CN109217655B - Power supply capable of prolonging maintenance time after power failure - Google Patents
Power supply capable of prolonging maintenance time after power failure Download PDFInfo
- Publication number
- CN109217655B CN109217655B CN201710514503.4A CN201710514503A CN109217655B CN 109217655 B CN109217655 B CN 109217655B CN 201710514503 A CN201710514503 A CN 201710514503A CN 109217655 B CN109217655 B CN 109217655B
- Authority
- CN
- China
- Prior art keywords
- capacitor
- terminal
- controller
- power supply
- power
- 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
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/0096—Means for increasing hold-up time, i.e. the duration of time that a converter's output will remain within regulated limits following a loss of input power
Abstract
The invention discloses a power supply capable of prolonging the maintenance time after power failure, which comprises a direct current/direct current power supply converter, a maintenance time control circuit, a second capacitor and a controller, wherein the maintenance time control circuit is provided with a first capacitor, a first resistor and an electronic switch; when the controller judges that the power is not off, the controller controls the electronic switch to be open; when the controller judges that the power is cut off, the controller conducts the electronic switch, and the first capacitor and the second capacitor are jointly discharged to the input side of the direct current/direct current power supply converter.
Description
Technical Field
The present invention relates to a power supply, and more particularly to a power supply capable of prolonging the power-off duration.
Background
The conventional power supply mainly includes an ac/dc power conversion circuit, a power factor correction circuit and a dc/dc power converter, wherein an input side of the ac/dc power conversion circuit receives an ac power, and an output side of the dc/dc power converter is connected to a load. Through the cooperation of the AC/DC power conversion circuit, the power factor correction circuit and the DC/DC power converter, the AC power is subjected to DC conversion and power factor correction, so that a DC power is output to the load at the output side of the DC/DC power converter, and meanwhile, the DC power stores energy in an input capacitor of the load.
When the conventional power supply suddenly stops outputting the dc power, such as a sudden shutdown or a sudden power jump of the ac power, the load performs an emergency processing procedure (e.g., data backup or shutdown …, etc.) because it does not receive the dc power, and the input capacitor of the load releases the stored energy. The voltage of the input capacitor is gradually reduced along with the continuous release of stored energy, and when the load detects that the voltage of the input capacitor is lower than a reference voltage, the load is directly closed. Here, a duration from when the load does not receive the dc power to when the terminal voltage of the input capacitor is lower than the reference voltage is referred to as a hold-up time (hold-up time). Obviously, when the load is shut down, if the emergency processing procedure is not completed, the load may be shut down abnormally, resulting in bad results (e.g., data loss).
In order to allow the power supply to have enough time for the load to perform the emergency processing procedure after the ac power source is suddenly powered off, the power supply itself is usually required to provide enough time for the load to maintain after the ac power source is suddenly powered off. Conventionally, the holding time is provided by using a large-capacity capacitor as an output capacitor on the output side of the dc/dc power converter, or by using a large-capacity capacitor as a capacitor (Bulk capacitor) connected between the power factor correction circuit and the dc/dc power converter. The capacitor with large capacity is used for releasing the stored energy to the input capacitor of the load after the AC power supply is cut off, thereby delaying the discharge of the input capacitor and prolonging the holding time. However, the use of a large-capacity capacitor is not only more costly and bulky, but also causes inconvenience in the design of the entire mechanism of the power supply system, and the use of a large-capacity capacitor only for the purpose of achieving the limited effect of temporarily prolonging the holding time is not cost-effective.
As can be seen from the foregoing, in order to provide a long sustain time, it is necessary to have a sufficient capacitance, but it is relatively undesirable that the capacitance is large in volume and occupies a space. To solve the above-mentioned problems, a Hold-time extension circuit (Hold-up-time extension circuits) disclosed in U.S. Pat. No. 6,504,497 is proposed, in which an output terminal of a rectifier is connected to an input terminal of a dc/dc converter through a diode, an output capacitor is connected across between a cathode terminal of the diode and a ground terminal, an anode terminal of the diode is connected to an auxiliary capacitor, an anode terminal of the auxiliary capacitor is connected to a Hold-time extension circuit, and an output terminal of the Hold-time extension circuit is connected to the input terminal of the dc/dc converter. After the voltage of the output capacitor is lower than a set value, the auxiliary capacitor starts to discharge to the maintaining time prolonging circuit, the energy is continuously provided for the direct current/direct current converter after the conversion of the maintaining time prolonging circuit, and the voltage level of the output capacitor is maintained to prolong the maintaining time.
