一种电压可调电路
By innovatively combining the Darlington structure and a self-resetting fuse, along with a three-stage amplification structure and a dynamic reference source, the problem of output current and voltage regulation in high-voltage, high-current scenarios of existing voltage-adjustable circuits is solved, achieving 10A high-current output and wide voltage regulation, suitable for power supply scenarios requiring high reliability and economy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ANYANG XIANGYU MEDICAL EQUIP
- Filing Date
- 2025-09-17
- Publication Date
- 2026-07-17
AI Technical Summary
Existing voltage-adjustable circuits suffer from limitations in the allowable voltage difference between input and output voltages and insufficient output current capability in high-voltage and high-current scenarios, making it difficult to drive loads such as lasers and high-power motors.
The circuit employs a Darlington structure and a self-resetting fuse to construct reverse connection and short circuit protection circuits. Combined with a three-stage amplification structure and a dynamic reference source, it achieves a 10A high current output. It integrates reverse connection, overcurrent, and voltage regulation protection functions and uses discrete component solutions to reduce costs.
It achieves a wide voltage regulation range and high current output capability, breaking through the limitations of traditional circuits. It is suitable for power supply scenarios with high reliability and economic requirements, especially industrial power supplies and electric vehicle simulation applications.
Smart Images
Figure CN224519205U_ABST
Abstract
Claims
1. A voltage adjustable circuit, characterized by, The circuit includes: Reverse connection protection circuit, short circuit protection circuit, Darlington output circuit, and output voltage feedback regulation circuit; The reverse connection protection circuit includes a diode D1, with the positive terminal of D1 connected to the positive terminal of the power input and the negative terminal connected to the short circuit protection circuit. The short-circuit protection circuit includes a self-resetting fuse F1, one end of which is connected to the negative terminal of D1, and the other end is connected to the Darlington output circuit. The Darlington output circuit includes transistors Q1 and Q2 and resistor R3. The collector of Q2 is connected to F1, and the base is connected to the collector of Q1 through R3. The base of Q2 is connected to the collector of Q3 in the output voltage feedback regulation circuit. The output voltage feedback regulation circuit includes a resistor R1, an adjustable resistor R2, a Zener diode D2, and a transistor Q3. R1 and R2 are connected in series and then in parallel between the emitter of Q1 and ground. The negative terminal of D2 is connected to the emitter of Q3, and the positive terminal is grounded. The collector of Q3 is connected to the base of Q2. The voltage regulator capacitor C1 is connected in parallel between the adjustable output terminal and the base of Q3, and C2 is connected in parallel between the adjustable output terminal and ground.
2. The voltage adjustable circuit according to claim 1, characterized in that: D1 is a Schottky diode. When the positive and negative terminals of the power supply are reversed, its unidirectional conductivity blocks the current and prevents the component from being damaged.
3. The voltage adjustable circuit according to claim 1, characterized in that: F1 is a 10A resettable fuse. When the output current exceeds 10A, the resistance increases exponentially, causing an open circuit. After the fault is cleared, it automatically resumes conduction.
4. The voltage adjustable circuit according to claim 1, characterized in that: Q1 and Q2 form a two-stage amplification structure. The base current of Q1 is provided by the collector current of Q2. The total amplification factor β_total = β1 × β2, where β1 is the current amplification factor of Q1 and β2 is the current amplification factor of Q2.
5. The voltage adjustable circuit according to claim 1, characterized in that: D2 is a 2.4V Zener diode. The base voltage of Q3 is clamped at V_D2 + V_BE = 2.4V + 0.7V = 3.1V. The current flowing through R1 is I_R1 = 3.1V / R1. The output voltage is V_out = (R1 + R2) × 3.1V / R1. V_D2 represents the stable voltage value across Zener diode D2, and V_BE represents the voltage drop between the base and emitter of transistor Q3.
6. The voltage adjustable circuit according to claim 1, characterized in that: Q3 is an NPN transistor. The collector current of Q3 is controlled by the base voltage. When the adjustable resistor value is increased, the base voltage of Q3 is less than 3.1V, Q3 is turned off, the base current of Q1 increases, and the output voltage increases. When the base voltage of Q3 reaches 3.1V, the output voltage stabilizes. When the adjustable resistor value is decreased, the base current of Q3 increases, the conduction degree of Q3 increases, the base current of Q1 decreases, and the output voltage decreases. When the base voltage of Q3 reaches 3.1V, the output voltage stabilizes.
7. The voltage adjustable circuit according to claim 1, characterized in that: R3 is a 2kΩ resistor connected between the collector and base of Q2 to limit the base current of Q1 and stabilize the operating point.
8. The voltage adjustable circuit according to claim 1, characterized in that: C1 is a 100μF electrolytic capacitor, C2 is a 1000μF electrolytic capacitor, the voltage regulator C1 is connected in parallel between the adjustable output terminal and the base of Q3, and C2 is connected in parallel between the adjustable output terminal and ground to suppress output voltage fluctuations.
9. The voltage adjustable circuit according to claim 1, characterized in that: The input voltage range is 5V-58V, and the continuously adjustable output voltage range is 3.1V-(R1+R2_max)×3.1V / R1, where R2_max is the maximum resistance value of the adjustable resistor R2.
10. The voltage-adjustable circuit according to claim 1, characterized in that: The Darlington structure achieves small current control of large current through two-stage amplification. When the load current is I0, the base current of Q2 is Ib2=I0 / (β1×β2), and the base current of Q1 is Ib1=Ib2×β2.