An uninterrupted power supply circuit for an industrial endoscope and an industrial endoscope

Abstract

The utility model relates to a kind of uninterruptible power supply circuit and industrial endoscope for industrial endoscope, and it is related to integrated circuit field.The first stage charge-discharge circuit one end is connected with external power supply, and the other end is connected with second stage charge-discharge circuit, main battery respectively.The second stage charge-discharge circuit is connected with backup battery, wide voltage input power supply conversion circuit respectively.The uninterruptible power supply circuit of the utility model, for traditional dual power supply switching circuit, creatively proposes a kind of brand-new hardware uninterruptible power supply circuit, realizes main battery, backup battery and external power supply seamless switching (actual measurement delay <100ns), without schottky diode voltage drop.Support industrial endoscope when replacing main battery continuous work ≥30 minutes, and realize the intelligent charge-discharge management and protection of main, backup battery, adapt to harsh industrial environment.The entire circuit output voltage fluctuation is small, switching delay is low, charge-discharge efficiency is high, entire circuit efficiency actual measurement is greater than >93%, and power supply efficiency is up to 97.5%.

Description

Technical Field

[0001] This utility model relates to the field of integrated circuits, and more particularly to an uninterruptible power supply circuit for industrial endoscopes and an industrial endoscope. Background Technology

[0002] Most industrial endoscopes currently rely on a single battery for power. Replacing the battery requires shutting down the system, interrupting the testing process and affecting real-time data acquisition and the safety of the inspected equipment. Some industrial endoscopes use a pure capacitor backup power solution, but its capacity is limited and cannot support long-term switching operations (usually only a few seconds).

[0003] A few industrial endoscopes use dual power supply switching circuits to solve the above problems. However, this traditional dual power supply switching circuit has problems such as large voltage fluctuations, high switching delay (>50ms), and low charging and discharging efficiency (<85%). At the same time, it lacks perfect input and output protection and is susceptible to damage from surges or short circuits. Summary of the Invention

[0004] In view of the above problems, the present invention aims to provide an uninterruptible power supply circuit for an industrial endoscope and an industrial endoscope that overcomes or at least partially solves the above problems.

[0005] In a first aspect, this utility model embodiment provides a power supply circuit for an industrial endoscope, comprising: a first-stage charging and discharging circuit, a second-stage charging and discharging circuit, a main battery, a backup battery, and a wide-voltage input power conversion circuit. One end of the first-stage charging and discharging circuit is connected to an external power source, and the other end is connected to the second-stage charging and discharging circuit and the main battery, respectively. The second-stage charging and discharging circuit is connected to the backup battery and the wide-voltage input power conversion circuit, respectively. The first-stage charging and discharging circuit is configured to charge the main battery with electrical energy provided by the external power source, and to provide electrical energy to the second-stage charging and discharging circuit. The second-stage charging and discharging circuit is configured to charge the backup battery with electrical energy provided by the external power source or the main battery, and to provide electrical energy to the wide-voltage input power conversion circuit. The main battery is configured to provide power to the second-stage charging and discharging circuit when the external power source cannot provide power. The backup battery is configured to provide power to the wide-voltage input power conversion circuit when neither the external power source nor the main battery can provide power. The wide-voltage input power conversion circuit is configured to generate a stable voltage based on the electrical energy and provide it to the industrial endoscope.