However, in the above U.S. publication, although the output capacitor and the auxiliary capacitor are in parallel connection under the normal power supply condition, because a diode exists between the output capacitor and the auxiliary capacitor, a diode forward conduction voltage difference (about 0.7V) exists between the output capacitor and the auxiliary capacitor, and this voltage difference makes the output capacitor still have to bear the larger ripple current generated in the previous stage, so that the life of the output capacitor is reduced, i.e. in the normal state of the ac power supply, the auxiliary capacitor cannot bear the ripple current with the output capacitor on average, so that the life of the output capacitor is shorter and is easy to be damaged in advance, thereby reducing the working life of the power supply.
Disclosure of Invention
Accordingly, the present invention is directed to a power supply capable of prolonging a holding time after power-off, wherein the holding time can be effectively prolonged without using a capacitor with larger capacity.
The power supply capable of prolonging the maintenance time after power failure comprises:
a DC/DC power converter including an input side and an output side;
a hold-up time control circuit connected to the input side of the DC/DC power converter, comprising:
a first capacitor connected to the input side of the DC/DC power converter;
a first resistor connected in series with the first capacitor; and
an electronic switch connected in series with the first capacitor and the first resistor;
a second capacitor connected in parallel to the sustain time control circuit, wherein the withstand voltage of the first capacitor is smaller than that of the second capacitor; and
and the controller is connected with the maintaining time control circuit and the second capacitor, controls the electronic switch to be open when the controller judges that the input side of the DC/DC power converter is not powered off, and conducts the electronic switch when the controller judges that the input side of the DC/DC power converter is powered off, so that the first capacitor and the second capacitor discharge to the input side of the DC/DC power converter together.
According to the power supply capable of prolonging the holding time after power failure, the output side of the direct current/direct current power converter is connected with the input capacitor of the load. After the AC power supply is suddenly cut off, the controller conducts the electronic switch, the first capacitor and the second capacitor are jointly discharged to the input side of the DC/DC power supply converter, the DC/DC power supply converter can carry out voltage conversion, the output side of the DC/DC power supply converter keeps outputting the DC power supply to the input capacitor of the load, the voltage of the end of the input capacitor can be kept for a period of time and then decreased gradually, or decreased gradually at a slower speed, and further the maintenance time is relatively prolonged, so that the emergency processing program after the power off is carried out.
Furthermore, when the power supply is in normal operation, although the second capacitor bears the voltage fluctuation range of the input side of the DC/DC power converter, the electronic switch is in an open circuit state, so that the first capacitor does not need to be considered to bear the voltage fluctuation, and the capacity and voltage withstanding characteristic of the first capacitor can be smaller than those of the second capacitor, so that the holding time can be effectively prolonged on the premise of not changing to a capacitor with larger capacity.
Drawings
FIG. 1: the invention can prolong the circuit structure of the power supply with the maintenance time after power failure.
FIG. 2: the circuit diagram of the embodiment of the power supply of the invention is shown in the first embodiment.
FIG. 3: the circuit diagram of the embodiment of the power supply of the Invention Is (II).
FIG. 4: the invention discloses a timing diagram of a power supply.
FIG. 5: fig. 3 is a schematic diagram of the first discharge path and the second discharge path according to the embodiment.
FIG. 6: the circuit diagram of the embodiment of the power supply of the invention is (III).
Detailed Description
The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.
Referring to fig. 1 and 2, the power supply capable of prolonging the retention time after power-off according to the present invention includes a dc/dc power converter 10, a retention time control circuit 20 having a first capacitor Ca, a first resistor Ra and an electronic switch Qx, a second capacitor Cb and a controller 40. It should be noted that the dc/dc power converter 10 includes an input side and an output side, the input side can be connected to a reverse-flow prevention protection circuit 50, and the input side of the reverse-flow prevention protection circuit 50 can be further connected to an ac/dc power conversion circuit (not shown) and a power factor correction circuit (not shown) …, etc. to receive an input voltage V of dcINWhich is common knowledge in the field of power supply technology, will not be described in detail herein. In short, the input side of the ac/dc power converter circuit receives an ac power, and the output side of the dc/dc power converter 10 is connected to a load 60. Through the cooperation of the ac/dc power conversion circuit, the power factor correction circuit and the dc/dc power converter 10, the ac power is converted into dc power and corrected into power factor, so as to output a dc power V at the output side of the dc/dc power converter 10OUTTo the load 60 and, at the same time, the DC power supply VOUTThe input capacitor of the load 60 is charged with energy.
Referring to fig. 1 and 2, the hold-up time control circuit 20 is connected to the input side of the dc/dc power converter 10, and in addition to the first capacitor Ca, the first resistor Ra and the electronic switch Qx, the hold-up time control circuit 20 may further include a bypass device 21. The first capacitor Ca is connected to the input side of the dc/dc power converter 10, the first resistor Ra is connected in series to the first capacitor Ca, a series node n is provided between the first resistor Ra and the first capacitor Ca, and the electronic switch Qx is connected in series to the first capacitor Ca and the first resistor Ra. Specifically, the input side of the dc/dc power converter 10 has a power terminal 11 and a ground terminal 12. One end of the first capacitor Ca is connected to the power terminal 11, one end of the electronic switch Qx is connected to the ground terminal 12, and the first resistor Ra is connected between the first capacitor Ca and the electronic switch Qx. The bypass element 21 may be connected between the series node n and the ground terminal 12.
Referring to fig. 1 and 2, the second capacitor Cb is connected in parallel to the hold-time control circuit 20, such that two ends of the second capacitor Cb are respectively connected to the power source terminal 11 and the ground terminal 12 of the dc/dc power converter 10. In an embodiment of the present invention, the inrush current suppression circuit 30 may further include a surge current (inrush current) suppression circuit 30, where the surge current suppression circuit 30 includes the second capacitor Cb, a second resistor Rb and a switch Qz, the switch Qz is connected between the ground terminal 12 and the output side of the reverse current protection circuit 50, the second resistor Rb is connected in parallel to the switch Qz, and the controller 40 is connected to a control terminal of the switch Qz. The inrush current suppression circuit 30 is a typical circuit, and the operation principle thereof is not described in detail here.
Referring to fig. 1, the controller 40 is connected to the time keeping control circuit 20 and the second capacitor Cb, and in the embodiment shown in fig. 2, the controller 40 is connected to the electronic switch Qx, the switch Qz, the power source terminal 11 and the series node n, and is capable of detecting a terminal voltage of the first capacitor Ca (i.e., a voltage difference between the power source terminal 11 and the series node n) and a terminal voltage of the second capacitor Cb (i.e., a voltage difference between the power source terminal 11 and the ground terminal 12). When the controller 40 determines that the input side of the dc/dc power converter 10 is powered off, the controller 40 turns on the electronic switch Qx, and the first capacitor Ca and the second capacitor Cb discharge the electric current to the input side of the dc/dc power converter 10 together, so that the dc/dc power converter 10 can continue to perform voltage conversion to output the dc power VOUTThe voltage across the input capacitor of the load 60 is maintained for a period of time before decreasing, or at a slower rate, to extend the hold time. Wherein, as shown in fig. 3, the controller 40 can be connected to the input side of the reverse-flow protection circuit 50 to detect whether there is an input voltage VINTo determine whether the input side of the DC/DC power converter 10 is powered off; alternatively, the controller 40 may detect the terminal voltage of the second capacitor Cb to detectWhen the terminal voltage of the second capacitor Cb is determined to be lower than a threshold value, the input side of the dc/dc power converter 10 is determined to be powered off.
Referring to fig. 3, specifically, the electronic switch Qx includes a first terminal, a second terminal and a control terminal, the first terminal is connected to the first resistor Ra, the second terminal is connected to the ground terminal 12, the control terminal is connected to the controller 40, for example, a transistor (e.g., a MOSFET), the first terminal is a Drain terminal (Drain), the second terminal is a Source terminal (Source), and the control terminal is a Gate terminal (Gate); alternatively, the electronic switch Qx may be a diode, and the anode terminal and the cathode terminal thereof are connected to the first resistor Ra and the ground terminal 12, respectively. The bypass device 21 can be a transistor (e.g., MOSFET), and for example, as shown in fig. 3, the bypass device 21 is a transistor Qy and includes a first terminal, a second terminal and a control terminal, wherein the first terminal is connected to the series node n, the second terminal is connected to the ground terminal 12, the control terminal is connected to the controller 40, for example, the first terminal can be a Drain terminal (Drain), the second terminal can be a Source terminal (Source), and the control terminal can be a Gate terminal (Gate); alternatively, the bypass device 21 can be a diode, and the anode terminal and the cathode terminal thereof are connected to the ground terminal 12 and the series node n, respectively. Therefore, the controller 40 can control whether the electronic switch Qx, the transistor Qy and the switch Qz are turned on or off.
It should be noted that, since the second capacitor Cb is directly connected to the power source terminal 11 and the ground terminal 12 of the dc/dc power converter 10, the second capacitor Cb is always in an on-line state, and thus must bear the voltage fluctuation range of the input side of the dc/dc power converter 10, and on the contrary, the first capacitor Ca is not always in an on-line state as an auxiliary capacitor for prolonging the holding time, so the withstand voltage of the first capacitor Ca can be smaller than that of the second capacitor Cb, and the withstand voltage of the present invention can be the peak voltage that each capacitor can bear.
The circuit operation of the embodiment of fig. 3 will be described below with reference to the timing chart shown in fig. 4. On the other hand, please refer to fig. 6 for another possible embodiment of the bypass device 21, which can be directly connected in parallel to the first resistor Ra, and the timing diagram of this embodiment can also refer to fig. 4.
Period S1: an input voltage V at the input side of the reverse-flow prevention protection circuit 50INWhen the switch Qz and the transistor Qy are open, the electronic switch Qx is turned on. At this time, a first capacitor Ca is connected in series with a first resistor Ra and then connected in parallel with a second capacitor Cb, the first capacitor Ca and the second capacitor Cb are charged simultaneously, and a terminal voltage V of the first capacitor CaCaTerminal voltage V to the second capacitor CbCbWhile incrementing.
Period S2: when the controller 40 determines the terminal voltage V of the first capacitor CaCaReaches an upper limit value VOFF,QxAnd when the input side of the dc/dc power converter 10 is not powered off, the controller 40 controls the electronic switch Qx to be open and stops charging the first capacitor Ca, wherein the first capacitor Ca is slowly discharged due to the small leakage current generated by the capacitance dielectric material, so that the terminal voltage V thereofCaThere is a decreasing trend. On the other hand, when the first capacitor Ca reaches the upper limit value VOFF,QxAt this time, since the withstand voltage of the first capacitor Ca is smaller than that of the second capacitor Cb, the second capacitor Cb has not yet reached the upper limit value of the second capacitor Cb itself, and the second capacitor Cb is continuously charged through the second resistor Rb.
Period S3: when the controller 40 determines the terminal voltage V of the second capacitor CbCbWhen a stable value is reached, the switch Qz is turned on to pass a current through the switch Qz without passing through the second resistor Rb, thereby reducing circuit loss.
Period S4: with the terminal voltage V of the first capacitor CaCaDecreasing when the controller 40 determines the terminal voltage V of the first capacitor CaCaReaches a lower limit value VON,QxAt this time, the controller 40 turns on the electronic switch Qx, so that the first capacitor Ca is charged through the first resistor Ra. Then, when the first capacitor Ca is charged, its terminal voltage VCaRises to the upper limit value VOFF,QxAt this time, the controller 40 controls the electronic switch Qx to be open to stop charging the first capacitor Ca. Therefore, the first capacitor Ca is repeatedCharging and discharging to maintain a stable voltage range (i.e., between the upper limit value V)OFF,QxWith a lower limit value VON,QxInterval (c) of the light source.
Period S5: the input voltage V of the power supply is after the AC power supply is cut offINWhen the power is cut off, the second capacitor Cb begins to discharge, so its terminal voltage VCbThe input side of the DC/DC power converter 10 is mainly powered by the second capacitor Cb to make the DC power VOUTAnd continuously maintaining the stability.
Period S6: when the controller 40 determines the terminal voltage V of the second capacitor CbCbWhen the voltage of the first capacitor Ca is lower than the threshold value, the controller 40 turns on the electronic switch Qx, and the first capacitor Ca and the second capacitor Cb perform a voltage balancing mechanism through the first resistor Ra to balance the voltage V of the first capacitor CaCaTerminal voltage V to the second capacitor CbCbApproaching each other. In this embodiment, as shown in fig. 4, when the electronic switch Qx is turned on, the terminal voltage V of the second capacitor Cb is lowerCbLower than the terminal voltage V of the first capacitor CaCaTherefore, the second capacitor Cb is influenced by the first capacitor Ca to make its terminal voltage VCbSlightly rising.
Period S7: when the controller 40 determines the voltage V between the two terminalsCa、VCbWhen the difference is equal to or less than a tolerance, the controller 40 can turn on the transistor Qy, and the electronic switch Qx and the transistor Qy are turned on simultaneously, please refer to fig. 5, the first capacitor Ca provides a first discharging path Pa, the second capacitor Cb provides a second discharging path Pb, the two discharging paths Pa, Pb converge and enter the input side of the dc/dc power converter 10, so that the first capacitor Ca and the second capacitor Cb provide energy to the dc/dc power converter 10 at the same time. It should be noted that, in the present invention, the transistor Qy is not turned on in the time period S6, but the first capacitor Ca and the second capacitor Cb are in voltage balance before the transistor Qy is turned on in the time period S7, so that the transistor Qy is turned on when the first capacitor Ca and the second capacitor Cb are in voltage balance, and the transient turning-on of the transistor Qy can be effectively avoidedAnd extremely large currents are generated.
In summary, after the ac power is turned off, the first capacitor Ca and the second capacitor Cb discharge together to the input side of the dc/dc power converter 10, so that the output side of the dc/dc power converter 10 can maintain the dc power VOUTAnd then decremented over time, or at a slower rate. For the load 60, the hold-up time is relatively extended to perform the emergency procedure after power-off. Furthermore, when the power supply is operating normally, the second capacitor Cb must be able to withstand the voltage fluctuation range of the input side of the dc/dc power converter 10, and the electronic switch Qx and the transistor Qy are in the open circuit state, so the first capacitor Ca does not need to be considered to withstand the voltage fluctuation, and the capacitance and voltage withstanding characteristics of the first capacitor Ca can be smaller than those of the second capacitor Cb; in other words, compared with a large-capacity capacitor, the first capacitor Ca of the present invention has a lower capacity, so that the present invention can be implemented at a lower cost and has a smaller volume, and the design of the whole mechanism of the system is not inconvenient.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it should be understood that various changes and modifications can be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (7)
1. A power supply capable of extending a retention time after power-off, comprising:
a DC/DC power converter including an input side and an output side;
a hold-up time control circuit connected to the input side of the DC/DC power converter, comprising:
a first capacitor connected to the input side of the DC/DC power converter;
a first resistor connected in series with the first capacitor; and
an electronic switch connected in series with the first capacitor and the first resistor;
a second capacitor connected in parallel to the holding time control circuit, wherein the withstand voltage of the first capacitor is smaller than that of the second capacitor, and the withstand voltage is the peak voltage that the capacitor can bear; and
a controller, connecting the hold-up time control circuit and the second capacitor, when the controller determines that the input side of the DC/DC power converter is not powered off, the controller controls the electronic switch to be open-circuit, when the controller determines that the input side of the DC/DC power converter is powered off, the controller switches on the electronic switch, and the first capacitor and the second capacitor discharge to the input side of the DC/DC power converter together;
when the input side of the DC/DC power converter is not powered off, when the controller judges that the terminal voltage of the first capacitor reaches an upper limit value, the electronic switch is controlled to be open-circuit to stop charging the first capacitor; when the controller judges that the terminal voltage of the first capacitor reaches a lower limit value, the electronic switch is conducted to charge the first capacitor.
2. The power supply of claim 1 further comprising an inrush current suppression circuit;
the input side of the DC/DC power converter is provided with a power supply end and a grounding end;
the surge current suppression circuit comprises a second capacitor, a second resistor and a change-over switch, wherein two ends of the second capacitor are respectively connected with a power supply end and a grounding end of the DC/DC power supply converter, the change-over switch is connected with the grounding end, and the second resistor is connected in parallel with the change-over switch;
the controller is connected with a control end of the change-over switch.
3. The power supply of claim 2, wherein the hold time control circuit comprises a bypass element connected between a serial node of the first capacitor and the first resistor and the ground terminal.
4. The power supply of claim 3, wherein the bypass device is a transistor and comprises a first terminal, a second terminal and a control terminal, the first terminal is connected to the series node, the second terminal is connected to the ground terminal, and the control terminal is connected to the controller.
5. The power supply of claim 2, wherein the hold-up time control circuit comprises a bypass device directly connected in parallel to the first resistor.
6. The power supply as claimed in any one of claims 1 to 3 and 5, wherein when the controller determines that the voltage across the second capacitor is lower than a threshold value when the input side of the DC/DC power converter is powered off, the controller turns on the electronic switch to balance the voltages of the first capacitor and the second capacitor through the first resistor.
7. The power supply as claimed in claim 4 or 5, wherein when the input side of the dc/dc power converter is powered off, and the controller determines that the terminal voltage of the second capacitor is lower than a threshold value, the controller turns on the electronic switch to open the bypass device, so that the first capacitor and the second capacitor perform a voltage balancing mechanism through the first resistor;
when the controller judges that the terminal voltages of the first capacitor and the second capacitor are equal or the error is lower than an allowable value, the controller simultaneously conducts the bypass element and the electronic switch.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710514503.4A CN109217655B (en) | 2017-06-29 | 2017-06-29 | Power supply capable of prolonging maintenance time after power failure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710514503.4A CN109217655B (en) | 2017-06-29 | 2017-06-29 | Power supply capable of prolonging maintenance time after power failure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109217655A CN109217655A (en) | 2019-01-15 |
| CN109217655B true CN109217655B (en) | 2021-01-01 |
Family
ID=64976643
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710514503.4A Active CN109217655B (en) | 2017-06-29 | 2017-06-29 | Power supply capable of prolonging maintenance time after power failure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109217655B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112909885B (en) * | 2021-03-03 | 2023-01-24 | 日立楼宇技术（广州）有限公司 | Control method and device of variable frequency control circuit, computer equipment and storage medium |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203457044U (en) * | 2013-09-27 | 2014-02-26 | 南京国睿新能电子有限公司 | Ultra long time power failure holding circuit |
-
2017
- 2017-06-29 CN CN201710514503.4A patent/CN109217655B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109217655A (en) | 2019-01-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9667094B1 (en) | Battery backup system for uninterrupted power supply | |
| US7042197B2 (en) | Control circuit | |
| US7474079B2 (en) | Battery charger with backup charging circuit | |
| KR101102731B1 (en) | Battery charging and discharging apparatus and method | |
| US7852059B2 (en) | Power supply device | |
| JPH0870575A (en) | Circuit and method for stabilizing ac line for high-power-factor load | |
| US20230341459A1 (en) | Power-loss delay circuit and detection control circuit thereof | |
| US6949912B2 (en) | Enabling circuit for avoiding negative voltage transients | |
| CN113271001A (en) | Power management chip, switching power management system and method | |
| CN109217655B (en) | Power supply capable of prolonging maintenance time after power failure | |
| TWM552706U (en) | Power supply to extend the sustaining time after service interruption | |
| US10819143B1 (en) | Redundant power supply device and redundant power supply device protection control method | |
| JP2001211562A (en) | Charging circuit having plurality of modes | |
| CN109888763B (en) | Disconnection detection and protection method for power module redundancy energy-taking circuit | |
| CN104426127A (en) | Load starting circuit | |
| JP2009095107A (en) | Uninterruptible backup power supply device | |
| TW201308811A (en) | Standby battery protection system | |
| CN113659819B (en) | Power-down delay control method and control circuit | |
| JP2008035573A (en) | Electricity accumulation device employing electric double layer capacitor | |
| JP3457364B2 (en) | Power supply with backup function | |
| TWI655827B (en) | Uninterruptible power supply | |
| CN109217450B (en) | Redundant power supply system capable of prolonging maintenance time after power failure | |
| JP2009171724A (en) | Bidirectional converter | |
| JP2003079058A (en) | Battery pack | |
| US11545891B2 (en) | Power device and operation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |