A multi-mode voltage conversion charging protection circuit for a mobile power supply
Patent Information
- Application Number
- CN202522085869.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-28
- Publication Date
- 2026-09-04
- Estimated Expiration
- 2035-09-28
AI Technical Summary
现有技术中，虽然有一些电压转换电路可以实现不同电压的输出，但往往无法满足不同模式下的高效充电和保护需求，且电路设计较为复杂，成本较高
采用555定时器的自激模式生成PWM信号，通过合理设计电感器、第一电容和开关元件，使得电路能够在多种工作模式下实现高效的电压转换和稳定的电力输出。这种设计不仅提高了电池的充电效率，还能在不同电压需求的设备间提供兼容性，满足了用户在不同环境下对电源的需求。
Smart Images
Figure CN224721626U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of charging circuit technology, and in particular to a multi-mode voltage conversion charging protection circuit for mobile power supplies. Background Technology
[0002] With the widespread use of mobile electronic devices, power banks, as convenient power replenishment devices, have become an indispensable part of people's daily lives. Traditional power banks typically use a single voltage output and often lack charging protection functions, making them prone to overcharging, over-discharging, and short circuits, leading to shortened battery life or safety accidents. Therefore, how to achieve more intelligent voltage conversion and charging protection has become a key issue in improving the performance of power banks. In existing technologies, although some voltage conversion circuits can achieve different voltage outputs, they often cannot meet the needs of efficient charging and protection in different modes, and the circuit design is relatively complex and costly. Summary of the Invention
[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a multi-mode voltage conversion charging protection circuit for mobile power banks. It aims to generate a PWM signal through a self-excited mode, which, in conjunction with an inductor and switching elements, achieves voltage conversion and protection under different modes. It features high power conversion efficiency, effectively protects the battery from overcharging and over-discharging damage, and is simple in design and low in cost, making it suitable for the development of various mobile power bank products.
[0004] To achieve the above objectives, the following solution is adopted: A multi-mode voltage conversion charging protection circuit for a portable power bank includes: A 555 timer, configured in self-oscillating mode and configured to generate a PWM signal via a first resistor, a second resistor, and a first capacitor; An inductor, one end of which is connected to the power supply terminal of the 555 timer, and the other end of which is connected to the anode of the output diode, the cathode of which is connected to the circuit output terminal; The switching element is selected as an N-channel MOSFET, whose gate is connected to the output terminal of the 555 timer, whose source is connected between the inductor and the output diode, and whose drain is connected to ground; An output capacitor is connected between the cathode of the output diode D and the output terminal.
[0005] Furthermore, one end of the first resistor is connected to the reset terminal of the 555 timer and the power supply terminal, and the other end of the first resistor is connected to the anode of the first diode, the cathode of the second diode, and the discharge terminal of the 555 timer. One end of the second resistor is connected to the threshold terminal and the trigger terminal of the 555 timer and the first capacitor, and the other end of the second resistor is connected to the adjustment terminal of the variable resistor. The two ends of the variable resistor are respectively connected to the cathode of the first diode and the anode of the second diode. The first capacitor is grounded.
[0006] Furthermore, the control terminal of the 555 timer is connected to the second capacitor, which is grounded.
[0007] Furthermore, the power supply terminal is also connected to a 5-12V power supply.
[0008] By adopting the above solution, the beneficial effects of this utility model are: The circuit utilizes a 555 timer in self-oscillating mode to generate PWM signals. Through the rational design of the inductor, first capacitor, and switching components, it achieves efficient voltage conversion and stable power output in various operating modes. This design not only improves battery charging efficiency but also provides compatibility between devices with different voltage requirements, meeting users' power needs in diverse environments. Attached Figure Description
[0009] Figure 1 This is a schematic diagram of the multi-mode voltage conversion charging protection circuit for mobile power supply according to this utility model. Detailed Implementation
[0010] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0011] Reference Figure 1 As shown, this utility model provides a multi-mode voltage conversion charging protection circuit for a mobile power bank, including: 555 timer U1 is configured in self-oscillating mode and is configured to generate PWM signals through first resistor R1, second resistor R2 and first capacitor C1; Inductor L1, one end of inductor L1 is connected to the power supply terminal of 555 timer U1, and the other end is connected to the anode of output diode D3. The cathode of output diode D3 is connected to the circuit output terminal. Switching element Q1 is selected as an N-channel MOSFET, with its gate connected to the output of the 555 timer, its source connected between inductor L1 and output diode D3, and its drain connected to ground. Output capacitor C3 is connected between the cathode of output diode D3D and the output terminal.
[0012] Specifically, one end of the first resistor R1 is connected to the reset terminal and the power supply terminal of the 555 timer U1, and the other end of the first resistor R1 is connected to the anode of the first diode D1, the cathode of the second diode D2, and the discharge terminal of the 555 timer. One end of the second resistor R2 is connected to the threshold terminal and the trigger terminal of the 555 timer U1 and the first capacitor C1, and the other end of it is connected to the adjustment terminal of the variable resistor POT. The two ends of the variable resistor POT are respectively connected to the cathode of the first diode D1 and the anode of the second diode D2. The first capacitor C1 is grounded.
[0013] The control terminal of the 555 timer U1 is connected to the second capacitor C2, which is grounded.
[0014] The power supply is also connected to a 5-12V power supply.
[0015] Working principle: The RESET port of the 555 timer U1 is the reset terminal; a low level resets the timer. The DISCH port is the discharge terminal, used to control the capacitor's discharge process. The THRES port is the threshold terminal; the timer output changes when the voltage reaches 2 / 3 of Vcc. The TRIG port is the trigger terminal; the timer output changes when the voltage drops below 1 / 3 of Vcc. The GND port is the ground terminal, connected to ground. The VCC port is the power supply terminal, providing the timer's operating voltage. The OUT port is the output terminal, outputting the timer's status signal. The CONT port is the control terminal; connecting a capacitor reduces noise interference.
[0016] During operation, the 555 timer U1 is configured in self-oscillating mode. The frequency of the PWM signal is determined by the first resistor R1, the second resistor R2, and the first capacitor C1. The duty cycle of the PWM signal determines the on and off time of the switching element Q1, which is crucial for controlling the output voltage and enabling boost voltage in different modes. The inductor stores energy when the switching element Q1 is on, and releases the stored energy when the switching element Q1 is off, flowing to the output capacitor and the load through the output diode D3.
[0017] In this circuit, the first diode D1 ensures that the current flows in the correct direction and prevents current backflow. The output capacitor smooths the voltage, ensuring a stable DC output. The load connected to the circuit output receives the boosted voltage, and the output voltage depends on the duty cycle of the PWM signal and the input voltage.
[0018] In summary, this invention uses a 555 timer in self-oscillating mode to generate a PWM signal. Through the rational design of inductor L1, first capacitor C1, and switching element Q1, the circuit achieves efficient voltage conversion and stable power output in various operating modes. This design not only improves battery charging efficiency but also provides compatibility between devices with different voltage requirements, meeting users' power needs in various environments.
[0019] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A multi-mode voltage conversion charging protection circuit for a mobile power bank, characterized in that, include: A 555 timer, configured in self-oscillating mode and configured to generate a PWM signal via a first resistor, a second resistor, and a first capacitor; An inductor, one end of which is connected to the power supply terminal of the 555 timer, and the other end of which is connected to the anode of the output diode, the cathode of which is connected to the circuit output terminal; The switching element is selected as an N-channel MOSFET, with its gate connected to the output of the 555 timer, its source connected between the inductor and the output diode, and its drain connected to ground. An output capacitor is connected between the cathode of the output diode D and the output terminal.
2. The mobile power bank multi-mode voltage conversion charging protection circuit according to claim 1, characterized in that, One end of the first resistor is connected to the reset terminal of the 555 timer and the power supply terminal. The other end of the first resistor is connected to the anode of the first diode, the cathode of the second diode, and the discharge terminal of the 555 timer. One end of the second resistor is connected to the threshold terminal and the trigger terminal of the 555 timer and the first capacitor. The other end of the second resistor is connected to the adjustment terminal of the variable resistor. The two ends of the variable resistor are respectively connected to the cathode of the first diode and the anode of the second diode. The first capacitor is grounded.
3. The mobile power supply multi-mode voltage conversion charging protection circuit according to claim 1, characterized in that, The control terminal of the 555 timer is connected to the second capacitor, which is grounded.
4. The mobile power bank multi-mode voltage conversion charging protection circuit according to claim 1, characterized in that, The power supply terminal is also connected to a 5-12V power supply.