[0006] Optionally, the first-stage charging and discharging circuit includes: The second resettable fuse has one end connected to the external power supply, and the other end connected to the first end of the transient voltage suppressor diode, the first end of the fifth resistor, the source of the second MOSFET, the VIN pin of the control chip, the first end of the second resistor, and the source of the first MOSFET, respectively. The second terminal of the transient voltage suppressor diode is connected to the second terminal of the fifth resistor, the gate of the second MOSFET, and the first terminal of the seventh resistor, respectively. The second terminal of the second resistor is connected to the first terminal of the sixth resistor and the drain of the second MOSFET, respectively. The second end of the seventh resistor is connected to the drain of the third MOSFET, the source of the third MOSFET is grounded, and the gate is connected to the output of the inverter. The input of the inverter is grounded through a resistor and connected to the MPPT pin of the control chip. The second terminal of the sixth resistor is connected to the first terminals of the eighth and ninth resistors respectively, and the second terminal of the ninth resistor is grounded. The second end of the eighth resistor is grounded through a capacitor and connected to the UVCLFB pin of the control chip; The gate of the first MOSFET is connected to the INFET pin of the control chip, and the drain is connected to the first end of the first resistor and the first end of the third resistor, respectively. The second end of the third resistor is connected to the CLP pin of the control chip, and is connected to the CLN pin of the control chip and the second end of the fourth resistor respectively through a capacitor; The second end of the first resistor is connected to the first end of the fourth resistor and the SYS pin of the control chip, respectively, and the power supplied by the external power supply is output after passing through a filter capacitor bank. The second terminal of the fourth resistor is also connected to the SYS pin via a capacitor; The SYSMS pin of the control chip is connected to the source of the fourth MOSFET and the drain of the fifth MOSFET through a capacitor. The source of the fourth MOSFET also outputs the power supplied by the main battery after passing through a filter capacitor bank; the source of the fourth MOSFET is connected to the OUTFET pin of the control chip; the drain of the fourth MOSFET is connected to the second terminal of the inductor and the first terminal of the sensing resistor, respectively. The first end of the inductor is connected to the source of the fifth MOSFET, the drain of the sixth MOSFET, and the SW pin of the control chip, respectively; the gate of the fifth MOSFET is connected to the TG pin of the control chip. The second end of the inductor is also connected to the CSP pin of the control chip, and through a capacitor it is connected to the CSPMS pin of the control chip, and through another capacitor it is connected to the CSN pin of the control chip. The gate of the sixth MOSFET is connected to the BG pin of the control chip, and the source of the sixth MOSFET is grounded. The second end of the sensing resistor is connected to the CSN pin, and also to the second ends of the first resettable fuse and the third resettable fuse, respectively; The first end of the first self-resetting fuse is short-circuited with the first end of the third self-resetting fuse and then connected to the main battery.

[0007] Optionally, the second-stage charging and discharging circuit includes a set of the same components as the first-stage charging and discharging circuit, and the connection relationships between the components are also the same; The second-stage charging and discharging circuit is configured to receive electrical energy supplied by the external power source after the second terminal of the first resistor passes through a filter capacitor bank, or to receive electrical energy supplied by the main battery after the source of the fourth MOS transistor passes through a filter capacitor bank. The second-stage charging and discharging circuit is configured to provide the received electrical energy to the wide-voltage input power conversion circuit while also charging the backup battery.

[0008] Optionally, the wide-voltage input power conversion circuit includes: a power chip, an input filter capacitor bank, and an output filter capacitor bank; The VIN1~VIN10 pins, SVIN1, SVIN2 pins and IIN pin of the power chip are connected in parallel with the input filter capacitor group. The power chip is configured so that the power supplied by the external power supply, or the power supplied by the main battery, or the power supplied by the backup battery is filtered by the input filter capacitor group and then enters the VIN1~VIN10 pins, SVIN1, SVIN2 pins and IIN pin. The power chip is configured such that the incoming electrical energy is converted to a different voltage level by its internal BOOST-BUCK circuit and then output through the VOUT1~VOUT18 pins and the IOUT pin. After being filtered by the output filter capacitor bank, a low-ripple and stable 12V output voltage is obtained and provided to the industrial endoscope.

[0009] Optionally, the MODE pin in the power chip is connected to the LL pin through a resistor to configure the power chip in discontinuous operation mode.

