CN216699856U - Constant power supply with adjustable output voltage - Google Patents
Constant power supply with adjustable output voltage Download PDFInfo
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- CN216699856U CN216699856U CN202123452080.9U CN202123452080U CN216699856U CN 216699856 U CN216699856 U CN 216699856U CN 202123452080 U CN202123452080 U CN 202123452080U CN 216699856 U CN216699856 U CN 216699856U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
The utility model provides a constant power supply with adjustable output voltage, which comprises a mains supply input line, a switching transformer conversion circuit, a controller U1 and an adjusting feedback circuit which are electrically connected with each other, wherein the output voltage is adjusted by controlling a potentiometer R14. The utility model can realize fine adjustment in the voltage range of 3.3-20V, and the constant power supply has high precision and high stability, and is beneficial to protecting the use of the voltage stabilizer.
Description
Technical Field
The utility model relates to the technical field of constant power supplies, in particular to a constant power supply with adjustable output voltage.
Background
The main function of the conventional adjustable dc voltage-stabilized source is to convert ac mains supply into dc power (mostly, low-voltage dc power is used), and provide a dc voltage source with constant voltage, and the output voltage can be adjusted and set as required within the product design range.
The direct current stabilized voltage supply is mainly used as a working power supply of electronic components, a low-voltage lamp, a direct current motor and a fixed power supply for product life tests in research units and laboratories or on production lines, is the best choice, has a perfect protection circuit and can meet the simple and convenient use requirements of users.
Compared with the traditional power supply, the adjustable power supply can provide any voltage output within the design range, can replace the power supply adapter and the power supply circuit used by a plurality of electronic products,
many modern electronic products, especially consumer electronic products for civil use, including mobile phones, notebook computers and digital products, are driven by low-voltage direct current, and many faults are caused by faults of power adapters or power units, so that the electronic products are widely used in product development and maintenance.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a constant power supply with adjustable output voltage, which can be finely adjusted in a voltage range of 3.3-20V, has high precision and high stability and is beneficial to protecting the use of a voltage stabilizer.
To this end, a constant power supply with adjustable output voltage is provided, comprising:
the system comprises a mains supply input line, a power supply output line and a power supply output line, wherein the mains supply input line comprises a positive bus and a negative bus, and the positive bus and the negative bus respectively take power from mains supply;
the switching transformer conversion circuit comprises a transformer T1 and a switching tube Q1, wherein the switching tube Q1 is connected with the output end of the lightning protection circuit to obtain electricity, alternating-current voltage of commercial power is converted into direct-current voltage and then input to one end of the primary side of the transformer T1, the other end of the primary side of the transformer T1 is connected to the controller U1 through a switching tube Q1, the secondary side of the transformer T1 is connected with external electric equipment to supply power, and an auxiliary winding on the secondary side of the transformer T1 is connected with a VCC end of the controller U1; the adjusting feedback circuit comprises an optocoupler U2 and a potentiometer R14, the output end of a transformer T1 is divided into two branches, one end of the secondary side of the transformer T1 is respectively connected with the ground after passing through a series resistor R9, a resistor R13 and a controllable precise voltage-stabilizing source U3, the other branch is connected with the ground after passing through a resistor R10, a resistor R15 and a resistor R22, and the other branch is connected with the groundThe emitting end of the optocoupler U2 is connected in parallel with two ends of a resistor R13, the potentiometer R14 is connected in parallel with two ends of a resistor R15, and a node between the resistor R22 and the resistor R15 is connected with a U of a controllable precise voltage-stabilizing source U3REFAnd at the end, an optical coupler U2 and a potentiometer R14 are respectively and electrically connected with the controller U1.
Further, the resistor R13 and the U of the controllable precise voltage-stabilizing source U3REFA capacitor C7 and a resistor R16 are connected in series between the ends.
Furthermore, the power supply system also comprises an EMI rectification circuit which is divided into two paths after the mains supply is taken from the mains supply input line, wherein one path of the voltage is rectified by a rectifier bridge stack BD1 and then output to an electrolytic capacitor C1 to be filtered into smooth direct-current voltage, the direct-current voltage is transmitted to a switching transformer conversion circuit, the other path of the voltage is used for collecting input voltage through a node between a diode D2 and a diode D3 which are sequentially connected in series, the conduction direction of the diode D2 points to a negative bus, and the conduction direction of the diode D3 points to a positive bus.
Further, the power supply device further comprises a secondary side rectification filtering output circuit, wherein the output end of the transformer T1 is connected with external electric equipment for power supply after sequentially passing through a Schottky diode D1, a capacitor C5, a capacitor C6 and a common mode inductor LF 2.
