SUMMERY OF THE UTILITY MODEL
To the above-mentioned technical problem that prior art exists, the utility model provides a charging circuit, include:
a first rectifying circuit;
a power factor correction circuit, the input end of which is connected to the output end of the first rectifying circuit;
a power factor correction controller for controlling an operating state of the power factor correction circuit;
the input end of the charger is electrically connected to the output end of the power factor correction circuit;
a charging controller for controlling an operating state of the charger;
a switch connected between an input terminal of the first rectifying circuit and an alternating current power supply;
the input end of the second rectifying circuit is connected to the alternating current power supply, and the output end of the second rectifying circuit is connected to the input end of the charger; and
a control device, a power input terminal of which is connected to the output terminal of the charger, configured to control the switch to be turned off and control the power factor correction controller to make the power factor correction circuit not work when the voltage of the alternating current power supply is not in the input voltage range allowed by the charging circuit.
Preferably, the charging circuit further includes a start-up energy storage circuit including a first input terminal connected to the positive output terminal of the second rectifying circuit, a second input terminal connected to the output terminal of the charger, and an output terminal, the start-up energy storage circuit is configured to output a dc supply voltage according to the dc power output by the second rectifying circuit or the dc power output by the charger, and the output terminal of the start-up energy storage circuit is connected to the power input terminal of the charging controller.
Preferably, the charging circuit further comprises an overvoltage protection circuit, a power supply input terminal of which is connected to the output terminal of the starting energy storage circuit, and the overvoltage protection circuit is configured to control the charger not to work when the voltage of the alternating current power supply exceeds the maximum value in the input voltage range allowed by the charging circuit.
Preferably, a power supply input terminal of the pfc controller is connected to a positive output terminal of the charger.
Preferably, the second rectification circuit includes: a first diode having an anode connected to a power supply terminal of the alternating current power supply and a cathode connected to a positive input terminal of the charger; and a first capacitor connected between the positive input terminal and the negative input terminal of the charger.
Preferably, the charging circuit further comprises a second diode, an anode of which is connected to the anode output terminal of the power factor correction circuit, and a cathode of which is connected to the anode input terminal of the charger.
Preferably, the starting energy storage circuit comprises a first resistor and a second capacitor, a node formed by connecting one end of the first resistor and one end of the second capacitor is used as an output end of the starting energy storage circuit, the other end of the first resistor is connected to a positive output terminal of the second rectifying circuit, and the other end of the second capacitor is connected to a negative output terminal of the charger.
Preferably, the start-up energy storage circuit further comprises a third diode, an anode of the third diode is connected to the anode output terminal of the charger, and a cathode of the third diode is connected to the node.
Preferably, the control device comprises a switching power supply and a digital signal processor, a power supply input terminal of the switching power supply is connected to the positive output terminal of the charger and is used for supplying required direct current to the digital signal processor, and the digital signal processor is used for controlling the switching state of the switch and controlling the working state of the power factor correction controller.
Preferably, the first rectifying circuit is a full-wave rectifying circuit.
Preferably, the power factor correction circuit is a boost chopper circuit.
Preferably, the charger is a flyback charger.
The utility model provides an uninterrupted power supply, it includes as above charging circuit.
The utility model discloses a charging circuit can realize overvoltage protection, avoids power factor correction circuit to receive voltage shock and damages.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clearly apparent, the present invention is further described in detail by the following embodiments with reference to the accompanying drawings.
Fig. 2 is a block diagram of a charging circuit according to a preferred embodiment of the present invention. As shown in fig. 2, the charging circuit 2 includes a first rectifyingcircuit 21, a powerfactor correction circuit 22, acharger 23, a powerfactor correction controller 25 for controlling the operating state of the powerfactor correction circuit 22, acharging controller 24 for controlling the operating state of thecharger 23, a switch S2, a second rectifyingcircuit 20, astartup tank circuit 27, anovervoltage protection circuit 29, aswitching power supply 28, and adigital signal processor 26.
The switch S2 is connected between the input terminal of thefirst rectifier circuit 21 and the power supply terminal of the ac power supply. An input terminal of the powerfactor correction circuit 22 is connected to an output terminal of the first rectifyingcircuit 21, an input terminal of thecharger 23 is electrically connected to an output terminal of the powerfactor correction circuit 22, an input terminal of the second rectifyingcircuit 20 is connected to a power supply terminal of the alternating current power supply, and an output terminal thereof is connected to an input terminal of thecharger 23. The anode of the diode D22 is connected to the anode output terminal of the powerfactor correction circuit 22, and the cathode thereof is connected to theanode input terminal 231 of thecharger 23. The first input 271 of the start-up tank circuit 27 is connected to thepositive input terminal 231 of the charger 23 (i.e. the positive output terminal of the second rectifying circuit 20), and thesecond input 272 thereof is connected to the output of thecharger 23, and the start-up tank circuit 27 is configured to output the required dc supply voltage by using the dc power output from the second rectifyingcircuit 20 or the dc power output from thecharger 23.
The output of thestartup tank circuit 27 is connected to the supply input terminals of thecharge controller 24 and theovervoltage protection circuit 29 for supplying the required dc power to thecharge controller 24 and theovervoltage protection circuit 29. The positive output terminal of thecharger 23 is connected to the power supply input terminals of the powerfactor correction controller 25 and theswitching power supply 28 for supplying the required direct current to the powerfactor correction controller 25 and theswitching power supply 28.
Theswitching power supply 28 is used to supply the required dc power to thedigital signal processor 26, and thedigital signal processor 26 is configured to monitor the voltage Vi of the ac power supply, and when the voltage Vi of the ac power supply is not in the voltage range allowed by the charging circuit 2, the switch S2 is controlled to be turned off, and thepfc controller 25 is controlled not to operate. Theovervoltage protection circuit 29 is configured to control thecharger 23 to stop operating when the voltage Vi of the alternating-current power supply exceeds the maximum value of the voltage range allowed by the charging circuit 2.
Thecharger controller 24, theovervoltage protection circuit 29, the powerfactor correction controller 25, theswitching power supply 28, thedigital signal processor 26 and the like in the present invention can be realized by using a chip or a circuit module in the prior art, and the specific circuit structure thereof will not be described in detail herein.
When the charging circuit 2 is started, the second rectifyingcircuit 20 rectifies the alternating current of the alternating current power supply into direct current and transmits the direct current to the input end of thecharger 23, and the startingenergy storage circuit 27 outputs required direct current voltage by using the direct current output by the second rectifyingcircuit 20 and provides the required direct current voltage for thecharging controller 24. Thecharge controller 24 controls the operation of thecharger 23. Thecharger 23 thus starts and outputs a direct current, and supplies power to the powerfactor correction controller 25 and theswitching power supply 28. Theswitching power supply 28 supplies thedigital signal processor 26 with the required dc power, e.g., 5 volts, 12 volts, etc., so that thedigital signal processor 26 starts operating. Thedigital signal processor 26 monitors the voltage Vi and determines whether the voltage Vi is within an input voltage range allowed by the charging circuit 2, for example, between 110 volts and 300 volts. The operating principle of the charging circuit 2 will be described below separately in different voltage ranges according to the voltage Vi of the ac power supply.
(11) When the voltage Vi is within the input voltage range allowed by the charging circuit 2, thedigital signal processor 26 controls the switch S2 to be closed. The first rectifyingcircuit 21 rectifies alternating current supplied from an alternating current power supply into direct current. Thepfc controller 25 controls thepfc circuit 22 to operate and transmit it to the input terminal of thecharger 23 through the diode D22. Thecharging controller 24 controls thecharger 23 to operate, and thecharger 23 outputs direct current to charge a rechargeable battery (not shown in fig. 2). The start-up tank circuit 27 outputs a dc voltage using the dc output from thecharger 23 to power thecharge controller 24 and theovervoltage protection circuit 29. Whereby the charging circuit 2 starts to operate normally.
(12) During the charging process, when the voltage Vi of the ac power supply increases, for example, greater than the maximum value of the allowable input voltage range (for example, 300 volts), thedigital signal processor 26 controls the switch S2 to be turned off, and controls thepfc controller 25 to be inactive. The switch S2, which is open at this time, isolates the ac power from the input terminal of the powerfactor correction circuit 22, and the diode D22 is in a reverse cut-off state for isolating the output terminal of thesecond rectifying circuit 20 from both the output terminals of the powerfactor correction circuit 22. Even if the voltage Vi increases, the electronic components in the powerfactor correction circuit 22 are not damaged. Meanwhile, when theovervoltage protection circuit 24 monitors that the voltage Vi of the alternating current power supply is larger than the maximum value of the allowable input voltage range, thecharger 23 is controlled to stop working, and therefore electronic components in thecharger 23 are protected.
(2) When the voltage Vi is not within the input voltage range allowed by the charging circuit 2, for example, less than 110 volts or greater than 300 volts, thedigital signal processor 26 controls the switch S2 to be turned off, and controls thepfc controller 25 to be inactive.
The input terminal of thesecond rectifying circuit 20 is connected to the power supply terminal of the ac power supply, and when the switch S2 is in the off state, thesecond rectifying circuit 20 can also rectify the ac power into the dc power and output the dc power to the first input terminal 271 of the startenergy storage circuit 27, the dc power output by the startenergy storage circuit 27 is transmitted to the chargingcontroller 24, and the chargingcontroller 24 thereby controls thecharger 23 to start operating.
The anode of the diode D22 is connected to the anode output terminal of the powerfactor correction circuit 22, and the cathode is connected to the anode output terminal of thesecond rectification circuit 20, so that the diode D22 is turned off in the reverse direction during the startup of the charging circuit 2, and the dc voltage output by thesecond rectification circuit 20 is not applied to the powerfactor correction circuit 22, thereby effectively protecting the electronic components in the powerfactor correction circuit 22.
When the voltage Vi of the ac power supply sharply increases, the switch S2 is controlled to be turned off, and the ac power cannot be transmitted to the input terminal of the powerfactor correction circuit 22 through thefirst rectification circuit 21, thereby protecting the powerfactor correction circuit 22.
When the voltage Vi monitored by theovervoltage protection circuit 29 exceeds the maximum value in the allowable power supply voltage range, thecharger 23 is controlled to stop working, so that thesecond rectification circuit 20 is prevented from outputting a higher direct-current voltage to damage electronic components in thecharger 23.
Therefore the utility model discloses a charging circuit 2 has realized the overvoltage protection function to powerfactor correction circuit 22 andcharger 23, damages charging circuit 2 when avoiding alternating current power supply's voltage Vi to increase to the great value.
Fig. 3 is a specific circuit configuration diagram of the charging circuit shown in fig. 2. As shown in fig. 3, the first rectifying circuit 21 'in the charging circuit 2' includes a full-wave rectifying circuit formed by connecting four diodes, and the specific connection manner is well known to those skilled in the art and will not be described herein again. The power factor correction circuit 22' includes a boost chopper circuit formed by connecting an inductor, a diode, a switching transistor and a capacitor, and the operation principle and the specific connection mode thereof are well known to those skilled in the art and will not be described herein. The charger 23' includes a flyback charger formed by connecting a transformer, a switching transistor, a diode and a capacitor, and the operation principle and the specific connection mode thereof are well known to those skilled in the art and will not be described herein.
The switch S2 'is connected between thepower supply terminal 201 of the ac power supply and one input terminal of the first rectification circuit 21'.
The second rectifier circuit 20' includes a half-wave rectifier circuit formed by connecting a diode D21 and a capacitor C21. Wherein the anode of the diode D21 is connected to thepower supply terminal 201 of the ac power supply, the cathode thereof is connected to one end of the capacitor C21, and the two ends of the capacitor C21 are used as the anode output terminal and the cathode output terminal of the second rectifying circuit 20 ', which are respectively connected to the anode input terminal and the cathode input terminal of the charger 23'.
The start-up energy storage circuit 27 'includes a diode D27, a resistor R27 and a capacitor C27, a node N27 formed by connecting one end of the resistor R27, a cathode of the diode D27 and one end of the capacitor C27 serves as an output end of the start-up energy storage circuit 27', the other end of the resistor R27 serves as a first input end connected to the anode input terminal 231 '(i.e., the anode output terminal of the first rectifying circuit 20') of the charger 23 ', and the anode of the diode D27 and the other end of the capacitor C27 serve as second input ends connected to the anode and cathode output terminals of the charger 23', respectively.
The start-up process of the charging circuit 2 'will be described in detail below with reference to a specific circuit configuration diagram of the charging circuit 2' shown in fig. 3.
The conductive path formed by the ac power source through the second rectifier circuit 20' is as follows: thesupply terminal 201 of the alternating current power supply, the diode D21, the capacitor C21, the diode D2 in the first rectifying circuit 21' to thesupply terminal 202 of the alternating current power supply. Whereby the alternating current in the alternating current power supply is stored in the capacitor C21. The capacitor C21 charges the capacitor C27 through the resistor R27, thereby obtaining a stepped-down dc current at the capacitor C27. The power of the capacitor C27 powers the charge controller 24 ', and the charge controller 24 ' starts to control the charger 23 ' to output dc power. A portion of the dc power output from the charger 23 ' powers the pfc controller 25 ' and the switching power supply 28 ', and another portion is stored in the capacitor C27 through the diode D27 to power the charging controller 24 ' and the overvoltage protection circuit 29 '. The switching power supply 28 ' supplies the required dc power to the digital signal processor 26 ' and the digital signal processor 26 ' begins to operate. The digital signal processor 26 'monitors the voltage Vi and determines whether the voltage Vi is within the input voltage range allowed by the charging circuit 2'.
When the voltage Vi is within the input voltage range allowed by the charging circuit 2 ', the digital signal processor 26 ' controls the switch S2 ' to be closed. The first rectifying circuit 21' rectifies alternating current supplied from an alternating current power supply into direct current. The power factor correction controller 25 'controls the power factor correction circuit 22' to operate, and the power factor correction circuit 22 'outputs the direct current with the boosted voltage and stores the electric energy to thecapacitor 21 through the diode D22'. The charging controller 24 ' controls the charger 23 ' to operate, whereby the charger 23 ' outputs a desired direct current. The dc power output from the charger 23 ' charges the capacitor C27 through the diode D27, and the electric energy stored in the capacitor C27 is used to power the charge controller 24 ' and the overvoltage protection circuit 29 '.
During the charging process, when the voltage Vi of the ac power increases so as to exceed the maximum value in the input voltage range allowed by the charging circuit 2 ', the digital signal processor 26 ' controls the switch S2 ' to be turned off so as to protect the power factor correction circuit 22 ', and controls the power factor correction controller 25 ' to be inoperative. Meanwhile, when the overvoltage protection circuit 24 ' monitors that the voltage Vi of the alternating current power supply is greater than the maximum value in the allowable input voltage range, the charger 23 ' is controlled not to work, so that electronic components in the charger 23 ' are protected.
The resistor R27 in the start-up tank circuit 27 ' is used to divide the voltage so that the capacitor C27 has the proper voltage across it to supply to the charge controller 24 ' to control the start-up of the charger 23 '. During the start-up of the charger 27 ', the diode D27 is turned off in the reverse direction, and the dc power of the capacitor C27 only powers the charge controller 24' and the overvoltage protection circuit 29 ', so as to ensure that the charger 23' is provided with enough dc power to start up normally. And when the charger 23 'charges the rechargeable battery, the dc power at the output terminal of the charger 23' is stored in the capacitor C27 through the diode D27, and the capacitor C27 is used to provide stable dc power to the charge controller 24 'and the overvoltage protection circuit 29'.
The second rectifying circuit 20 'in the above embodiment multiplexes the diode D2 in the first rectifying circuit 21' during the starting process, thereby saving components and reducing the cost.
The utility model discloses a components and parts in the chopper circuit 22' that steps up are small in quantity, and are with low costs. In other embodiments of the present invention, other power factor correction circuits may be used instead of the boost chopper circuit 22'.
The flyback charger 23' has a small number of components and is low in cost. In other embodiments of the present invention, other chargers capable of converting the dc power into the dc power for voltage reduction may be used to replace the flyback charger 23'.
In other embodiments of the present invention, other rectification circuits may be used to replace the full-wave rectification circuit 21'.
In another embodiment of the present invention, the charging circuit 2 'further includes a thermistor connected between thepower supply terminal 201 of the ac power source and one input terminal of the first rectifying circuit 21' for reducing the surge voltage of the ac power.
In another embodiment of the present invention, the diode D27 in the start-up tank circuit 27' may be removed.
In yet another embodiment of the present invention, the charging circuit 2 'does not include the diode D22'.
In another embodiment of the present invention, a control device with a voltage comparison function may be used to replace the digital signal processor 26 ' and the switching power supply 28 ' in the above embodiment, wherein the power input terminal of the control device is connected to the output terminal of the charger 23 ' and is configured to compare the voltage Vi of the ac power supply with the allowable input voltage range, thereby controlling the switching state of the switch S2 ' and controlling the operating state of the pfc controller 25 '. When the voltage Vi is not in the input voltage range allowed by the charging circuit 2 ', the control switch S2 ' is turned off, and the power factor correction controller 25 ' is controlled not to operate.
Although the present invention has been described in connection with the preferred embodiments, it is not intended to limit the invention to the embodiments described herein, but rather, to include various changes and modifications without departing from the scope of the invention.