[0010] Optionally, the control chip is configured to send a first control signal to the gate of the first MOSFET via the INFET pin to control the first MOSFET to turn on when the voltage corresponding to the VIN pin is not less than the voltage of the main battery; and to send a second control signal to the gate of the first MOSFET via the INFET pin to control the first MOSFET to turn off when the voltage corresponding to the VIN pin is less than the voltage of the main battery; and simultaneously send a third control signal to the gate of the fourth MOSFET via the OUTFET pin to control the fourth MOSFET to turn on. The control chip is configured such that, after the fourth MOSFET is turned on, if the voltage corresponding to the VIN pin is not less than the voltage of the main battery, a fourth control signal is sent to the gate of the fourth MOSFET through the OUTFET pin to turn off the fourth MOSFET, and a fifth control signal is sent to the gate of the first MOSFET through the INFET pin to turn on the first MOSFET.

[0011] Optionally, the control chip is configured to have a switching delay time of 22ns from the first MOS transistor being turned off to the fourth MOS transistor being turned on, or from the fourth MOS transistor being turned off to the first MOS transistor being turned on.

[0012] Optionally, the control chip is configured to use the CSP pin, the CSN pin, and the detection resistor to obtain the charging and discharging voltage, charging and discharging current, battery ESR, and battery coulomb count state of the main battery. The control chip is configured to dynamically adjust the charging current and charging voltage of the main battery under trickle, constant current, and constant voltage states based on the acquired charging voltage and charging current, through PWM duty cycle adjustment of the TG pin and the BG pin, and switching control of the SW pin.

[0013] Optionally, the control chip is model LTC4015; The voltage range provided by the external power source is 12.6V~30V; The main battery is model 3S3P, with a voltage range of 10.8V~12.6V; The backup battery is model 2S1P, with a voltage range of 7.2V~8.4V; The first MOSFET, the fifth MOSFET, and the sixth MOSFET are all N-MOSFETs, model IPT015N10N5, with an on-resistance Rdson=45mΩ; the fourth MOSFET is a P-MOSFET, model SQJ479EP-T1_GE3, with an on-resistance Rdson=67mΩ. The inductor is an alloy integral molded power inductor, model number FXL1040-1R5-M, with parameters of 1.5uH ±20% 8.5A; The resistance of the detection resistor is 4 mΩ; The parameters of the second resettable fuse are 7A / 30V, and the parameters of the first resettable fuse and the third resettable fuse are both 20A / 30V. The power chip is model LTM8055IY, and its input voltage range is 5V~36V.

[0014] Secondly, embodiments of the present invention provide an industrial endoscope, the industrial endoscope including an uninterruptible power supply circuit for the industrial endoscope as described in any of the first aspects.

[0015] The uninterruptible power supply circuit for industrial endoscopes of this utility model includes: a first-stage charging and discharging circuit, a second-stage charging and discharging circuit, a main battery, a backup battery, and a wide-voltage input power conversion circuit; one end of the first-stage charging and discharging circuit is connected to an external power source, and the other end is connected to the second-stage charging and discharging circuit and the main battery, respectively.

[0016] The second-stage charging and discharging circuit is connected to the backup battery and the wide-voltage input power conversion circuit, respectively. The first-stage charging and discharging circuit is configured to charge the main battery using power supplied from an external power source and to provide power to the second-stage charging and discharging circuit. The second-stage charging and discharging circuit is configured to charge the backup battery using power supplied from an external power source and to provide power to the wide-voltage input power conversion circuit.

[0017] The main battery is configured to provide power to the second-stage charging and discharging circuit when the external power source is unable to provide power; the backup battery is configured to provide power to the wide-voltage input power conversion circuit when neither the external power source nor the main battery can provide power; the wide-voltage input power conversion circuit is configured to generate a stable voltage based on the power source and provide it to the industrial endoscope.

[0018] This invention presents a novel hardware-based uninterruptible power supply circuit that creatively addresses the limitations of traditional dual-power switching circuits. Based on the LTC4015 chip and its peripheral circuits, it achieves seamless switching between the main battery, backup battery, and external power supply (measured delay <100ns) through an ideal diode seamless switching circuit, a Buck charging circuit, and Boost-Buck power conversion technology, with no Schottky diode voltage drop.

