Low-voltage power supply circuit and power supply protection chip of top flow machine system

Abstract

The utility model discloses a low pressure power supply circuit of top flow machine system, including BUCK type circuit, BUCK type circuit includes power supply chip U1, still include with first protection circuit who is connected to BUCK type circuit, and first protection circuit includes detection subcircuit, first switching device, second switching device and partial pressure circuit, detection subcircuit is used to detect the current of BUCK type circuit output, and exports detection signal, first switching device receives detection signal, and is controlled to detection signal triggers its on / off, after first switching device conduction, enter amplification stage, partial pressure circuit is connected with first switching device, second switching device still with the enablement of power supply chip U1 is connected, is used to active pull -down U1's enable, thereby completely shuts off output, to protect that circuit will not suffer fatal damage, the utility model improves the response speed to protection circuit, realizes quick overcurrent protection.

Description

Technical Field

[0001] This utility model belongs to the field of low-voltage power supply circuit technology, specifically, it relates to a low-voltage power supply circuit and power supply protection chip for a top current machine system. Background Technology

[0002] A top-current propeller system is a device used in the marine industry. It is fixed to the bow of the ship, and its underwater-extending propeller can rotate 360°. Utilizing positioning capabilities and related algorithms, it accurately senses the speed and direction of the water flow, using the propeller to generate reverse thrust to compensate for positional shifts caused by the water flow, thus ensuring the ship remains stationary. The entire top-current propeller system comprises multiple components, including propulsion, attitude control, GPS positioning, switching processing, and Bluetooth communication. Since each component receives low-voltage input, a power circuit is needed to convert the battery voltage into a stable low-voltage power supply to power each component.

[0003] Most power converters with a power output of 1kW or higher on the market use 24V or 36V or higher power supplies. However, the system is usually 12V, and the core components of each part of the system require power of 5V or less, thus requiring voltage step-down. Generally, manufacturers, for cost reasons, use a simple BUCK-type DC-DC circuit to step down the battery voltage. Without overcurrent protection, if a component in the power converter system fails or there is a short circuit between wiring harnesses, the DC-DC circuit can easily be damaged, causing the entire system to fail and resulting in high repair costs.

[0004] To address the aforementioned overcurrent protection problem, current solutions utilize the built-in overcurrent protection function of the power supply chip in the DC-DC circuit. However, this approach has other drawbacks. For instance, chips with rapid overcurrent response capabilities are expensive, while ordinary chips have slow feedback on overcurrent, often relying on internal thermal detection circuits. In the event of a sudden large current surge, the chip's internal circuitry may be damaged before the protection system activates, resulting in long response times and untimely protection failure. Therefore, a low-cost and effective protection circuit based on a BUCK-type circuit is needed. Utility Model Content

[0005] To address the shortcomings of existing technologies and improve the response speed of protection circuits, achieving rapid overcurrent protection, this utility model provides a low-voltage power supply circuit for a top-flow machine system. The circuit includes a BUCK-type circuit, which comprises a power chip U1, and a first protection circuit connected to the BUCK-type circuit. This first protection circuit includes a detection sub-circuit, a first switching device, a second switching device, and a voltage divider circuit.

[0006] The detection sub-circuit is used to detect the current output by the BUCK-type circuit and output a detection signal. The first switching device receives the detection signal and is controlled by the detection signal to turn on / off; after the first switching device is turned on, it enters the amplification stage. The first switching device is a PNP transistor Q1, and the detection sub-circuit includes detection resistors R1 and R2; the Ve terminal of the PNP transistor Q1 is connected in parallel with one end of detection resistor R1 and one end of detection resistor R2, the Vb terminal is connected in series with resistor R5 and then in parallel with the other end of detection resistor R1 and the other end of detection resistor R2 to serve as the protected 12V, and the Vc terminal is connected to the voltage divider circuit.

[0007] The voltage divider circuit is connected to the first switching device. The voltage divider circuit is configured to trigger the second switching device to conduct, entering an amplification state, based on the voltage division value detected after the first switching device is turned on. The second switching device includes an NPN transistor Q2, and the voltage divider circuit includes voltage divider resistors R11 and R13. The Vc terminal of the PNP transistor Q1 is connected in series with voltage divider resistors R11 and R13 and then grounded; the Vb and Ve terminals of the NPN transistor Q2 are connected in parallel with voltage divider resistor R13 and capacitor C10, with the Ve terminal grounded, and the Vc terminal is connected in series with R9 and then connected to the enable terminal of U1.

[0008] The second switching device is also connected to the enable terminal of the power chip U1 to actively pull down the enable of U1, thereby completely shutting off the output and protecting the circuit from fatal damage. Additionally, a second protection circuit is included, comprising a protection resistor R14 and a capacitor C11. The protection resistor R14 and capacitor C11 are connected in series between the enable terminal of U1 and ground. By actively pulling down the enable of U1 through the second protection circuit, the output is completely shut off, protecting the circuit from fatal damage.

[0009] The beneficial effects of the low-voltage power supply circuit of the top flow machine system in this utility model are as follows: 1. Based on the existing BUCK type circuit, a first protection circuit is added. The added first protection circuit only requires two ordinary transistors, a few capacitors and resistors, and the embedded software resources of the MCU. It is low in cost, easy to implement, and provides reliable protection.

[0010] 2. The resistor can be quickly replaced according to different conditions to change the protection threshold, meet the power requirements of other specifications of the top flow machine system, and be flexibly adjusted as needed, with a wide range of applications.

[0011] 3. The hardware protection speed of the first protection circuit is fast, reaching the level of hundreds of nanoseconds, giving the software sufficient reaction time and greatly reducing the probability of the chip being burned out. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a circuit diagram of the low-voltage power supply circuit of the top flow machine system in this utility model. Detailed Implementation

[0014] In view of the shortcomings of the prior art, the inventor of this utility model has, through long-term research and extensive practice, proposed the technical solution of this utility model. The following will further explain and illustrate the technical solution, its implementation process, and its principles in conjunction with the accompanying drawings and specific implementation examples.

[0015] like Figure 1 As shown, Embodiment 1 provides a low-voltage power supply circuit for a top-flow generator system, including a BUCK-type circuit, specifically a 12V-DCDC circuit. The BUCK-type circuit includes a power chip U1, which is responsible for stepping down the conventional 24V or higher battery voltage to 12V before outputting. Pin 3 of the power chip U1 is the enable pin; when its input is greater than 2V, U1 operates normally and outputs the voltage; if the voltage is lower than 1.8V, the output of U1 will be cut off. Typically, an MCU main control chip using a 3.3V power supply will control the activation of U1. The second protection circuit corresponding to the MCU main control chip includes a protection resistor R14 and a capacitor C11. The protection resistor R14 and capacitor C11 are connected in series between the enable pin of U1 and ground. By actively pulling down the enable pin of U1 through the second protection circuit, the output is completely shut off, preventing fatal damage to the protection circuit.

[0016] This embodiment also includes a first protection circuit connected to the BUCK-type circuit. The first protection circuit includes a detection sub-circuit and a first switching device. The detection sub-circuit is used to detect the current output by the BUCK-type circuit and output a detection signal. The first switching device receives the detection signal and is controlled by the detection signal to turn on / off. Specifically, after the first switching device is turned on, it enters the amplification stage. The first switching device is a PNP transistor Q1. The detection sub-circuit includes detection resistors R1 and R2. The Ve terminal of the PNP transistor Q1 is connected in parallel with one end of detection resistor R1 and one end of detection resistor R2. The Vb terminal is connected in series with resistor R5 and then in parallel with the other end of detection resistor R1 and the other end of detection resistor R2 to serve as the protected 12V. The Vc terminal is connected to the voltage divider circuit. R1 and R2 are detection resistors used to detect the current output by the 12V-DCDC circuit. Q1 is a PNP transistor. According to Ohm's law, when the current flowing through R1 and R2 exceeds the set value, the voltage formed in R1 and R2 will also exceed the BE turn-on voltage of Q1. Then, the CE terminal of Q1 starts to conduct and enters the amplification state.

[0017] The first protection circuit also includes a second switching device and a voltage divider circuit. The voltage divider circuit is connected to the first switching device and is configured to trigger the second switching device to conduct and enter an amplification state based on the voltage division value detected after the first switching device is turned on. The second switching device includes an NPN transistor Q2, and the voltage divider circuit includes voltage divider resistors R11 and R13. The Vc terminal of the PNP transistor Q1 is connected in series with voltage divider resistors R11 and R13 and then grounded; the Vb and Ve terminals of the NPN transistor Q2 are connected in parallel with voltage divider resistor R13 and capacitor C10, with the Ve terminal grounded, and the Vc terminal is connected in series with R9 and then connected to the enable terminal of U1. For feedback signal, the second switching device is also connected to the enable terminal of the power chip U1 to actively pull down the enable of U1, thereby completely shutting off the output to protect the circuit from fatal damage. As the voltage at pin 3 of Q1 (the collector) gradually increases, the voltage divider formed by resistors R11 and R13 reaches the turn-on voltage (BE) of the NPN transistor Q2. At this point, the collector and emitter of Q2 begin to conduct, entering amplification mode. As the voltage at pin 3 of Q2 gradually decreases, resistor R9 pulls the enable pin of chip U1 low, directly shutting off the output of chip U1 in hardware, preventing further temperature increases within U1. Simultaneously, as the voltage at pin 3 enters a lower level, this state notifies the MCU, prompting it to actively pull down the enable pin of U1 before the output current begins to oscillate repeatedly. This completely shuts off the output, protecting the circuit from fatal damage.

[0018] The low-voltage power supply circuit of the top flow machine system provided in this embodiment has added hardware protection speed, which can achieve protection at the level of hundreds of nanoseconds, giving the software sufficient response time.

[0019] In this embodiment, the low-voltage power supply circuit of the top-current generator system can be packaged into a power supply protection chip for the top-current generator system. This overcomes the technical deficiency of existing DC-DC power supply chips, where the current protection logic detects the internal temperature of the chip rather than the current flowing through it. This eccentric design can directly and completely shut down the output when the overcurrent value is extremely high, greatly reducing the probability of burnout.

[0020] It should be understood that the above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. It should not be considered that the specific implementation of this utility model is limited to these descriptions. For those skilled in the art to which this utility model pertains, several simple deductions or substitutions can be made without departing from the concept of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the protection scope of this utility model.

Claims

1. A low-voltage power supply circuit for a top-flow generator system, comprising a BUCK-type circuit, wherein the BUCK-type circuit includes a power supply chip U1, characterized in that: It also includes a first protection circuit connected to the BUCK-type circuit, the first protection circuit including a detection sub-circuit, a first switching device, a second switching device and a voltage divider circuit; The detection sub-circuit is used to detect the current output by the BUCK type circuit and output a detection signal; The first switching device receives the detection signal and is controlled by the detection signal to turn on or off; after the first switching device is turned on, it enters the amplification stage; The voltage divider circuit is connected to the first switching device; the voltage divider circuit is configured to trigger the second switching device to turn on and enter the amplification state based on the voltage division value detected after the first switching device is turned on. The second switching device is also connected to the enable terminal of the power chip U1 to actively pull down the enable of U1, thereby completely shutting off the output to protect the circuit from fatal damage.

2. A low voltage power supply circuit for a top stream machine system according to claim 1, characterized in that: The first switching device is a PNP transistor Q1, and the detection sub-circuit includes a detection resistor R1 and a detection resistor R2; The Ve terminal of the PNP transistor Q1 is connected in parallel with one end of the sensing resistor R1 and one end of the sensing resistor R2. The Vb terminal is connected in series with the resistor R5 and then in parallel with the other end of the sensing resistor R1 and the other end of the sensing resistor R2 to provide a protected 12V. The Vc terminal is connected to the voltage divider circuit.

3. A low voltage power supply circuit for a top stream machine system according to claim 2, characterized in that: The second switching device includes an NPN transistor Q2, and the voltage divider circuit includes voltage divider resistors R11 and R13; The Vc terminal of the PNP transistor Q1 is connected to ground after being connected in series with voltage divider resistors R11 and R13. The Vb and Ve terminals of the NPN transistor Q2 are connected in parallel with the voltage divider resistor R13, with the Ve terminal grounded. The Vc terminal is connected in series with R9 and then connected to the enable terminal of U1.

4. A low voltage power supply circuit for a top stream machine system according to claim 3, characterized in that: A capacitor C10 is connected in parallel across the voltage divider resistor R13.

5. A low voltage power supply circuit for a top stream machine system according to claim 4, characterized in that: It includes a second protection circuit, which includes a protection resistor R14 and a capacitor C11, which are connected in series between the enable terminal of U1 and ground.

6. A power supply protection chip for a top flow machine system, characterized by: Includes the low-voltage power supply circuit of the top flow machine system as described in any one of claims 1-5.

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