Furthermore, the device also comprises an absorption resistor formed by connecting a resistor R5 and a resistor R5A in parallel, wherein one end of the absorption resistor is connected with the input end of the Schottky diode D1, and the other end of the absorption resistor is connected with the output end of the Schottky diode D1 through a capacitor C3.
And further, the lightning protection circuit comprises a voltage dependent resistor MOV1 connected between the positive bus and the negative bus in parallel and a voltage dependent resistor NTC1 electrically connected with the negative bus, and the mains supply sequentially flows through the voltage dependent resistor MOV1 and the voltage dependent resistor NTC1 and then is output to the EMI rectification circuit.
The constant power supply with adjustable output voltage is provided with a mains supply input circuit, a lightning protection circuit, a switching transformer conversion circuit, an adjusting feedback circuit and a controller U1 which are electrically connected with each other, the output voltage is adjusted through an adjusting potentiometer R14, fine adjustment can be achieved within the voltage range of 3.3-20V, and the constant power supply has high precision and high stability and is beneficial to protecting the use of a voltage stabilizer.
The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.
Drawings
Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the utility model. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:
fig. 1 is a schematic diagram of a connection structure of a constant power supply with adjustable output voltage according to the present invention.
Reference numerals: 1-mains supply input line; 2-lightning protection circuit; 3-an EMI rectification circuit; 4-a switching transformer conversion circuit; 5-secondary side rectification filter output circuit; 6-adjusting the feedback circuit; 7-PWM pulse circuit.
Detailed Description
The utility model is further described with reference to the following examples.
In the embodiment, a mains supply input line 1 is connected with an EMI (electro-magnetic interference) rectification filter circuit through a lightning protection circuit 2, one path of the EMI rectification filter circuit is connected with a switching transformer conversion circuit 4, and the other path of the EMI rectification filter circuit is connected with a PWM (pulse-width modulation) pulse circuit 7; one path of the switch transformer converter is connected with the PWM pulse circuit 7, and the other path of the switch transformer converter is connected with the secondary rectification output circuit to transmit output voltage; the secondary side rectification output circuit is connected with the regulation feedback circuit 6 to collect residual voltage, outputs the output voltage and the residual voltage to external power supply equipment, and ensures stable power supply of the power supply equipment through the residual voltage.
Referring to fig. 1, the constant power supply with adjustable output voltage of the present embodiment includes a mains input line, which includes a positive bus and a negative bus, where the positive bus and the negative bus respectively take power from the mains; switch transformerThe conversion circuit comprises a transformer T1 and a switching tube Q1, wherein the switching tube Q1 is connected with the output end of the lightning protection circuit to obtain electricity, alternating-current voltage of commercial power is converted into direct-current voltage and then input to one end of the primary side of the transformer T1, the other end of the primary side of the transformer T1 is connected to the controller U1 through a switching tube Q1, the secondary side of the transformer T1 is connected with external electric equipment to supply power, and an auxiliary winding on the secondary side of the transformer T1 is connected with a VCC end of the controller U1; the adjusting feedback circuit comprises an optocoupler U2 and a potentiometer R14, the output end of a transformer T1 is divided into two branches, one end of the secondary side of the transformer T1 is connected with the ground after passing through a series resistor R9, a resistor R13 and a controllable precise voltage-stabilizing source U3 respectively, the other branch is connected with the ground after passing through a resistor R10, a resistor R15 and a resistor R22, the transmitting end of the optocoupler U2 is connected with two ends of a resistor R13 in parallel, the potentiometer R14 is connected with two ends of a resistor R15 in parallel, and a node between the resistor R22 and the resistor R15 is connected with a U3 of the controllable precise voltage-stabilizing source U3REFAnd the optical coupler U2 and the potentiometer R14 are electrically connected with the controller U1 respectively. The output voltage is adjusted by adjusting the potentiometer R14, fine adjustment can be achieved within the voltage range of 3.3-20V, and the constant-power supply has high precision and high stability and is beneficial to protecting the use of a voltage stabilizer.
Further, an optocoupler U2 is connected between the D pole of the NPN triode Q2 and the output end of the transformer T1, a resistor R22 is connected between the S pole of the NPN triode Q2 and the S pole of the NPN triode Q3, and the series resistor R10 and the resistor R15 are connected with the output end of the transformer T1 through a voltage regulator tube D8.
Further, the power supply system also comprises an EMI rectification circuit 3 which is divided into two paths after the commercial power is taken from the commercial power supply line, wherein one path is rectified by a rectifier bridge stack BD1 and then output to an electrolytic capacitor C1 to be filtered into smooth direct-current voltage, the direct-current voltage is transmitted to a switching transformer conversion circuit 4, the other path is connected with a node between a diode D2 and a diode D3 in series in sequence to collect input voltage, the conduction direction of the diode D2 points to a negative bus, and the conduction direction of the diode D3 points to a positive bus.
Further, the power supply device further comprises a secondary side rectification filtering output circuit 5, wherein the output end of the transformer T1 is connected with external electric equipment for power supply after sequentially passing through a Schottky diode D1, a capacitor C5, a capacitor C6 and a common mode inductor LF 2.
Furthermore, the device also comprises an absorption resistor formed by connecting a resistor R5 and a resistor R5A in parallel, wherein one end of the absorption resistor is connected with the input end of the Schottky diode D1, and the other end of the absorption resistor is connected with the output end of the Schottky diode D1 through a capacitor C3.
Further, the lightning protection circuit 2 is also included, and comprises a voltage dependent resistor MOV1 connected between the positive bus and the negative bus in parallel and a voltage dependent resistor NTC1 electrically connected with the negative bus, and the mains supply sequentially flows through the voltage dependent resistor MOV1 and the voltage dependent resistor NTC1 and then is output to the EMI rectification circuit 3.
The control method specifically comprises the following steps:
1. in this embodiment, the F1 is a 3.15A//250V fuse, which provides power-off protection for circuit abnormality, and the 100-240V commercial power input line 1 is input through the fuse F1.
2. In this embodiment, the MOV1 element is capable of absorbing L line to N line lightning strike energy. NTC1 is used for reducing the input surge current, prevents that the L-N input commercial power from entering into great peak current damage back stage circuit part at the moment of starting up, and MOV1 is 10S561 piezo-resistor, and NTC1 is 5D-9 thermistor.
The lightning protection circuit 222 is composed of MOV1 and NTC 1.
3. In this embodiment, after the EMI filter circuit filters the interference from the mains line, one path of the EMI filter circuit is rectified by the rectifier bridge stack BD1, and filtered by the C1 electrolytic capacitor to form a smooth dc voltage, which provides energy for the post-stage switching conversion circuit. And the other path of voltage detected by D2 and D3 at the two ends of L-N is connected to the PWEM pulse/residual voltage bleeder circuit chip through resistors R6 and R6A to provide a path for discharging voltage energy.
The EMI and rectifying filter circuit comprises an LF1 common mode inductor, a CX1 capacitor, a BD1 bridge stack and a C1 electrolytic capacitor. C1A ceramic chip capacitor, D2, D3 rectifier diode.
4. In this embodiment, the switch transformer converting circuit 4 receives the energy supplied by the previous stage from the transformer T1, the switch Q1 is controlled by the PWM chip, and when the PWM chip operates, the switch Q1 is in a high-speed on and off state, so that the transformer always operates in a state of storing and releasing energy. Meanwhile, R3, R3A, R4, R4A, C2 and D4 are used as absorption loops, and peak current voltage generated by switching pulse is absorbed.
The switching transformer conversion circuit 4 comprises resistors R3, R3A, R4, R4A, R8, R11, R12, a capacitor C2, diodes D4, D5, a switching MOS transistor Q1 and a transformer T1.
5. In this embodiment, the secondary rectifying and outputting circuit is used to convert the voltage sensed by the secondary of the switching converter circuit into a smooth and stable DC voltage required by the external device. When the switching tube is cut off, the Schottky is turned on by obtaining the released energy, and rectifies the direct current electric energy into direct current electric energy required by the secondary side, and the C5 and the C6 filter and store the energy to supply to electric equipment.
The secondary rectification and output circuit mainly comprises a Schottky diode D1, electrolytic capacitors C5 and C6, a common mode inductor LF2, absorption resistors R5 and R5A and a ceramic chip capacitor C3.
6. In this embodiment, the adjustable feedback output voltage stabilizing circuit performs resistance value conversion through the potentiometer R14 to control the TL 431U 3 to output different voltages, thereby affecting the communication between the optocoupler U2 and the PWM chip U1, and controlling the working pulse width of the switching tube, so that the switching tube always outputs different voltages adjusted and output stably by following the potentiometer R14.
The adjustable feedback output voltage stabilizing circuit comprises an optocoupler U2, a voltage stabilizing IC TL 431U 3, a resistor R9, R10, R13, R15, R16, R22, a potentiometer R14 and a capacitor C7.
7. In this embodiment, the PWM pulse and residual voltage relief circuit is the PWM pulse circuit 7, the change of the output voltage is detected by the power supply winding and the optocoupler U2, and the PWM chip U1 controls the working pulse width of the switching tube, so that the output voltage and current output always remains stable.
The PWM pulse and residual voltage bleeder circuit mainly comprises diodes D6 and D7, resistors R6, R6A, R7, R7A, R7B, R17, R18, R20, R21, capacitors C8, C9, C10 and C11, a PWM chip U1 and a power supply winding.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims (6)
1. A constant power supply with adjustable output voltage, comprising:
the system comprises a mains supply input line, a power supply output line and a power supply output line, wherein the mains supply input line comprises a positive bus and a negative bus, and the positive bus and the negative bus respectively take power from mains supply;
the switching transformer conversion circuit comprises a transformer T1 and a switching tube Q1, wherein the switching tube Q1 is connected with the output end of the lightning protection circuit to obtain electricity, alternating-current voltage of commercial power is converted into direct-current voltage and then input to one end of the primary side of the transformer T1, the other end of the primary side of the transformer T1 is connected to the controller U1 through a switching tube Q1, the secondary side of the transformer T1 is connected with external electric equipment to supply power, and an auxiliary winding on the secondary side of the transformer T1 is connected with a VCC end of the controller U1;
the adjusting feedback circuit comprises an optocoupler U2 and a potentiometer R14, the output end of a transformer T1 is divided into two branches, one end of the secondary side of the transformer T1 is connected with the ground after passing through a series resistor R9, a resistor R13 and a controllable precise voltage-stabilizing source U3 respectively, the other branch is connected with the ground after passing through a resistor R10, a resistor R15 and a resistor R22, the transmitting end of the optocoupler U2 is connected with two ends of a resistor R13 in parallel, the potentiometer R14 is connected with two ends of a resistor R15 in parallel, and a node between the resistor R22 and the resistor R15 is connected with a U3 of the controllable precise voltage-stabilizing source U3REFAnd at the end, an optical coupler U2 and a potentiometer R14 are respectively and electrically connected with the controller U1.
2. The output voltage adjustable constant power supply of claim 1, wherein the resistor R13 and the U of the controllable precision voltage regulator U3REFA capacitor C7 and a resistor R16 are connected in series between the ends.
3. The constant power supply with the adjustable output voltage according to claim 2, further comprising an EMI rectifying circuit, which branches two paths from the commercial power input line after taking the commercial power, wherein one path is rectified by a bridge rectifier BD1 and then outputted to an electrolytic capacitor C1 to be filtered into a smooth dc voltage, the dc voltage is transmitted to the switching transformer conversion circuit, the other path is used to collect the input voltage through a node between a diode D2 and a diode D3 which are connected in series in sequence, the conduction direction of the diode D2 points to the negative bus, and the conduction direction of the diode D3 points to the positive bus.
4. The output voltage adjustable constant power supply of claim 3, further comprising a secondary side rectifying and filtering output circuit, wherein the output end of the transformer T1 is connected with an external electric device for power supply after passing through a Schottky diode D1, a capacitor C5, a capacitor C6 and a common mode inductor LF2 in sequence.
5. The output voltage adjustable constant power supply of claim 4, further comprising an absorption resistor formed by connecting a resistor R5 and a resistor R5A in parallel, wherein one end of the absorption resistor is connected to the input terminal of the Schottky diode D1, and the other end is connected to the output terminal of the Schottky diode D1 through a capacitor C3.
6. The output voltage adjustable constant power supply of claim 3, further comprising a lightning protection circuit, which comprises a voltage dependent resistor MOV1 connected in parallel between the positive bus and the negative bus, and a voltage dependent resistor NTC1 electrically connected to the negative bus, wherein the commercial power sequentially flows through the voltage dependent resistor MOV1 and the voltage dependent resistor NTC1 and then is output to the EMI rectification circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123452080.9U CN216699856U (en) | 2021-12-31 | 2021-12-31 | Constant power supply with adjustable output voltage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123452080.9U CN216699856U (en) | 2021-12-31 | 2021-12-31 | Constant power supply with adjustable output voltage |
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| Publication Number | Publication Date |
|---|---|
| CN216699856U true CN216699856U (en) | 2022-06-07 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202123452080.9U Active CN216699856U (en) | 2021-12-31 | 2021-12-31 | Constant power supply with adjustable output voltage |
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| CN (1) | CN216699856U (en) |
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2021
- 2021-12-31 CN CN202123452080.9U patent/CN216699856U/en active Active
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