current conversion voltage circuit, and the other end of the other winding of the current transformer is connected with the ground; the output filter circuit comprises an output capacitor Co which is used for filtering the voltage rectified by the synchronous rectification switch tube so as to ensure that the output end obtains stable direct current output. And the current-to-voltage conversion circuit is connected between the current transformer and the synchronous rectification circuit and is used for converting a current signal into a voltage signal and driving the synchronous rectification circuit, and the current-to-voltage conversion circuit is connected with the grid electrode of the synchronous rectification switching tube. Fig. 5 and 6 show two implementations of the voltage conversion circuit in synchronous rectification control according to the present invention.
One embodiment of the current-to-voltage circuit shown in fig. 5 is described in detail as follows:
the current-to-voltage conversion circuit comprises: the capacitor C1, the first resistor R1, the first triode Q1, the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 are sequentially connected to form a loop, and the loop is used for charging the capacitor by the current transformer; the capacitor and the fourth diode are connected with the grid electrode of the rectifying switch tube and used for providing driving voltage for the rectifying switch tube; the first resistor, the first diode and the current transformer are sequentially connected, so that the current transformer discharges and demagnetizes; the base electrode of the first triode is connected with the positive electrode of the first diode, the collector electrode of the first triode is connected with the negative electrode of the first diode, and the emitter electrode of the first triode is connected with the positive electrode of the third diode, so that the turn-off of the synchronous rectifier tube is accelerated, and the turn-off time of the synchronous rectifier tube is shortened; the cathode of the second diode is connected with one end of the first resistor, and the anode of the second diode is connected with the anode of the first diode, so as to accelerate the turn-off of the first triode.
The specific principle is described as follows: under the condition that the current of a current transformer is positive, the current transformer L1 charges C1 through a capacitor C1 and a diode D3 to obtain a driving voltage, a voltage Vg obtained through the diode D4 drives a synchronous rectification switch tube, D4 has the function of preventing the Vg from flowing backwards so as to prevent the synchronous rectification switch tube from being turned off by mistake, and at the moment, a triode Q1 is in a turn-off state; in this embodiment, the upper and lower synchronous rectifiers each have their own driving circuit, and after the current is 0 and is reversed, the resistor R1, the diode D1, and the current transformer L1 form a current loop to discharge the current transformer L1, that is, the current transformer L1 is demagnetized through the resistor R1 and the diode D1 to prepare for the next driving voltage generation, and at the same time, the turn-off of the synchronous rectifier is accelerated by turning on the triode Q1 to reduce the turn-off time of the synchronous rectifier, and after the reverse current is reduced to 0 and positive, the diode D2 accelerates the turn-off of the triode Q1, and the current transformer L1 starts the next cycle in a state where the capacitor C1 is charged through the capacitor C1 and the diode D3 to obtain a driving voltage. Therefore, in the small dead time, the body diode of the synchronous rectifier tube is not conducted any more, and the efficiency of the converter is improved.
Another embodiment of the current-to-voltage circuit shown in fig. 6 is described in detail as follows:
compared with the embodiment of fig. 5, the current-to-voltage conversion circuit further comprises: the current driving circuit comprises a second triode Q2, a third triode Q3, a second resistor R2, a third resistor R3 and a fourth resistor R4, wherein the second triode and the third triode form a totem pole which is connected with a collector electrode of the first triode and a grid electrode of the rectifying switch tube and used for increasing current driving capability; the second resistor is connected between the base electrode of the third triode and the ground and is used for timely discharging when the third triode is turned off; the third resistor is connected between the emitting electrode of the second triode and the grid electrode of the rectifying switch tube, the resistance value is variable, and the third resistor is used for reducing the conduction speed of the synchronous rectifying switch tube; the fourth resistor is connected between the capacitor and the ground and used for dividing voltage.
The specific principle is described as follows: the driving signal of the synchronous rectifier tube on the secondary side is generated, which can be directly driven by the winding current through resistance sampling, but because the current may be too large or the precision is not enough, the current transformer is an accurate choice, and can convert the minimum current into voltage to drive the switch tube to the maximum extent, if the driving capability of the driving signal is not enough to drive the switch tube to be driven, a totem pole composed of triodes Q2 and Q3 is added at the output end of the driving signal to increase the driving capability, R3 is a driving resistor, and is connected to the synchronous rectifier switch tube to reduce the conduction speed of the synchronous rectifier switch tube, and the resistance value of the resistor can be changed and can be as small as 0; the resistor R2 is used to discharge Q3 when transistor Q3 is off, and its supply VCC is provided by the output voltage or other voltage, so that the current flowing through the synchronous rectifier can track the primary current to the maximum extent.
In this embodiment, the upper and lower synchronous rectifiers require respective current driving circuits, so there are two current transformers. The larger the ratio of the current transformer is, the better the effect is, generally speaking, the winding ratio of the current transformer is more than 200:1, the current transformer is made of iron powder core, and the shape is preferably annular.
Table 1 below further illustrates the power supply high efficiency characteristics using this synchronous rectification method.
Table 1: example power supply efficiency (output 19V):
when the number of the synchronous rectifiers is larger, the driving capability of the circuit may be insufficient, and the driving capability needs to be increased, so that the driving circuit is increased, as shown in fig. 6, and other parts are the same as those in fig. 4.
The medical equipment comprises a medical monitor, an ultrasonic diagnostic apparatus, an electrocardiograph, a poct blood-gas analyzer and the like.
It should be noted that many alternatives to the variations described herein are possible, such as: different complex magnetic modes of the current transformer and the like; for those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
Claims (10)
1. A resonance converting circuit with synchronous rectification control applied to medical equipment comprises a bridge type resonance circuit and a secondary side circuit connected with the bridge type resonance circuit, wherein the secondary side circuit comprises a secondary side winding and a synchronous rectification circuit which are connected with each other;
the current transformer comprises a main winding and an induction winding, one end of the main winding is connected with the secondary side winding, the other end of the main winding is connected with an output part of the secondary side circuit, one end of the induction winding is connected with the current conversion voltage circuit, and the other end of the induction winding is connected with the ground.
2. The resonant inverter circuit with synchronous rectification control applied to medical equipment according to claim 1, wherein the synchronous rectification circuit comprises a synchronous rectification switching tube, and the current conversion voltage circuit is connected with a grid electrode of the synchronous rectification switching tube.
3. The resonant converter circuit with synchronous rectification control applied to medical equipment according to claim 2, wherein the number of the secondary windings is two or more, each secondary winding corresponds to one current transformer and one current conversion voltage circuit, the number of the synchronous rectification switching tubes corresponding to each secondary winding is one or more, and if the number of the synchronous rectification switching tubes is more than one, the synchronous rectification switching tubes are connected in parallel.
4. The resonant inverter circuit with synchronous rectification control as claimed in claim 3, wherein the secondary side circuit further comprises an output filter circuit, the output filter circuit is connected to the output portion of the secondary side circuit, and the output filter circuit comprises an output capacitor for filtering the voltage rectified by the synchronous rectification circuit to obtain a stable dc output at the output terminal.
5. The resonant converter circuit with synchronous rectification control as claimed in claim 1, wherein the bridge resonant circuit comprises a power switch, a leakage inductor, a transformer, a resonant capacitor, and a primary side control chip connected between the gate of the power switch and the output of the secondary side circuit for generating a driving signal of the power switch to control the on/off of the power switch.
6. The resonant inverter circuit with synchronous rectification control applied to medical equipment according to claim 1, wherein the winding ratio of the current transformer is greater than or equal to 200: 1.
7. the resonant inverter circuit with synchronous rectification control as claimed in claim 1, wherein the current transformer is made of iron powder core and is annular.
8. The resonant converter circuit with synchronous rectification control applied to medical equipment according to claim 1, wherein the current-to-voltage conversion circuit comprises a capacitor, a first resistor, a first triode, a first diode, a second diode, a third diode and a fourth diode, and the capacitor, the third diode and the current transformer are connected in sequence to form a loop for charging the capacitor with the current transformer; the capacitor, the fourth diode and the grid electrode of the rectification switch tube are connected and used for providing driving voltage for the rectification switch tube; the first resistor, the first diode and the current transformer are sequentially connected, so that the current transformer discharges and demagnetizes; the base electrode of the first triode is connected with the positive electrode of the first diode, the collector electrode of the first triode is connected with the negative electrode of the first diode, and the emitter electrode of the first triode is connected with the positive electrode of the third diode, so that the turn-off of the synchronous rectifier tube is accelerated, and the turn-off time of the synchronous rectifier tube is shortened; the cathode of the second diode is connected with one end of the first resistor, and the anode of the second diode is connected with the anode of the first diode, so as to accelerate the turn-off of the first triode.
9. The resonant converting circuit with synchronous rectification control as claimed in claim 8, wherein the current converting voltage circuit further comprises a second transistor, a third transistor, a second resistor, a third resistor and a fourth resistor, the second transistor and the third transistor are formed into a totem pole and connected with the collector of the first transistor and the gate of the rectification switch tube for increasing the current driving capability; the second resistor is connected between the base electrode of the third triode and the ground and is used for timely discharging when the third triode is turned off; the third resistor is connected between the emitting electrode of the second triode and the grid electrode of the rectifying switch tube, the resistance value is variable, and the third resistor is used for reducing the conduction speed of the synchronous rectifying switch tube; the fourth resistor is connected between the capacitor and the ground and used for dividing voltage.
10. A medical device having a resonant inverter circuit with synchronous rectification control as claimed in claim 1, comprising a power circuit, wherein said power circuit comprises a resonant inverter circuit with synchronous rectification control as claimed in claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110387403.2A CN102497104B (en) | 2011-11-30 | 2011-11-30 | Resonant transformation circuit applied to medical equipment and provided with synchronous rectification control |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110387403.2A CN102497104B (en) | 2011-11-30 | 2011-11-30 | Resonant transformation circuit applied to medical equipment and provided with synchronous rectification control |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102497104A CN102497104A (en) | 2012-06-13 |
| CN102497104B true CN102497104B (en) | 2014-04-30 |
Family
ID=46188902
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110387403.2A Active CN102497104B (en) | 2011-11-30 | 2011-11-30 | Resonant transformation circuit applied to medical equipment and provided with synchronous rectification control |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102497104B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103441683B (en) * | 2013-09-12 | 2015-09-23 | 深圳开立生物医疗科技股份有限公司 | A kind of active clamp forward power circuit |
| ITUB20153819A1 (en) * | 2015-09-23 | 2017-03-23 | St Microelectronics Srl | PILOT CIRCUIT FOR SWITCHES SYNCHRONOUS RECTIFIERS IN RESONANT CONVERTERS, CONVERTER AND CORRESPONDENT PROCEDURE |
| CN110277914B (en) * | 2019-07-19 | 2020-11-27 | 电子科技大学 | Reverse flow comparator suitable for Boost converter |
| CN113804945B (en) * | 2021-09-17 | 2022-07-12 | 西安交通大学 | Current detection circuit, detection method and control method for synchronous rectification in high-frequency LLC (logical Link control) |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11356044A (en) * | 1998-04-10 | 1999-12-24 | Sony Corp | Resonance type switching power supply |
| US7688600B2 (en) * | 2004-11-29 | 2010-03-30 | Nxp B.V. | Multi-Resonance converter |
| CN1787349A (en) * | 2005-12-10 | 2006-06-14 | 陈广华 | Vacuum electronic auto-power-cutting switch |
| GB2455568A (en) * | 2007-12-14 | 2009-06-17 | Eltek Valere As | Protection system for a resonant converter with synchronous rectification |
| CN101471606A (en) * | 2007-12-26 | 2009-07-01 | 深圳迈瑞生物医疗电子股份有限公司 | LLC resonant transformation device |
| CN101667783B (en) * | 2008-09-05 | 2013-01-30 | 艾默生网络能源系统北美公司 | Synchronous rectification drive device and method for converter |
-
2011
- 2011-11-30 CN CN201110387403.2A patent/CN102497104B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN102497104A (en) | 2012-06-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Kummari et al. | An isolated high-frequency link microinverter operated with secondary-side modulation for efficiency improvement | |
| Zhang et al. | A current-driving synchronous rectifier for an LLC resonant converter with voltage-doubler rectifier structure | |
| Xie et al. | A novel high frequency current-driven synchronous rectifier applicable to most switching topologies | |
| Borage et al. | A full-bridge DC–DC converter withzero-voltage-switching overthe entire conversion range | |
| US8837174B2 (en) | Switching power-supply apparatus including switching elements having a low threshold voltage | |
| US10686387B2 (en) | Multi-transformer LLC resonant converter circuit | |
| Zhang et al. | A novel zero-current-transition full bridge DC/DC converter | |
| JP5591666B2 (en) | DC-DC converter | |
| KR101000561B1 (en) | Series resonant converter | |
| KR20070037384A (en) | Switching power supply circuit | |
| CN108448902B (en) | Synchronous rectification flyback DC-DC power supply conversion device and control method | |
| US8064228B2 (en) | Power supply apparatus with current-sharing function | |
| CN102497104B (en) | Resonant transformation circuit applied to medical equipment and provided with synchronous rectification control | |
| Dong et al. | A new CCM/DCM hybrid-mode synchronous rectification flyback converter | |
| CN108964473A (en) | A kind of high efficiency high voltage power supply translation circuit | |
| CN203722491U (en) | Alternating current-direct current conversion circuit and alternating current-direct current converter | |
| CN107947587A (en) | A kind of high-efficiency constant-flow Width funtion output circuit | |
| CN108667304B (en) | Synchronous rectification flyback DC-DC power supply conversion device and control method | |
| TWI617126B (en) | Power converter and control method thereof | |
| JP2005073335A (en) | Switching power supply circuit | |
| Balakrishnan et al. | Phase Shift Controlled Full Bridge DC-DC Converter with Less Circulating Loss | |
| CN113381611B (en) | Control method and control device of flyback converter | |
| Moosavi et al. | Soft-switching push-pull converter with parallel resonant link and buck-boost capability | |
| TWI543513B (en) | Resonant converter | |
| KR102142630B1 (en) | Driving circuit of voltage driven synchronous rectifier |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |