CN218850636U - High-voltage output circuit - Google Patents
High-voltage output circuit Download PDFInfo
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- CN218850636U CN218850636U CN202222614707.4U CN202222614707U CN218850636U CN 218850636 U CN218850636 U CN 218850636U CN 202222614707 U CN202222614707 U CN 202222614707U CN 218850636 U CN218850636 U CN 218850636U
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- 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
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Abstract
The utility model discloses a high-voltage output circuit, which comprises an input rectification circuit, a starting circuit, a push-pull control chip, a transformer and an output rectification circuit; the first input end of the input rectifying circuit, the input end of the starting circuit and the first lead end of the primary winding of the transformer are all connected with an input power supply; the output end of the starting circuit is connected with the input pin of the push-pull control chip; one of output pins of the push-pull control chip is connected with a second lead end of a primary winding of the transformer; the second input end and the second output end of the input rectifying circuit and the grounding pin of the excitation push-pull control chip are connected with the input grounding port; the output rectifying circuit is coupled with the secondary winding of the transformer and then connected with the output end. According to the transformer, high-voltage output can be obtained only by using a single output pin of the excitation push-pull control chip, and compared with the existing self-excitation push-pull technology, the number and the number of turns of the transformer winding can be effectively reduced, and the purposes of reducing the volume and improving the product efficiency are achieved.
Description
Technical Field
The utility model relates to a switching power supply field especially relates to a be applied to DC power supply's ionizer's high-voltage output circuit.
Background
At present, a self-excited push-pull scheme is commonly used in a power supply mode of a direct-current high-voltage power supply, please refer to fig. 1,the scheme comprises a pair of push-pull triodes TR1 and TR2, a transformer, a constant current source IC1, a bias-proof magnetic resistor R1 and a resonant capacitor C1; the working principle is as follows, wherein V fb The result is fed back to the output terminal.
(1) A starting stage: when the product is started and powered on, V is not completely established because the output voltage is not completely established fb At high level, the current is supplied to the feedback winding N through a constant current source IC1 f1 And N f2 And finally, the current is added to the base electrodes of the triodes TR1 and TR2, and because the triodes TR1 and TR2 cannot be completely the same in parameters, such as amplification factor, conduction voltage drop and the like, the currents injected into the base electrodes of the triodes TR1 and TR2 cannot be absolutely balanced, the currents flowing through the collector electrodes of the two triodes cannot be completely consistent, and one triode is bound to be firstly conducted. Assuming that TR1 is first turned on, the magnitude and direction of the magnetic flux of the transformer are determined by the collector current flowing through TR1, and the change in the magnetic flux will cause an induced electromotive force on the feedback winding. From Lenz's law, the primary winding N p1 The polarity is negative for the homonym terminal and positive for the synonym terminal. And according to the law of electromagnetic induction, the feedback winding N f1 The homonymous terminal is negative, and the heteronymous terminal is positive, so that the base voltage V of the triode TR1 be Becomes larger to further make the base current I of TR1 b Increasing → TR1 conduction voltage drop V ce_on Get smaller → I c1 Become large → N f1 Induced voltage becoming large → I b The triode TR1 is in a positive feedback state when the voltage is increased; in the same way, N f2 The dotted terminal of the induced voltage is negative, I c2 The transistor TR2 is made to be in an off state by the reduction. The potential of the base electrode of the TR2 is reduced due to the induced electromotive force of the feedback winding, the potential of the base electrode of the TR1 is increased, positive feedback is formed, the collector current of the TR2 is made to be smaller and smaller, and the collector current of the TR1 is made to be larger and larger. The resultant magnetic flux increases, and the interaction of the change of the magnetic flux and the induced electromotive force causes TR1 to tend to be saturated and turned on, and TR2 to tend to be turned off.
(2) And a magnetic core overturning stage: the essence of the core flipping is that the transformer flux no longer changes, i.e.
. By
The total input current of the TR1 base is limited by the maximum current of the constant current source, and when the current of the collector does not change any more, the change rate of the magnetic flux is zero, and the induced electromotive force in direct proportion to the change rate of the magnetic flux is also zero. Thus, when the field current on the transformer cannot be increased any more, the magnetic flux no longer changes, and the core flips. The disappearance of the induced electromotive force on the feedback winding causes the base potential V of TR1 be Reduced, collector current I of TR1 c1 Also decreases, the rate of change of the current reverses, causing the rate of change of the magnetic flux to reverse, thereby causing the induced electromotive force of the winding to reverse, i.e., the feedback winding N f1 、N f2 The homonymous end of (1) is positive, and the synonym end of (2) is negative. Further, the base potential of TR2 is increased, the base potential of TR1 is decreased, and positive feedback is formed, so that the collector current I of TR1 is increased c1 Smaller and smaller collector current I of TR2 c2 Are becoming larger and larger. The resultant magnetic flux increases, and the interaction of the change of the magnetic flux and the induced electromotive force causes TR2 to tend to be saturated and turned on, and TR1 to tend to be turned off. The total input current of the base electrode until TR2 is limited by the maximum current of the constant current source again, the current of the collector electrode does not change, the magnetic flux change rate is zero, the induced electromotive force which is in direct proportion to the magnetic flux change rate is zero again, and the magnetic core is turned over again. The above processes are repeated continuously, so that oscillation is formed on the secondary side of the transformer, and stable output voltage is formed by matching the secondary side of the transformer with the rectifying circuit.
From the above description of the working principle, it can be seen that the solution has the following drawbacks:
1. two push-pull triodes of the self-excitation push-pull scheme work in a linear region, and dead time is long, so that the loss is inevitably large;
2. the transformer needs to use a plurality of windings to jointly form a push-pull driving circuit, so that the volume of the transformer is increased;
3. according to the scheme, energy is provided for the secondary side at the forward moment, when the voltage is boosted through the transformer, the boosting ratio is the turn ratio of the primary side and the secondary side of the transformer, and under the condition that the input voltage is constant, the number of turns of the secondary side winding of the transformer needs to be more, and the volume of the transformer is increased.
Therefore, how to achieve the advantages of small volume and high efficiency while obtaining high direct current high voltage output is a technical problem to be solved urgently.
SUMMERY OF THE UTILITY MODEL
In view of this, the utility model provides a high-voltage output circuit to satisfy on exporting the basis of the high enough high direct current of height, only need use it to stimulate an output pin of push-pull chip and a primary winding of transformer, can compromise the market demand of the power product of small volume, high efficiency and low loss.
In order to achieve the above purpose, the utility model adopts the following technical scheme:
in a first aspect, a high voltage output circuit is provided, which comprises an input rectification circuit, a starting circuit, a push-pull control chip, a transformer and an output rectification circuit;
the first input end of the input rectifying circuit is connected with an input power Vin; the first output end of the input rectifying circuit is connected with the input end of the starting circuit and used for transmitting the rectified input voltage to the starting circuit; the output end of the starting circuit is connected with an input pin VIN of the excited push-pull control chip and is used for providing starting voltage for the excited push-pull control chip; one of output pins of a push-pull control chip is connected with a second lead end of a primary winding of the transformer and used for controlling excitation and demagnetization of the transformer; a first lead end of a primary winding of the transformer is connected with an input power Vin; the second input end and the second output end of the input rectifying circuit and the grounding pin of the excited push-pull control chip are connected with an input grounding port GND; the first input end of the output rectifying circuit is connected with the third lead end of the secondary winding of the transformer, and the second input end of the output rectifying circuit is connected with the fourth lead end of the secondary winding of the transformer and used for lifting the voltage of the secondary winding of the transformer; the first output end of the output rectifying circuit is connected with the output end Vo, and the second output end of the output rectifying circuit is connected with the output grounding port GND.
Further, the input rectification circuit includes a capacitor C1; a first end of the capacitor C1 is used as a first input end and a first output end of the input rectification circuit and is respectively connected with an input power Vin and an input end of the starting circuit; the second end of the capacitor C1 is connected to the input ground port GND as the second input end and the second output end of the input rectifying circuit.
Furthermore, the high-voltage output circuit also comprises a bootstrap circuit which is used for lifting the voltage of the primary winding of the transformer; the bootstrap circuit includes: a capacitor C2 and a diode D1;
the anode of the diode D1 is used as a first input end of the bootstrap circuit and is connected with a first output end of the input rectifying circuit; the cathode of the diode D1 is connected with the first end of the capacitor C2, and the common end of the diode D1 is used as the first output end of the bootstrap circuit and is connected with the input end of the starting circuit; a second terminal of the capacitor C2 is connected to the input ground port GND as a second input terminal and a second output terminal of the bootstrap circuit.
Further, the capacitor C2 is a bootstrap capacitor having a value in the range of 1nF-47nF. The bootstrap capacitor C2 has a small capacitance value and can be charged in a short time, so that the purpose of boosting the voltage of the primary winding of the transformer is achieved, the voltage coupled to the secondary winding of the transformer is also boosted accordingly, and the effect of boosting the output voltage is further achieved.
Furthermore, the starting circuit comprises a resistor R1, and a first end of the resistor R1 is an input end of the starting circuit; the second end of the resistor R1 is the output end of the starting circuit.
Furthermore, the output rectifying circuit comprises an N-order voltage-multiplying circuit, wherein N is an integer greater than or equal to 2, and each order voltage-multiplying circuit comprises a voltage-multiplying capacitor and a voltage-multiplying diode; the first end of the voltage-multiplying capacitor is used as the first end of the voltage-multiplying circuit, the second end of the voltage-multiplying capacitor is connected with the anode of the voltage-multiplying diode and then used as the second end of the voltage-multiplying circuit, and the cathode of the voltage-multiplying diode is used as the third end of the voltage-multiplying circuit;
the first end of the first-stage voltage doubling circuit is connected with the third lead end of the secondary winding of the transformer; the third end of the first-stage voltage doubling circuit is connected with the fourth lead end of the secondary winding of the transformer, and meanwhile, the third end of the first-stage voltage doubling circuit is used as the second output end of the output rectifying circuit and is connected with the output grounding port GND;
the first end of the second-order voltage-multiplying circuit is connected with the third end of the first-order voltage-multiplying circuit; the third end of the second-order voltage-multiplying circuit is connected with the second end of the first-order voltage-multiplying circuit;
and the second end of the last-stage voltage doubling circuit is used as the first output end of the output rectifying circuit and is connected with the output end Vo.
Furthermore, the output rectifying circuit comprises an N-order voltage-multiplying circuit, wherein N is an integer greater than or equal to 2, and each order voltage-multiplying circuit comprises a voltage-multiplying capacitor and a voltage-multiplying diode; the first end of the voltage-multiplying capacitor is used as the first end of the voltage-multiplying circuit, the second end of the voltage-multiplying capacitor is connected with the cathode of the voltage-multiplying diode and then used as the second end of the voltage-multiplying circuit, and the anode of the voltage-multiplying diode is used as the third end of the voltage-multiplying circuit;
the first end of the first-stage voltage doubling circuit is connected with the third lead end of the secondary winding of the transformer; the third end of the first-order voltage doubling circuit is connected with the fourth lead end of the secondary winding of the transformer, and meanwhile, the third end of the first-order voltage doubling circuit serving as the second output end of the output rectifying circuit is connected with an output grounding port GND;
the first end of the second-order voltage-multiplying circuit is connected with the third end of the first-order voltage-multiplying circuit; the third end of the second-order voltage-multiplying circuit is connected with the second end of the first-order voltage-multiplying circuit;
and the second end of the last-stage voltage doubling circuit is used as the first output end of the output rectifying circuit and is connected with the output end Vo.
In a second aspect, there is provided a high voltage output circuit applied to an ionizer, comprising: the input rectifying circuit, the starting circuit, the excitation push-pull control chip, the transformer and the output rectifying circuit;
the input rectifying circuit comprises a capacitor C1; the starting circuit comprises a resistor R1; the driving and pushing control chip comprises an input pin VIN, a first output pin VD1, a second output pin VD2 and a grounding pin VSS; the transformer comprises a primary winding and a secondary winding, wherein the primary winding is provided with a first lead end and a second lead end, the secondary winding is provided with a third lead end and a fourth lead end, and the first lead end and the fourth lead end are homonymous ends; the output rectifying circuit comprises an N-order voltage-multiplying circuit, N is an integer greater than or equal to 2, and each order voltage-multiplying circuit comprises a voltage-multiplying capacitor and a voltage-multiplying diode; the first end of the voltage-multiplying capacitor is used as the first end of the voltage-multiplying circuit, the second end of the voltage-multiplying capacitor is connected with the anode of the voltage-multiplying diode and then used as the second end of the voltage-multiplying circuit, and the cathode of the voltage-multiplying diode is used as the third end of the voltage-multiplying circuit;
the first end of the capacitor C1 is respectively connected with the first end of the resistor R1 and the first lead end of the primary winding of the transformer, and the common end of the capacitor C1 is connected with an input power source Vin; the second end of the resistor R1 is connected with an input pin VIN of the push-pull control chip; a first output pin VD1 of a push-pull control chip is connected with a second lead end of a primary winding of a transformer; the ground pin VSS of the push-pull control chip and the second end of the capacitor C1 are both connected with the input ground port GND; the first end of the first-stage voltage doubling circuit is connected with the third lead end of the secondary winding of the transformer; the third end of the first-stage voltage doubling circuit is connected with the fourth lead end of the secondary winding of the transformer, and meanwhile, the third end of the first-stage voltage doubling circuit is used as the second output end of the output rectifying circuit and is connected with the output grounding port GND; the first end of the second-order voltage-multiplying circuit is connected with the third end of the first-order voltage-multiplying circuit; the third end of the second-order voltage-multiplying circuit is connected with the second end of the first-order voltage-multiplying circuit; and the second end of the last-stage voltage doubling circuit is used as the first output end of the output rectifying circuit and is connected with the output end Vo.
In a third aspect, there is provided a high voltage output circuit for an ionizer, comprising: the device comprises an input rectification circuit, a bootstrap circuit, a starting circuit, an excitation push-pull control chip, a transformer and an output rectification circuit;
the input rectification circuit comprises a capacitor C1; the bootstrap circuit comprises a capacitor C2 and a diode D1; the starting circuit comprises a resistor R1; the driving and pushing control chip comprises an input pin VIN, a first output pin VD1, a second output pin VD2 and a grounding pin VSS; the transformer comprises a primary winding and a secondary winding, wherein the primary winding is provided with a first lead end and a second lead end, the secondary winding is provided with a third lead end and a fourth lead end, and the first lead end and the fourth lead end are homonymous ends; the output rectifying circuit comprises N-order voltage-multiplying circuits, N is an integer greater than or equal to 2, and each-order voltage-multiplying circuit comprises a voltage-multiplying capacitor and a voltage-multiplying diode; the first end of the voltage-multiplying capacitor is used as the first end of the voltage-multiplying circuit, the second end of the voltage-multiplying capacitor is connected with the cathode of the voltage-multiplying diode and then used as the second end of the voltage-multiplying circuit, and the anode of the voltage-multiplying diode is used as the third end of the voltage-multiplying circuit;
the first end of the capacitor C1 is connected with the anode of the diode D1, and the common end of the capacitor C1 is connected with an input power Vin; the cathode of the diode D1 is respectively connected with the first end of the capacitor C2, the first end of the resistor R1 and the first lead end of the primary winding of the transformer; the second end of the resistor R1 is connected with an input pin VIN of the push-pull control chip; a first output pin VD1 of a push-pull control chip is connected with a second lead end of a primary winding of a transformer; the ground pin VSS of the push-pull control chip, the second end of the capacitor C2 and the second end of the capacitor C1 are connected with an input ground port GND; the first end of the first-stage voltage doubling circuit is connected with the third lead end of the secondary winding of the transformer; the third end of the first-order voltage doubling circuit is connected with the fourth lead end of the secondary winding of the transformer, and meanwhile, the third end of the first-order voltage doubling circuit serving as the second output end of the output rectifying circuit is connected with an output grounding port GND; the first end of the second-order voltage-multiplying circuit is connected with the third end of the first-order voltage-multiplying circuit; the third end of the second-order voltage-multiplying circuit is connected with the second end of the first-order voltage-multiplying circuit; and the second end of the last-stage voltage doubling circuit is used as the first output end of the output rectifying circuit and is connected with the output end Vo.
The utility model discloses its that adopts swashs push-pull control chip, please refer to fig. 3, including first push-pull MOS pipe, second push-pull MOS pipe to and for first push-pull MOS pipe and second push-pull MOS pipe provide driven the control unit and oscillator, first push-pull MOS pipe switches on in turn with second push-pull MOS pipe, and first drive pin VD1 and second drive pin VD2 export two way control signal. One implementation of the control chip is an SCM1209A primary side push-pull controller provided by Guangzhou Jinsheng Yang science and technology Limited; this is described in detail in the chinese utility model patent publication No. CN216981809U entitled "a start-up assist circuit, controller and push-pull converter".
For convenience of description, the pins involved are defined for it to excite the push-pull control chip U1 as follows:
VD1 foot: the first output pin is a pin connected with the drain electrode of the first push-pull MOS tube;
VD2 pin: the second output pin is a pin connected with the drain electrode of the second push-pull MOS tube;
VIN foot: the input pin is used for connecting the pin of the output end of the starting circuit;
VSS pin: and the grounding pin is used for connecting a pin of the input grounding port GND.
The theory of operation of this application will combine specific embodiment to describe, and the no longer repeated description here compares with prior art, the beneficial effects of the utility model reside in that:
1) According to the direct-current power supply control method and device, high-voltage power supply of a direct-current power supply can be achieved only by using one output pin in the push-pull control chip U1 and one primary winding of the transformer T1 to carry out push-pull work, loss caused by the fact that a push-pull triode works too long in dead zone time due to the adoption of a self-excitation push-pull scheme is avoided, and common loss among the push-pull triodes is reduced; meanwhile, the primary side of the transformer does not need to use a plurality of windings, and the size of the transformer can be reduced to a certain extent, so that the size of the whole product is reduced.
2) After a bootstrap circuit is added to the primary side of a transformer, when a first push-pull MOS tube at a port of a first output pin VD1 of a push-pull control chip is switched off, the voltage at two ends of a junction capacitor of the first push-pull MOS tube at the moment of switching off is Vin + NVo, due to leakage inductance on the transformer T1 and the existence of the junction capacitor of the first push-pull MOS tube in the push-pull control chip U1 and a diode D1, generated resonant voltage current charges a capacitor C2, and due to the fact that the capacitance value of the capacitor C2 is small, the voltage can be increased to a higher voltage in a short time, and further voltage at two ends of a primary side winding of the transformer T1 is increased when the next period comes, energy transmitted to a secondary side through winding coupling is increased, and output voltage is further increased after the output rectification circuit at the rear end. This application only through increasing a electric capacity and a diode, can further promote output voltage, circuit structure is simple, and can effectively reduce high-voltage output circuit's volume, improve work efficiency.
Drawings
FIG. 1 is a schematic circuit diagram of a prior art;
fig. 2 is a schematic circuit diagram of a first embodiment of the present invention;
fig. 3 is a schematic circuit diagram of a second embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a third embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a fourth embodiment of the present invention;
fig. 6 is an internal logic block diagram of the push-pull control chip adopted by the present invention;
fig. 7 is a simplified circuit schematic of a first embodiment of the present invention;
fig. 8 is a simplified circuit schematic of a second embodiment of the present invention;
fig. 9 is a simplified circuit schematic of a third embodiment of the present invention;
fig. 10 is a simplified circuit schematic diagram of a fourth embodiment of the present invention.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below, and it is apparent that the described embodiments are some, not all embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort shall fall within the protection scope of the present application.
It is to be noted that the terms "comprises" and "comprising," and any variations thereof, as used in the specification and claims of this application, are intended to cover non-exclusive inclusions, such as, for example, the inclusion of a list of elements or unit circuits is not necessarily limited to those elements or unit circuits expressly listed, but may include elements or unit circuits not expressly listed or inherent to such circuits.
First embodiment
Referring to fig. 2, a high voltage output circuit is provided, which includes an input rectification circuit, a start circuit, a push-pull control chip U1, a transformer T1, and an output rectification circuit;
the first input end of the input rectifying circuit is connected with an input power Vin; the first output end of the input rectifying circuit is connected with the input end of the starting circuit and used for transmitting the rectified input voltage to the starting circuit; the output end of the starting circuit is connected with an input pin VIN of the excitation push-pull control chip U1 and is used for providing starting voltage for the excitation push-pull control chip U1; one of output pins of a push-pull control chip U1 is connected with a second lead end of a primary winding of a transformer T1 and used for controlling excitation and demagnetization of the transformer T1, when the output pin outputs a high level, the transformer T1 is excited, and when the output pin outputs a low level, the transformer T1 is demagnetized; a first lead end of a primary winding of the transformer T1 is connected with an input power Vin; the second input end and the second output end of the input rectifying circuit and a grounding pin VSS of the excitation push-pull control chip U1 are connected with an input grounding port GND; the first input end of the output rectifying circuit is connected with the third lead end of the secondary winding of the transformer T1, and the second input end of the output rectifying circuit is connected with the fourth lead end of the secondary winding of the transformer T1, so as to lift the voltage of the secondary winding of the transformer T1; the first output end of the output rectifying circuit is connected with the output end Vo, and the second output end of the output rectifying circuit is connected with the output grounding port GND.
As an embodiment of the input rectification circuit, the input rectification circuit includes a capacitor C1;
as a specific embodiment of the starting circuit, the starting circuit includes a resistor R1;
as a specific embodiment of the output rectification circuit, the output rectification circuit comprises N-order voltage-multiplying circuits, where N is an integer greater than or equal to 2, and each order voltage-multiplying circuit comprises a voltage-multiplying capacitor and a voltage-multiplying diode; the first end of the voltage-multiplying capacitor is used as the first end of the voltage-multiplying circuit, the second end of the voltage-multiplying capacitor is connected with the anode of the voltage-multiplying diode and then used as the second end of the voltage-multiplying circuit, and the cathode of the voltage-multiplying diode is used as the third end of the voltage-multiplying circuit; the first end of the first-stage voltage doubling circuit is connected with the third lead end of the secondary winding of the transformer; the third end of the first-stage voltage doubling circuit is connected with the fourth lead end of the secondary winding of the transformer, and meanwhile, the third end of the first-stage voltage doubling circuit is used as the second output end of the output rectifying circuit and is connected with the output grounding port GND; the first end of the second-order voltage-multiplying circuit is connected with the third end of the first-order voltage-multiplying circuit; the third end of the second-order voltage-multiplying circuit is connected with the second end of the first-order voltage-multiplying circuit; and the second end of the last-stage voltage doubling circuit is used as the first output end of the output rectifying circuit and is connected with the output end Vo.
In the present embodiment, please refer to fig. 7, the output rectifying circuit takes a second-order standard CW voltage doubling circuit and a negative voltage output connection as an example to explain the present embodiment in detail.
In the embodiment, the fixed duty ratio of the push-pull control chip U1 is 0.5, and the frequency is 260Khz; the related pins comprise an input pin VIN, a first output pin VD1 and a grounding pin VSS; the transformer T1 comprises a primary winding and a secondary winding, wherein the primary winding is provided with a first lead terminal 1 and a second lead terminal 2, the secondary winding is provided with a third lead terminal 3 and a fourth lead terminal 4, and the first lead terminal 1 and the fourth lead terminal 4 are homonymous terminals; the output rectifying circuit comprises a capacitor C3, a capacitor C4, a diode D2 and a diode D3;
the first end of the capacitor C1 is respectively connected with the first end of the resistor R1 and the first lead end of the primary winding of the transformer T1, and the common end of the capacitor C1 is connected with an input power Vin; the second end of the resistor R1 is connected with an input pin VIN of the push-pull control chip U1; a first output pin VD1 of a push-pull control chip U1 is connected with a second lead end of a primary winding of a transformer T1; the ground pin VSS of the push-pull control chip U1 and the second end of the capacitor C1 are both connected with the input ground port GND; a third lead end of a secondary winding of the transformer T1 is connected with a first end of the capacitor C3; the second end of the capacitor C3 is respectively connected with the anode of the diode D2 and the cathode of the diode D3; the cathode of the diode D2 is respectively connected with the fourth lead end of the secondary winding of the transformer T1, the first end of the capacitor C4 and the output ground port GND; and the second end of the capacitor C4 is connected with the anode of the diode D3 and then is connected with the output port Vo. The input ground port GND and the output ground port GND are both 0V, and are the same point in the electrical connection.
The working principle of the embodiment is as follows:
referring to fig. 6 and 7, in the first working state, when the internal clock signal of the push-pull control chip U1 is driven to a low level by the first push-pull MOS switch tube, the first push-pull MOS switch tube is turned off, and at this time, lenz's law may indicate that the second lead terminal of the primary winding of the transformer T1 is positive, and the third lead terminal of the secondary winding of the transformer T1 corresponding to the second lead terminal is positive, which are terminals of the same name. At this stage, the flyback energy of the transformer T1 supplies energy to the secondary side, and the flyback energy is not limited by the turn ratio of the transformer T1 and is larger than the energy during forward excitation to a certain extent, so that the output voltage is raised to be higher. Because the induced voltage of the third lead terminal of the secondary winding of the transformer T1 is positive at this time, the diode D2 in the output rectifying circuit is turned on, and the loop through which the voltage passes is: the third lead end of the secondary winding of the transformer T1 → the capacitor C3 → the diode D2 → the fourth lead end of the secondary winding of the transformer T1; the secondary winding of the transformer T1 charges the capacitor C3 at this time.
In the second working state, when the internal clock signal of the push-pull control chip U1 is excited to provide a high level for the first push-pull MOS switch tube, the first push-pull MOS switch tube is conducted, and a primary side loop is generated as follows: the input power source Vin → the capacitor C1 → the first lead end of the primary winding of the transformer T1 → the second lead end of the primary winding of the transformer T1 → the first output pin VD1 of the push-pull control chip U1 → the input grounding port GND; the other branch circuit supplies power to the push-pull control chip U1 through an input power source Vin → the resistor R1 → the input pin VIN of the push-pull control chip U1. At the moment, the primary winding of the transformer T1 is excited, the Lenz law can deduce that the first lead end of the primary winding of the transformer T1 is positive, the electromagnetic induction law deduces that the fourth lead end of the secondary winding of the transformer T1 is positive, and the first lead end and the fourth lead end are homonymous ends. At this time, the voltage at two ends of the primary winding of the transformer T1 is Vin, the current of the primary winding of the transformer T1 linearly rises, the drain-source voltage of a first push-pull MOS tube in the push-pull control chip U1 is approximate to 0V, the voltage at two ends of the secondary winding of the transformer T1 is Vin/N, wherein N is the turn ratio of the primary winding and the secondary winding of the transformer T1, and the forward energy of the transformer T1 supplies energy to the secondary side. On the secondary side of the transformer T1, since the induced voltage at the fourth lead terminal of the secondary winding of the transformer T1 is also positive, the diode D3 is turned on; because the secondary winding of the transformer T1 is charged with the capacitor C3 in the first working state, according to the characteristic that the capacitor does not suddenly change in a short time, the potential of the side, connected with the third lead end of the transformer T1, of the capacitor C3 is positive at this stage, and at the moment, the secondary winding of the transformer T1 and the capacitor C3 are charged into the capacitor C4 together, so that voltage-multiplying output is realized.
Second embodiment
The second optimized implementation manner provided by the present application is as shown in fig. 3, and the main difference between the present embodiment and the first embodiment lies in the connection manner of the voltage doubling circuit in the output rectification circuit;
as a specific embodiment of the output rectification circuit, the output rectification circuit comprises N-order voltage-multiplying circuits, where N is an integer greater than or equal to 2, and each order voltage-multiplying circuit comprises a voltage-multiplying capacitor and a voltage-multiplying diode; the first end of the voltage-multiplying capacitor is used as the first end of the voltage-multiplying circuit, the second end of the voltage-multiplying capacitor is connected with the cathode of the voltage-multiplying diode and then used as the second end of the voltage-multiplying circuit, and the anode of the voltage-multiplying diode is used as the third end of the voltage-multiplying circuit;
the first end of the first-stage voltage doubling circuit is connected with the third lead end of the secondary winding of the transformer T1; the third end of the first-stage voltage doubling circuit is connected with the fourth lead end of the secondary winding of the transformer T1, and meanwhile, the third end of the first-stage voltage doubling circuit is used as the second output end of the output rectifying circuit and is connected with the output grounding port GND; the first end of the second-order voltage-multiplying circuit is connected with the third end of the first-order voltage-multiplying circuit; the third end of the second-order voltage-multiplying circuit is connected with the second end of the first-order voltage-multiplying circuit; and the second end of the last-order voltage doubling circuit is used as the first output end of the output rectifying circuit and is connected with the output end Vo.
This embodiment will explain this scheme in detail by taking a second-order standard CW voltage-doubling circuit and a positive voltage output connection as an example, as shown in fig. 8; other circuit structures in this embodiment are similar to those in the first embodiment, and are not described herein again.
A third lead end of a secondary winding of the transformer T1 is connected with a first end of the capacitor C3; the second end of the capacitor C3 is respectively connected with the cathode of the diode D2 and the anode of the diode D3; the anode of the diode D2 is respectively connected with the fourth lead end of the secondary winding of the transformer T1, the first end of the capacitor C4 and the output ground port GND; and the second end of the capacitor C4 is connected with the cathode of the diode D3 and then connected with the output port Vo.
The working principle of the present embodiment is also similar to that of the first embodiment, and the main difference is that the loop of the output rectifying circuit is different;
in a first working state, when an internal clock signal of a push-pull control chip U1 is excited by the first working state to supply a high level to a first push-pull MOS switching tube, the first push-pull MOS switching tube is conducted, and a first lead end of a primary winding of a transformer T1 and a fourth lead end of a secondary winding are positive; diode D2 is turned on, and the secondary side loop of transformer T1 is: the fourth lead end of the secondary winding of the transformer T1 → the diode D2 → the capacitor C3 → the third lead end of the secondary winding of the transformer T1; the secondary winding of the transformer T1 charges the capacitor C3 at this time.
In a second working state, when the internal clock signal of the push-pull control chip U1 is excited by the first push-pull MOS switch tube to supply a low level to the first push-pull MOS switch tube, the first push-pull MOS switch tube is switched off, and the second lead end of the primary winding of the transformer T1 and the third lead end of the secondary winding are positive; diode D3 is turned on, and the secondary side loop of transformer T1 is: the third lead end of the secondary winding of the transformer T1 → the capacitor C3 → the diode D3 → the capacitor C4 → the fourth lead end of the secondary winding of the transformer T1; at this time, the secondary winding of the transformer T1 and the capacitor C3 charge the capacitor C4 together, so that voltage-doubling output is realized.
Third embodiment
A third optimized implementation manner provided by the present application is shown in fig. 4 and fig. 9, in this embodiment, in order to further increase the output voltage, the present embodiment is optimized based on the first embodiment, and the main difference from the first embodiment is that a bootstrap circuit is added to the primary side of the transformer T1.
As a specific embodiment of the bootstrap circuit, the bootstrap circuit includes a capacitor C2 and a diode D1; the anode of the diode D1 is used as a first input end of the bootstrap circuit and is connected with a first output end of the input rectifying circuit; the cathode of the diode D1 is connected with the first end of the capacitor C2, and the common end of the diode D1 is used as the first output end of the bootstrap circuit and is connected with the input end of the starting circuit; a second terminal of the capacitor C2 is connected to the input ground port GND as a second input terminal and a second output terminal of the bootstrap circuit.
In the embodiment, the capacitor C2 is a bootstrap circuit, and has a small capacitance value, which is generally in a range of 1nF to 47nF; because the capacitance value is small, the charging can be completed in a short time, so that the purpose of lifting the voltage of the primary winding of the transformer T1 is achieved, the voltage coupled to the secondary winding of the transformer T1 is also lifted, and the effect of lifting the output voltage is further achieved.
The other circuit structures of the present invention are similar to those of the first embodiment, and are not described herein;
the second operating state of the operating principle of this embodiment is the same as the first embodiment, and the difference is mainly the first operating state, which is specifically as follows:
in the first working state, when an internal clock signal of the push-pull control chip U1 is excited by the first working state to supply a low level to the first push-pull MOS tube, the first push-pull MOS switch tube is switched off, at the moment, the second lead end of the primary winding of the transformer T1 is positive, the third lead end of the corresponding secondary winding is positive, and the two lead ends are homonymous; at this stage, the drain-source voltage of a first push-pull MOS switch tube in the push-pull control chip U1 is Vin + NVo, wherein N is the turn ratio of the primary winding and the secondary winding of the transformer T1. Because the transformer T1 has a leakage inductance Lk and generates resonance with a junction capacitor Coss of the first push-pull MOS switching tube, the flyback energy of the transformer T1 is a secondary side function at the moment, and the existence of the diode D1 can effectively prevent the current generated in the primary side loop from flowing backwards; the primary side loop at this time is: the first output pin VD1 of the push-pull control chip U1 → the second lead end of the primary winding of the transformer T1 → the first lead end of the primary winding of the transformer T1 → the capacitor C2 → the input grounding port GND, and because the capacitance value of the capacitor C2 is small, the voltage can be raised in a short time, and temporarily in the next period, the voltage can act on the primary winding of the transformer T1, so that the voltage of the primary winding is raised higher, that is, the voltage coupled to the secondary side through the transformer T1 is raised along with the voltage, and the output voltage is further improved.
Fourth embodiment
A fourth optimized implementation manner provided by the present application is as shown in fig. 4 and fig. 9, and the main difference between the present embodiment and the third embodiment is the connection manner of the voltage doubling circuit in the output rectification circuit; the connection mode of the voltage doubling circuit in the embodiment is the same as that of the second embodiment, and is a positive voltage output connection method; the implementation optimization of this embodiment is actually a combination of the second embodiment and the third embodiment, a bootstrap circuit is added on the primary side of the transformer T1, and the voltage-doubling rectifying circuit on the secondary side of the transformer T1 adopts a connection method of positive voltage output, and details of the circuit structure and the operating principle of this embodiment are not repeated herein.
In view of the foregoing, it is to be noted that the above-mentioned preferred embodiments should not be considered as limitations of the present invention, and it will be apparent to those skilled in the art that various modifications and decorations can be made without departing from the spirit and scope of the present invention.
Claims (9)
1. A high-voltage output circuit is characterized by comprising an input rectifying circuit, a starting circuit, a push-pull control chip, a transformer and an output rectifying circuit;
the first input end of the input rectifying circuit is connected with an input power Vin; the first output end of the input rectifying circuit is connected with the input end of the starting circuit and used for transmitting the rectified input voltage to the starting circuit; the output end of the starting circuit is connected with an input pin VIN of the other excitation push-pull control chip and is used for providing starting voltage for the other excitation push-pull control chip; one of the output pins of the excitation push-pull control chip is connected with the second lead end of the primary winding of the transformer and used for controlling excitation and demagnetization of the transformer, when the output pin outputs a high level, the transformer is excited, and when the output pin outputs a low level, the transformer is demagnetized; a first lead end of a primary winding of the transformer is connected with the input power Vin; the second input end and the second output end of the input rectifying circuit and the grounding pin VSS of the other excitation push-pull control chip are connected with an input grounding port GND; the first input end of the output rectifying circuit is connected with the third lead end of the secondary winding of the transformer, and the second input end of the output rectifying circuit is connected with the fourth lead end of the secondary winding of the transformer, so as to lift the voltage of the secondary winding of the transformer; and a first output end of the output rectifying circuit is connected with the output end Vo, and a second output end of the output rectifying circuit is connected with the output grounding port GND.
2. The high voltage output circuit according to claim 1, wherein the input rectification circuit comprises a capacitor C1; a first end of the capacitor C1 is used as a first input end and a first output end of the input rectifying circuit and is respectively connected with the input power Vin and the input end of the starting circuit; and the second end of the capacitor C1 is used as the second input end and the second output end of the input rectifying circuit and is connected with the input grounding port GND.
3. The high-voltage output circuit according to claim 1, wherein the high-voltage output circuit further comprises a bootstrap circuit for boosting the voltage of the primary winding of the transformer; the bootstrap circuit includes: a capacitor C2 and a diode D1;
the anode of the diode D1 is used as a first input end of the bootstrap circuit and is connected with a first output end of the input rectification circuit; the cathode of the diode D1 is connected with the first end of the capacitor C2, and the common end of the diode D1 is used as the first output end of the bootstrap circuit and is connected with the input end of the starting circuit; a second end of the capacitor C2 is connected to the input ground port GND as a second input end and a second output end of the bootstrap circuit.
4. The high-voltage output circuit as claimed in claim 3, wherein the capacitor C2 is a bootstrap capacitor having a value in the range of 1nF to 47nF.
5. The high-voltage output circuit as claimed in claim 1, wherein the start-up circuit comprises a resistor R1, a first terminal of the resistor R1 being an input terminal of the start-up circuit; the second end of the resistor R1 is the output end of the starting circuit.
6. The high-voltage output circuit according to any one of claims 1 to 5, wherein the output rectifying circuit comprises an N-order voltage-multiplying circuit, N is an integer greater than or equal to 2, and each order voltage-multiplying circuit comprises a voltage-multiplying capacitor and a voltage-multiplying diode; the first end of the voltage-multiplying capacitor is used as the first end of the voltage-multiplying circuit, the second end of the voltage-multiplying capacitor is connected with the anode of the voltage-multiplying diode and then used as the second end of the voltage-multiplying circuit, and the cathode of the voltage-multiplying diode is used as the third end of the voltage-multiplying circuit;
the first end of the voltage doubling circuit of the first stage is connected with the third lead end of the secondary winding of the transformer; a third end of the voltage doubling circuit of the first stage is connected with a fourth lead end of the secondary winding of the transformer, and is also used as a second output end of the output rectifying circuit to be connected with an output grounding port GND;
the first end of the voltage doubling circuit of the next stage is connected with the third end of the voltage doubling circuit of the previous stage; the third end of the voltage-multiplying circuit of the next stage is connected with the second end of the voltage-multiplying circuit of the previous stage;
and the second end of the voltage doubling circuit in the last stage is used as the first output end of the output rectifying circuit and is connected with the output end Vo.
7. The high-voltage output circuit according to any one of claims 1 to 5, wherein the output rectifying circuit comprises an N-order voltage-multiplying circuit, N is an integer greater than or equal to 2, and each order voltage-multiplying circuit comprises a voltage-multiplying capacitor and a voltage-multiplying diode; the first end of the voltage-multiplying capacitor is used as the first end of the voltage-multiplying circuit, the second end of the voltage-multiplying capacitor is connected with the cathode of the voltage-multiplying diode and then used as the second end of the voltage-multiplying circuit, and the anode of the voltage-multiplying diode is used as the third end of the voltage-multiplying circuit;
the first end of the voltage doubling circuit of the first stage is connected with the third lead end of the secondary winding of the transformer; a third end of the voltage doubling circuit of the first stage is connected with a fourth lead end of the secondary winding of the transformer, and is also used as a second output end of the output rectifying circuit to be connected with an output grounding port GND;
the first end of the voltage doubling circuit of the next stage is connected with the third end of the voltage doubling circuit of the previous stage; the third end of the voltage-multiplying circuit of the next stage is connected with the second end of the voltage-multiplying circuit of the previous stage;
and the second end of the voltage doubling circuit in the last stage is used as the first output end of the output rectifying circuit and is connected with the output end Vo.
8. A high voltage output circuit for an ionizer, the high voltage output circuit comprising: the input rectifying circuit, the starting circuit, the excitation push-pull control chip, the transformer and the output rectifying circuit;
the input rectifying circuit comprises a capacitor C1; the starting circuit comprises a resistor R1; the driving push-pull control chip comprises an input pin VIN, a first output pin VD1, a second output pin VD2 and a grounding pin VSS; the transformer comprises a primary winding and a secondary winding, the primary winding is provided with a first lead terminal and a second lead terminal, the secondary winding is provided with a third lead terminal and a fourth lead terminal, and the first lead terminal and the fourth lead terminal are homonymy terminals; the output rectifying circuit comprises an N-order voltage-multiplying circuit, N is an integer greater than or equal to 2, and each order voltage-multiplying circuit comprises a voltage-multiplying capacitor and a voltage-multiplying diode; the first end of the voltage-multiplying capacitor is used as the first end of the voltage-multiplying circuit, the second end of the voltage-multiplying capacitor is connected with the anode of the voltage-multiplying diode and then used as the second end of the voltage-multiplying circuit, and the cathode of the voltage-multiplying diode is used as the third end of the voltage-multiplying circuit;
the first end of the capacitor C1 is respectively connected with the first end of the resistor R1 and the first lead end of the primary winding of the transformer, and the common end of the capacitor C1 is connected with an input power source Vin; the second end of the resistor R1 is connected with an input pin VIN of the other excitation push-pull control chip; a first output pin VD1 of the excitation push-pull control chip is connected with a second lead end of the primary winding of the transformer; the ground pin VSS of the push-pull control chip and the second end of the capacitor C1 are both connected with the input ground port GND; the first end of the voltage doubling circuit of the first stage is connected with the third lead end of the secondary winding of the transformer; a third end of the voltage doubling circuit of the first stage is connected with a fourth lead end of the secondary winding of the transformer, and is also used as a second output end of the output rectifying circuit to be connected with an output grounding port GND; the first end of the voltage-multiplying circuit of the next stage is connected with the third end of the voltage-multiplying circuit of the previous stage; the third end of the voltage-multiplying circuit of the next stage is connected with the second end of the voltage-multiplying circuit of the previous stage; and the second end of the voltage doubling circuit in the last stage is used as the first output end of the output rectifying circuit and is connected with the output end Vo.
9. A high voltage output circuit for an ionizer, the high voltage output circuit comprising: the device comprises an input rectification circuit, a bootstrap circuit, a starting circuit, an excitation push-pull control chip, a transformer and an output rectification circuit;
the input rectifying circuit comprises a capacitor C1; the bootstrap circuit comprises a capacitor C2 and a diode D1; the starting circuit comprises a resistor R1; the driving push-pull control chip comprises an input pin VIN, a first output pin VD1, a second output pin VD2 and a grounding pin VSS; the transformer comprises a primary winding and a secondary winding, the primary winding is provided with a first lead terminal and a second lead terminal, the secondary winding is provided with a third lead terminal and a fourth lead terminal, and the first lead terminal and the fourth lead terminal are homonymy terminals; the output rectifying circuit comprises an N-order voltage-multiplying circuit, N is an integer greater than or equal to 2, and each order voltage-multiplying circuit comprises a voltage-multiplying capacitor and a voltage-multiplying diode; the first end of the voltage-multiplying capacitor is used as the first end of the voltage-multiplying circuit, the second end of the voltage-multiplying capacitor is connected with the cathode of the voltage-multiplying diode and then used as the second end of the voltage-multiplying circuit, and the anode of the voltage-multiplying diode is used as the third end of the voltage-multiplying circuit;
the first end of the capacitor C1 is connected with the anode of the diode D1, and the common end of the capacitor C1 is connected with an input power Vin; the cathode of the diode D1 is respectively connected with the first end of the capacitor C2, the first end of the resistor R1 and the first lead end of the primary winding of the transformer; the second end of the resistor R1 is connected with an input pin VIN of the other excitation push-pull control chip; a first output pin VD1 of the excitation push-pull control chip is connected with a second lead end of the primary winding of the transformer; a grounding pin VSS of the excited push-pull control chip, a second end of the capacitor C2 and a second end of the capacitor C1 are connected with the input grounding port GND; a first end of the voltage doubling circuit of the first stage is connected with a third lead end of the secondary winding of the transformer; the third end of the voltage doubling circuit of the first stage is connected with the fourth lead end of the secondary winding of the transformer, and meanwhile, the third end of the voltage doubling circuit serving as the second output end of the output rectifying circuit is connected with an output grounding port GND; the first end of the voltage doubling circuit of the next stage is connected with the third end of the voltage doubling circuit of the previous stage; the third end of the voltage-multiplying circuit of the next stage is connected with the second end of the voltage-multiplying circuit of the previous stage; and the second end of the voltage doubling circuit in the last stage is used as the first output end of the output rectifying circuit and is connected with the output end Vo.
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| CN202222614707.4U CN218850636U (en) | 2022-09-30 | 2022-09-30 | High-voltage output circuit |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN118074535A (en) * | 2024-04-15 | 2024-05-24 | 杭州飞仕得科技股份有限公司 | Push-pull switching power supply circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN118074535A (en) * | 2024-04-15 | 2024-05-24 | 杭州飞仕得科技股份有限公司 | Push-pull switching power supply circuit |
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