Voltage-stabilizing power supply circuit with wide input range

By using a voltage divider stabilizing circuit of transistors Q1 and Q2 in a voltage stabilizing power supply circuit, the problem of current overload of the voltage stabilizing diode is solved, the output of the stabilizing voltage is achieved, the cost is reduced, and the power density is improved.

CN223321964UActive Publication Date: 2025-09-09HUIZHOU SANHUA IND
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Patent Information

Application Number
CN202422058802.X
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-08-23
Publication Date
2025-09-09
Estimated Expiration
2034-08-23

AI Technical Summary

Technical Problem

In the prior art, under a wide range of input voltages, the current of the Zener diode easily exceeds the maximum operating current, causing damage. Replacing the high-current Zener diode increases material costs and occupies space, and reduces power density.

Method used

Transistor Q1 is used as the load, and Zener diode ZD1 is placed at the base of transistor Q2. Large current is borne by the collector and emitter of transistor Q2. Transistors and Zener diodes with smaller packages are used, combined with rectification and filtering circuits and voltage divider and voltage stabilization circuits to achieve voltage stability.

Benefits of technology

This effectively reduces production costs, while preventing damage to the Zener diode and outputting a stable VCC voltage, thereby improving power density.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses a voltage stabilization power supply circuit with a wide input range. The voltage stabilization power supply circuit comprises a transformer VCC winding, a rectification filter circuit, a resistor R1, a triode Q1, a voltage dividing and stabilizing circuit and a VCC output end. When a transformer VCC winding generates voltage, the voltage passes through the R1 and drives the triode Q1 to be conducted after being rectified and filtered, the conducted voltage passes through the voltage stabilizing diode ZD1, the resistor R2 and the resistor R3 and drives the triode Q2 to be conducted, and at the moment, a voltage stabilizing loop is completed. Compared with a traditional wide-range voltage-stabilizing power supply circuit, the wide-range voltage-stabilizing power supply circuit has the advantages that the voltage-stabilizing diode ZD1 with smaller current resistance is placed on the base electrode of the triode Q2, and larger current of a voltage-stabilizing loop is borne by the collector electrode and the emitter electrode of the triode Q2, so that the triode and the voltage-stabilizing diode which are smaller in package can be used, and the production cost is reduced.
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Description

Technical Field

[0001] The utility model relates to the technical field of power supply circuits, in particular to a voltage-stabilized power supply circuit with a wide input range. Background Art

[0002] When the chip starts up, its VCC pin needs to be powered. In the design of switching power supply, a set of VCC windings are usually wound around the transformer to power the chip.

[0003] refer to Figure 1 In the prior art, under a wide input voltage range, the voltage generated by the transformer VCC winding is rectified and filtered to a voltage range of 24V-42V. Directly applying this voltage to the chip will burn it out. To avoid damaging the chip, transistor Q1, voltage regulator diode ZD1, and resistor R1 are added to stabilize its voltage within the power supply safety voltage.

[0004] However, there is a problem in the above-mentioned prior art. When the rectifier voltage is too high, the current of the Zener diode ZD1 will exceed its maximum operating current. The current of the SOD123 package is about 5mA. In order to prevent it from being damaged, a Zener diode with a larger current can only be used. However, replacing the Zener diode with a larger current will significantly increase the production material cost and occupy more circuit board space, resulting in a decrease in power density. Utility Model Content

[0005] In view of this, the utility model provides a voltage-stabilized power supply circuit with a wide input range.

[0006] The embodiment of the utility model provides a voltage-stabilized power supply circuit with a wide input range, comprising: a transformer VCC winding, a rectifier filter circuit, a resistor R1, a transistor Q1, a voltage-dividing and stabilizing circuit, and a VCC output terminal;

[0007] The voltage generated by the transformer VCC winding drives the transistor Q1 to conduct after passing through the rectifier and filter circuit;

[0008] The base of the transistor Q1 is connected to the rectifier and filter circuit through the resistor R1, the collector of the transistor Q1 is connected to the rectifier and filter circuit, and the emitter of the transistor Q1 is connected to the voltage divider and stabilizing circuit and the VCC output terminal respectively;

[0009] The voltage divider and stabilizing circuit includes a voltage stabilizing diode ZD1, resistors R2, R3 and a transistor Q2;

[0010] The cathode of the voltage stabilizing diode ZD1 is connected to the emitter of the transistor Q1, and the anode of the voltage stabilizing diode ZD1 is connected to the resistor R2 and the resistor R3 and then grounded;

[0011] The base of the transistor Q2 is connected between the resistors R2 and R3 , the emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is connected to the base of the transistor Q1 .

[0012] As a preferred embodiment of the present invention, the rectifier and filter circuit includes a diode D1;

[0013] One end of the transformer VCC winding is connected to the positive electrode of the diode D1, and the other end of the transformer VCC winding is grounded;

[0014] The cathode of the diode D1 is connected to the collector of the transistor Q1 .

[0015] As a preferred embodiment of the present invention, the rectifier and filter circuit further includes an electrolytic capacitor CE1;

[0016] One end of the electrolytic capacitor CE1 is connected to the collector of the transistor Q1 , and the other end of the electrolytic capacitor CE1 is grounded.

[0017] As a preferred embodiment of the present invention, the rectifier and filter circuit further includes a capacitor C1;

[0018] One end of the capacitor C1 is connected to the collector of the transistor Q1 , and the other end of the capacitor C1 is grounded.

[0019] As a preferred embodiment of the present invention, the transistor Q1 is an NPN transistor.

[0020] As a preferred embodiment of the present invention, the transistor Q2 is an NPN transistor.

[0021] As a preferred embodiment of the present invention, the voltage stabilization value of the voltage stabilizing diode is 15V.

[0022] As a preferred embodiment of the present invention, the resistance of the resistor R1 is 2.2KΩ.

[0023] As a preferred embodiment of the present invention, the resistance of the resistor R2 is 10KΩ.

[0024] As a preferred embodiment of the present invention, the resistance of the resistor R3 is 20KΩ.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] In the embodiment of the present invention, through the above-described technical solution, when the voltage generated by the transformer VCC winding is rectified and filtered, it passes through R1 and drives transistor Q1 to conduct. After conduction, the voltage passes through Zener diode ZD1, resistors R2, and resistor R3, driving transistor Q2 to conduct, thus completing the voltage stabilization circuit. Compared to traditional wide-range voltage-stabilized power supply circuits, the circuit of the present invention places the Zener diode ZD1, which has a lower current tolerance, at the base of transistor Q2. The larger current of the voltage stabilization circuit is borne by the collector and emitter of transistor Q2. Therefore, smaller transistors and Zener diodes can be used, thereby reducing production costs.

[0027] With the above technical solution, when the voltage across Zener diode ZD1 exceeds its regulated voltage (e.g., 15V), the excess voltage, through Zener diode ZD1, resistors R2, and R3, drives the base of transistor Q2 into conduction, turning its collector low. Simultaneously, the base voltage of transistor Q1 decreases, and the emitter voltage of transistor Q1 also decreases. Similarly, when the voltage across Zener diode ZD1 is low, the base voltage of transistor Q2 decreases, the collector voltage of transistor Q2 increases, the base voltage of transistor Q1 increases, and the emitter voltage of transistor Q1 also increases. This protects the Zener diode from damage due to high current while also providing a stable VCC output. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0029] Figure 1 It is a circuit diagram of a voltage-stabilized power supply circuit in the prior art;

[0030] Figure 2 This is a circuit diagram of a voltage-regulated power supply circuit with a wide input range according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] Example:

[0033] like Figure 2 As shown, the embodiment of the present invention provides a voltage-stabilized power supply circuit with a wide input range, comprising: a transformer VCC winding 10, a rectifier filter circuit 20, a resistor R1, a transistor Q1, a voltage-dividing and stabilizing circuit 30, and a VCC output terminal 40;

[0034] The voltage generated by the transformer VCC winding 10 drives the transistor Q1 to conduct after passing through the rectifier and filter circuit 20;

[0035] The base of the transistor Q1 is connected to the rectifier and filter circuit 20 through the resistor R1, the collector of the transistor Q1 is connected to the rectifier and filter circuit 20, and the emitter of the transistor Q1 is connected to the voltage divider and stabilization circuit 30 and the VCC output terminal 40 respectively;

[0036] The voltage divider and stabilizing circuit 30 includes a voltage stabilizing diode ZD1, resistors R2, R3 and a transistor Q2;

[0037] The cathode of the voltage stabilizing diode ZD1 is connected to the emitter of the transistor Q1, and the anode of the voltage stabilizing diode ZD1 is connected to the resistor R2 and the resistor R3 and then grounded;

[0038] The base of the transistor Q2 is connected between the resistors R2 and R3 , the emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is connected to the base of the transistor Q1 .

[0039] The embodiment of the present invention is configured with the above-mentioned technical solution. First, transistor Q1 is used as a load. The loss after conduction is VCE voltage drop * load current. Under the same conditions, the use of transistor Q1 can effectively reduce the loss of resistor R1. Secondly, when the transformer VCC winding generates voltage, after rectification and filtering, it will pass through R1 and drive transistor Q1 to conduct. After conduction, the voltage passes through the voltage-stabilizing diode ZD1, resistor R2, and resistor R3, and drives transistor Q2 to conduct. At this time, the voltage-stabilizing circuit is completed. Compared with the traditional wide-range voltage-stabilizing power supply circuit, the circuit in the present invention places the voltage-stabilizing diode ZD1 with a smaller current resistance at the base of the transistor Q2. The larger current of the voltage-stabilizing circuit is borne by the collector and emitter of the transistor Q2. Therefore, transistors and voltage-stabilizing diodes with smaller packages can be used, thereby reducing production costs.

[0040] As a preferred embodiment of the present invention, the rectifier and filter circuit 20 includes a diode D1;

[0041] One end of the transformer VCC winding 10 is connected to the positive electrode of the diode D1, and the other end of the transformer VCC winding 10 is grounded;

[0042] The cathode of the diode D1 is connected to the collector of the transistor Q1 .

[0043] The diode D1 is used for rectification and can convert alternating current into pulsating direct current.

[0044] As a preferred embodiment of the present invention, the rectifier and filter circuit 20 further includes an electrolytic capacitor CE1;

[0045] One end of the electrolytic capacitor CE1 is connected to the collector of the transistor Q1 , and the other end of the electrolytic capacitor CE1 is grounded.

[0046] The electrolytic capacitor CE1 is used for filtering. To prevent the supply voltage of each part of the circuit from changing due to load changes, a larger electrolytic capacitor CE1 is connected after rectification. Its charge and discharge characteristics can be used to convert the pulsating DC voltage after rectification into a relatively stable DC voltage.

[0047] As a preferred embodiment of the present invention, the rectifier and filter circuit 20 further includes a capacitor C1;

[0048] One end of the capacitor C1 is connected to the collector of the transistor Q1 , and the other end of the capacitor C1 is grounded.

[0049] The capacitor C1 is used for filtering. Since the electrolytic capacitor CE1 has a certain inductance and cannot effectively filter out high-frequency and pulse interference signals, the capacitor C1 is connected in parallel at both ends to filter out high-frequency and pulse interference.

[0050] As a preferred embodiment of the present invention, the transistor Q1 is an NPN transistor.

[0051] As a preferred embodiment of the present invention, the transistor Q2 is an NPN transistor.

[0052] As a preferred embodiment of the present invention, the voltage stabilization value of the voltage stabilizing diode is 15V.

[0053] In the embodiment of the present invention, the transformer VCC winding 10 generates a voltage, which is rectified and filtered. The voltage after rectification and filtering is between 24-42V for different input voltages and different output loads. A voltage stabilizing diode with a voltage stabilizing value of 15V can play a good voltage stabilizing role.

[0054] As a preferred embodiment of the present invention, the resistance of the resistor R1 is 2.2KΩ.

[0055] As a preferred embodiment of the present invention, the resistance of the resistor R2 is 10KΩ.

[0056] As a preferred embodiment of the present invention, the resistance of the resistor R3 is 20KΩ.

[0057] The resistors R1, R2, and R3 are configured such that when the voltage across the Zener diode ZD1 exceeds its regulated voltage value (e.g., 15V), the excess voltage, through the Zener diode ZD1, resistors R2, and R3, drives the base of transistor Q2 to conduct, causing its collector to go low. Simultaneously, the base voltage of transistor Q1 decreases, and the emitter voltage of transistor Q1 also decreases accordingly. Similarly, when the voltage across the Zener diode ZD1 is low, the base voltage of transistor Q2 decreases, the collector voltage of transistor Q2 increases, the base voltage of transistor Q1 increases, and the emitter voltage of transistor Q1 also increases accordingly.

[0058] The circuit working principle of this utility model is as follows:

[0059] 1. Composition of the voltage stabilizing circuit: When the transformer VCC winding generates voltage, after rectification and filtering, it will pass through R1 and drive the transistor Q1 to turn on. After conduction, the voltage passes through the voltage stabilizing diode ZD1, resistor R2, and resistor R3, which will drive the transistor Q2 to turn on. At this time, the voltage stabilizing circuit is completed.

[0060] Compared with the traditional wide-range voltage-stabilized power supply circuit, the circuit of the present invention places the voltage-stabilizing diode ZD1 with a smaller current resistance at the base of the transistor Q2. The larger current of the voltage-stabilizing loop is borne by the collector and emitter of the transistor Q2. Therefore, smaller-packaged transistors and voltage-stabilizing diodes can be used, thereby reducing production costs.

[0061] 2. Voltage stabilization process: When the voltage passing through the Zener diode ZD1 exceeds its regulated value (e.g., 15V), the excess voltage will drive the base of transistor Q2 to conduct through the Zener diode ZD1, resistors R2, and resistor R3, and its collector will become low. At the same time, the base voltage of transistor Q1 decreases, and the emitter voltage of transistor Q1 also decreases accordingly. Similarly, when the voltage passing through the Zener diode ZD1 is low, the base voltage of transistor Q2 decreases, the collector voltage of transistor Q2 increases, the base voltage of transistor Q1 increases, and the emitter voltage of transistor Q1 also increases accordingly.

[0062] In summary, the circuit in the embodiment of the present invention can output a stable VCC voltage while preventing the Zener diode from being damaged due to high current.

[0063] The above is only a preferred embodiment of the present utility model patent, but the protection scope of the present utility model patent is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the scope disclosed by the present utility model patent based on the technical solution and utility model concept of the present utility model patent, which falls within the protection scope of the present utility model patent.

Claims

1. A voltage-stabilized power supply circuit with a wide input range, characterized in that: include: Transformer VCC winding, rectifier filter circuit, resistor R1, transistor Q1, voltage divider and voltage stabilization circuit and VCC output terminal; The voltage generated by the transformer VCC winding drives the transistor Q1 to conduct after passing through the rectifier and filter circuit; The base of the transistor Q1 is connected to the rectifier and filter circuit through the resistor R1, the collector of the transistor Q1 is connected to the rectifier and filter circuit, and the emitter of the transistor Q1 is connected to the voltage divider and stabilizing circuit and the VCC output terminal respectively; The voltage divider and stabilizing circuit includes a voltage stabilizing diode ZD1, resistors R2, R3 and a transistor Q2; The cathode of the voltage stabilizing diode ZD1 is connected to the emitter of the transistor Q1, and the anode of the voltage stabilizing diode ZD1 is connected to the resistor R2 and the resistor R3 and then grounded; The base of the transistor Q2 is connected between the resistors R2 and R3 , the emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is connected to the base of the transistor Q1 .

2. The voltage-stabilized power supply circuit with a wide input range according to claim 1, characterized in that: The rectifier and filter circuit includes a diode D1; One end of the transformer VCC winding is connected to the positive electrode of the diode D1, and the other end of the transformer VCC winding is grounded; The cathode of the diode D1 is connected to the collector of the transistor Q1 .

3. The voltage-stabilized power supply circuit with a wide input range according to claim 2, characterized in that: The rectifier and filter circuit further includes an electrolytic capacitor CE1; One end of the electrolytic capacitor CE1 is connected to the collector of the transistor Q1 , and the other end of the electrolytic capacitor CE1 is grounded.

4. The voltage-stabilized power supply circuit with a wide input range according to claim 3, characterized in that: The rectifier and filter circuit further includes a capacitor C1; One end of the capacitor C1 is connected to the collector of the transistor Q1 , and the other end of the capacitor C1 is grounded.

5. The voltage-stabilized power supply circuit with a wide input range according to claim 1, characterized in that: The transistor Q1 is an NPN transistor.

6. The voltage-stabilized power supply circuit with a wide input range according to claim 1, characterized in that: The transistor Q2 is an NPN transistor.

7. The voltage-stabilized power supply circuit with a wide input range according to claim 1, characterized in that: The voltage stabilization value of the voltage stabilizing diode is 15V.

8. The voltage-stabilized power supply circuit with a wide input range according to claim 7, characterized in that: The resistance of the resistor R1 is 2.2KΩ.

9. The voltage-stabilized power supply circuit with a wide input range according to claim 8, characterized in that: The resistance of the resistor R2 is 10KΩ.

10. The voltage-stabilized power supply circuit with a wide input range according to claim 9, characterized in that: The resistance of the resistor R3 is 20KΩ.