[0019] It can support industrial endoscopes to work continuously for ≥30 minutes (measured at a load current of 2A / 12V) when the main battery is replaced, and realizes intelligent charging and discharging management and protection of the main and backup batteries, making it suitable for harsh industrial environments. The entire circuit has small output voltage fluctuations, low switching delays, and high charging and discharging efficiency. The measured efficiency of the entire circuit is greater than 93%, and the power supply efficiency reaches up to 97.5%, making it highly practical. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a modular schematic diagram of an uninterruptible power supply circuit for an industrial endoscope according to an embodiment of this utility model. Figure 2This is a schematic diagram of the first-stage charging and discharging circuit exemplified in the embodiments of this utility model; Figure 3 This is a schematic diagram of the structure of the second-stage charging and discharging circuit exemplified in the embodiments of this utility model; Figure 4 This is a schematic diagram of the structure of a wide-voltage input power conversion circuit exemplified in the embodiments of this utility model. Detailed Implementation

[0021] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] The uninterruptible power supply circuit for industrial endoscopes of this invention includes: a first-stage charging and discharging circuit, a second-stage charging and discharging circuit, a main battery, a backup battery, and a wide-voltage input power conversion circuit; see reference. Figure 1 The modular schematic diagram shows that one end of the first-stage charging / discharging circuit is connected to an external power source, and the other end is connected to the second-stage charging / discharging circuit and the main battery, respectively. The first-stage charging / discharging circuit and the main battery can be housed in the battery compartment for easy replacement and maintenance.

[0023] The second-stage charging / discharging circuit is connected to the backup battery and the wide-voltage input power conversion circuit respectively. These three components can be integrated into the industrial endoscope. Alternatively, they can be mounted separately on a PCB board, facilitating separation from the endoscope for easier replacement and maintenance. If integrated with the endoscope, replacing or maintaining any of these three components requires opening the endoscope, which is relatively cumbersome.

[0024] In the above structure, the first-stage charging and discharging circuit is configured to charge the main battery and provide power to the second-stage charging and discharging circuit using electrical energy supplied by an external power source; the second-stage charging and discharging circuit is configured to charge the backup battery and provide power to the wide-voltage input power conversion circuit using electrical energy supplied by an external power source or the main battery; the main battery is configured to provide power to the second-stage charging and discharging circuit when the external power source cannot provide power; the backup battery is configured to provide power to the wide-voltage input power conversion circuit when neither the external power source nor the main battery can provide power; the wide-voltage input power conversion circuit is configured to generate a stable voltage based on electrical energy and provide it to the industrial endoscope.

[0025] To better understand the circuit structure of the uninterruptible power supply circuit described above, refer to... Figure 2 The diagram shown is a schematic of the first-stage charging and discharging circuit. Figure 2 The control chip U1 is illustrated using the LTC4015 chip as an example.

[0026] The second resettable fuse F2, one end is connected to the external power supply ( Figure 2 J2 represents the socket for external power supply. The external power supply can be plugged into J2. DCIN represents the DC input of the external power supply. The other end is connected to the first end of transient voltage suppressor diode D1, the first end of fifth resistor R5, the source of second MOSFET Q2, the VIN pin of control chip U1, the first end of second resistor R2, and the source of first MOSFET Q1, respectively. Figure 2 The capacitors C1~C5 and C10 form a filter capacitor group to filter the power supplied by the external power source. DCIN_P indicates that there is also a fuse between the external power source and this filter capacitor group, which is not shown for the sake of simplicity in the diagram.

[0027] The second terminal of transient voltage suppressor diode D1 is connected to the second terminal of the fifth resistor R5, the gate of the second MOSFET Q2, and the first terminal of the seventh resistor R7, respectively. The second terminal of the second resistor R2 is connected to the first terminal of the sixth resistor R6 and the drain of the second MOSFET Q2, respectively.

[0028] The second terminal of the seventh resistor R7 is connected to the drain of the third MOSFET Q3. The source of the third MOSFET Q3 is grounded, and its gate is connected to the output of inverter U2. The input of inverter U2 is grounded through a resistor R20 and connected to the MPPT pin of control chip U1. The structure composed of the fifth resistor R5, the second MOSFET Q2, the seventh resistor R7, the third MOSFET Q3, and inverter U2 is designed to prevent excessively high external power supply voltage from impacting the circuit structure. In the event of excessively high voltage, a grounding loop is formed, ensuring that the power supplied by the external power supply flows to ground and does not affect other circuit structures.

[0029] The second terminal of the sixth resistor R6 is connected to the first terminals of the eighth and ninth resistors R8 and R9, respectively. The second terminal of the ninth resistor R9 is grounded. The second terminal of the eighth resistor R8 is grounded through a capacitor C20 and connected to the UVCLFB pin of the control chip U1.

[0030] The gate of the first MOSFET Q1 is connected to the INFET pin of the control chip U1, and the drain is connected to the first end of the first resistor R1 and the first end of the third resistor R3 respectively. The second end of the third resistor R3 is connected to the CLP pin of the control chip U1, and is connected to the CLN pin of the control chip U1 and the second end of the fourth resistor R4 respectively through a capacitor C19.

[0031] The second terminal of the first resistor R1 is connected to the first terminal of the fourth resistor R4 and the SYS pin of the control chip U1, respectively, and then connected through a filter capacitor bank ( Figure 2 The capacitors C6~C9 in the middle section output the electrical energy provided by the external power supply; Figure 2 In the example, VDD_POWER represents the output electrical energy.

[0032] The second end of the fourth resistor R4 is also connected to the SYS pin through a capacitor C21; the SYSMS pin of the control chip U1 is connected to the source of the fourth MOSFET Q4 and the drain of the fifth MOSFET Q5 through a capacitor C22.

[0033] The source of the fourth MOSFET Q4 is also connected to a filter capacitor bank ( Figure 2 The main battery provides power after the capacitors C15~C18 are connected; the source of the fourth MOSFET Q4 is connected to the OUTFET pin of the control chip U1; the drain of the fourth MOSFET Q4 is connected to the second terminal of the inductor L1 and the first terminal of the sensing resistor R22 respectively.

[0034] The first end of inductor L1 is connected to the source of the fifth MOSFET Q5, the drain of the sixth MOSFET Q6, and the SW pin of the control chip U1, respectively; the gate of the fifth MOSFET Q5 is connected to the TG pin of the control chip U1; the second end of inductor L1 is also connected to the CSP pin of the control chip U1, and is connected to the CSPMS pin of the control chip U1 through a capacitor C28, and to the CSN pin of the control chip U1 through another capacitor C29.

[0035] The gate of the sixth MOSFET Q6 is connected to the BG pin of the control chip U1, and the source of the sixth MOSFET Q6 is grounded; the second terminal of the sensing resistor R22 is connected to the CSN pin, and also to the second terminals of the first resettable fuse F1 and the third resettable fuse F3 respectively; the first terminal of the first resettable fuse F1 and the first terminal of the third resettable fuse F3 are shorted and then connected to the main battery ( Figure 2 J6 represents the socket for the main battery. The main battery can be connected by inserting it into J6.

[0036] The DC power input from the external power supply at socket J2 passes through the first MOSFET Q1 and the first resistor R1 to power the subsequent load. Simultaneously, the power supplied by the external power supply forms a synchronous buck circuit through the fifth MOSFET Q5, the sixth MOSFET Q6, inductor L1, and sensing resistor R22 to charge the main battery (e.g., a high-capacity lithium battery) connected to socket J6. When the external power supply is removed, the main battery discharges to the load through sensing resistor R22 and the fourth MOSFET Q4. The first MOSFET Q1 and the fourth MOSFET Q4, acting as an ideal ORING diode circuit, exhibit lower voltage drop, lower leakage current, and lower losses compared to conventional Schottky diodes.

[0037] The voltage divided by the second resistor R2, the sixth resistor R6, and the ninth resistor R9 from the external power supply is sent to the UVCLFB pin of the control chip U1 via the eighth resistor R8 to detect the input voltage. The voltage across the first resistor R1 is sampled and sent to the CLP and CLN pins of the control chip U1 to detect the discharge current. The voltage across the single end of the detection resistor R22 is sent to the BATSENS pin of the control chip U1 to detect the charging voltage; the voltage across the detection resistor R22 is sent to the CSP and CSN pins of the control chip U1 to detect the charging current. The main battery charging voltage and main battery charging current can be adjusted using the detection resistor R22.

[0038] In other words, the control chip U1 is configured to use the CSP pin, CSN pin, and sensing resistor R22 to obtain the charging and discharging voltage, charging and discharging current, battery ESR, and battery coulomb count status of the main battery. Based on the obtained charging voltage and charging current, the control chip U1 is configured to dynamically adjust the charging current and charging voltage of the main battery under trickle, constant current, and constant voltage states through PWM duty cycle adjustment of the TG pin and BG pin, and switching control of the SW pin.

[0039] The second resettable fuse F2 and the transient voltage suppressor diode D1 constitute the input protection circuit for the external power supply, protecting against power input overvoltage, overcurrent, short circuit, and electrostatic surge. The first resettable fuse F1 and the third resettable fuse F3 constitute the main battery input protection circuit.

[0040] For the other pins of the control chip U1, those skilled in the art can understand the functions of its peripheral circuits by referring to their pin labels. For example, the SCL and SDA pins are connected to the master device (such as an ORIN NANO controller, since the control chip U1 is considered a slave device) via the I²C bus, sending real-time battery voltage, current, temperature, and chip status (such as error flags). Simultaneously, the master device can dynamically adjust the charging current, voltage threshold, and operating mode. The CELL0, CELL1, CELL2, CHEM1, and CHEM2 pins, along with external resistors, constitute the filtering peripheral circuitry of the control chip U1 itself. Other pins will not be described in detail.

[0041] In this embodiment, the second-stage charging and discharging circuit includes the same set of components as the first-stage charging and discharging circuit, and the connection relationships between the components are also the same. The difference from the first charging and discharging circuit is that the second-stage charging and discharging circuit is configured to receive either the electrical energy supplied by an external power source output from the second terminal of the first resistor R1 through a filter capacitor bank, or the electrical energy supplied by the main battery output from the source of the fourth MOSFET Q4 through a filter capacitor bank; that is, the second-stage charging and discharging circuit receives... Figure 2 The second difference is that the second-stage charging and discharging circuit is configured to use the received electrical energy to power the wide-voltage input power conversion circuit while also charging the backup battery.

[0042] To better understand the structure of the second-stage charging and discharging circuit described above, refer to... Figure 3 The schematic diagram of the second-stage charging and discharging circuit shown is as follows. Figure 3 Zhongyu Figure 2 The same parts will not be discussed in detail. Figure 3 The control chip is U16, which is equivalent to Figure 2 The control chip U1 is used. The fourth self-resetting fuse F4 serves as the input protection for the second-stage charging and discharging circuit. Functionally, in addition to protecting the input of the second-stage charging and discharging circuit, it also serves as the output protection for the first-stage charging and discharging circuit.

[0043] Diode D43 is equivalent to Figure 2 Transient voltage suppressor diode D1, MOSFET Q27 is equivalent to Figure 2 The second MOSFET Q2; MOSFET Q26 is equivalent to Figure 2 The first MOSFET is Q1; MOSFETs Q29, Q30, and Q31 are equivalent to Figure 2 The fourth MOSFET is Q4, the fifth MOSFET is Q5, and the sixth MOSFET is Q6; socket J16 is equivalent to Figure 2 The middle socket J6 is connected to the backup battery, not the main battery. The remaining components and their connections are understood by those skilled in the art. Figure 2 The explanation is readily available through simple reasoning and will not be elaborated upon here.

[0044] The power input from VDD_POWER passes through MOSFET Q26 and resistor R88 to power the subsequent load (which is then filtered by the filter capacitor bank C261~C264 before being output). Figure 3The output is represented by Vjunc. Simultaneously, the power supplied by VDD_POWER forms a synchronous buck circuit through MOSFETs Q30 and Q31, inductor L2, and resistor R233 to charge the backup battery (e.g., a small-capacity lithium battery) connected to socket J16. When VDD_POWER runs out of power, the backup battery discharges to the load through resistor R233 and MOSFET Q29. MOSFETs Q26 and Q29 act as ideal ORING diodes, exhibiting lower voltage drop, lower leakage current, and lower losses compared to conventional Schottky diodes.

[0045] Resistors R89, R217, and R220 divide the voltage supplied by VDD_POWER, and the voltage is then sent to the UVCLFB pin of control chip U6 via resistor R219 to detect the input voltage. The voltage across resistor R88 is sampled and sent to the CLP and CLN pins of control chip U16 to detect the discharge current. The voltage across resistor R233 is sent to the BATSENS pin of control chip U16 to detect the charging voltage, and the voltage across resistor R233 is sent to the CSP and CSN pins of control chip U16 to detect the charging current. The backup battery charging voltage and charging current can be adjusted via resistor R233.

[0046] In other words, the control chip U16 is configured to use the CSP pin, CSN pin, and resistor R233 to obtain the charging and discharging voltage, charging and discharging current, battery ESR, and battery coulomb count status of the backup battery. Based on the obtained charging voltage and charging current, the control chip U16 is configured to dynamically adjust the charging current and charging voltage of the backup battery under trickle, constant current, and constant voltage states through PWM duty cycle adjustment of the TG pin and BG pin, and switching control of the SW pin.

[0047] The fourth resettable fuse F4 and diode D43 constitute the input protection circuit for VDD_POWER, protecting against power input overvoltage, overcurrent, short circuit, and electrostatic surge. The fifth resettable fuse F5 and the sixth resettable fuse F6 constitute the backup battery input protection circuit.

[0048] When the external power source or main battery is removed (e.g., when the battery box is replaced), the backup battery discharges to the load through R233 and MOSFET Q29, thereby achieving uninterrupted power supply to the industrial endoscope.

[0049] In the embodiments of this application, the wide-voltage input power conversion circuit includes: a power supply chip, an input filter capacitor bank, and an output filter capacitor bank; see reference. Figure 4The schematic diagram of the wide-voltage input power conversion circuit shown illustrates the structure of the VIN1~VIN10 pins, SVIN1, SVIN2 pins, and IIN pin of the power chip U24A, as well as the input filter capacitor bank. Figure 4 The capacitors C220~C224 are connected in parallel. The power chip U24A is configured to provide power from an external power source, the main battery, or the backup battery. That is, the power input through Vjunc is filtered by the input filter capacitor group and then enters the VIN1~VIN10 pins, SVIN1, SVIN2 pins, and IIN pin.

[0050] The power chip U24A is configured so that the incoming electrical energy is converted into voltage levels by its internal BOOST-BUCK circuit (usually composed of four MOSFETs) and then output through pins VOUT1~VOUT18 and the IOUT pin, and then through the output filter capacitor bank ( Figure 4 After filtering with capacitors C67~C71, C68, and C69, a low-ripple and stable 12V is obtained. Figure 4 The VDD_12V output voltage is supplied to the industrial endoscope.

[0051] In addition, the MODE pin in the power chip U24A is connected to the LL pin through a resistor R366, which configures the power chip U24A to operate in discontinuous mode and can prevent reverse current backflow.

[0052] In the embodiments of this application, the discharge control logic of the first-stage charging and discharging circuit and the second-stage charging and discharging circuit is the same. Taking the first-stage charging and discharging circuit as an example: based on the ideal diode "combining" PowerPath architecture, seamless switching between external power supply and main battery to load is realized.

[0053] The control chip U1 is configured to send a first control signal to the gate of the first MOSFET Q1 via the INFET pin when the voltage corresponding to the VIN pin is not less than the voltage of the main battery, thereby turning on the first MOSFET Q1; and to send a second control signal to the gate of the first MOSFET Q1 via the INFET pin when the voltage corresponding to the VIN pin is less than the voltage of the main battery, thereby turning off the first MOSFET. Simultaneously, it sends a third control signal to the gate of the fourth MOSFET Q4 via the OUTFET pin, thereby turning on the fourth MOSFET. In other words, when an external power supply is connected, the voltage provided by the external power supply (VIN≥12.6V) triggers the gate drive signal of Q1, prioritizing switching to external power supply; when the external power supply is removed and the main battery supplies power (VCSP: 10.8V~12.6V), the gate drive signal of Q4 is triggered, switching to main battery power supply.

[0054] The control chip U1 is configured such that after the fourth MOSFET Q4 is turned on, if the voltage corresponding to the VIN pin is not less than the main battery voltage, it sends a fourth control signal to the gate of the fourth MOSFET Q4 via the OUTFET pin to turn off the fourth MOSFET Q4. Simultaneously, it sends a fifth control signal to the gate of the first MOSFET Q1 via the INFET pin to turn on the first MOSFET Q1. That is, when both of these conditions are met, and the external power supply voltage VIN ≥ the main battery voltage VCSP, the external power supply is automatically selected. The control chip U1 is configured with a switching delay time of 22ns from the first MOSFET Q1 being turned off to the fourth MOSFET Q4 being turned on, or from the fourth MOSFET Q4 being turned off to the first MOSFET Q1 being turned on.

[0055] For charging the main battery: Based on the two MOSFETs Q5 and Q6 and the inductor L1 in the charging circuit, the external power supply charges the main battery. Based on the sensing resistor R22, the control chip U1 obtains the charging voltage and charging current, and through the PWM duty cycle adjustment of the TG and BG pins and the switching control of the SW pin, the charging current and charging voltage are dynamically adjusted in trickle, constant current and constant voltage states.

[0056] The second-stage charging and discharging circuit operates on the same principle as the first-stage circuit, except that the power supply input (VDD_POWER) comes from... Figure 2 The circuit's output, i.e., the energy source, comes from an external power supply or the main battery; the charging target is the backup battery connected to J16; when the external power supply and the main battery are removed (e.g., when the battery box is replaced), the backup battery discharges to the load through resistor R233 and MOSFET Q29, thereby achieving uninterrupted power supply to the industrial endoscope.

[0057] In the embodiments of this application, the preferred choice is: The control chip is model LTC4015; the voltage range of the external power supply is 12.6V~30V; the main battery is model 3S3P with a voltage range of 10.8V~12.6V; the backup battery is model 2S1P with a voltage range of 7.2V~8.4V.

[0058] The first, fifth, and sixth MOSFETs are all N-MOSFETs, model IPT015N10N5, with an on-resistance Rdson=45mΩ; the fourth MOSFET is a P-MOSFET, model SQJ479EP-T1_GE3, with an on-resistance Rdson=67mΩ.

[0059] The inductor is a one-piece alloy power inductor, model FXL1040-1R5-M, with parameters of 1.5uH ±20% 8.5A; the sensing resistor has a resistance of 4 mΩ; the second resettable fuse has parameters of 7A / 30V, and the first and third resettable fuses both have parameters of 20A / 30V; the power supply chip is model LTM8055IY, with an input voltage range of 5V~36V. In the wide-voltage input power conversion circuit, the parallel electrolytic capacitors at the input and output terminals have parameters of 150μF / 25V, 68μF / 25V, 47μF / 25V, and 22μF / 25V respectively. The output ripple is ≤50mV across the entire load range (0-6A), meeting the peak power and noise requirements of the endoscope. The power supply output accuracy is 1%, and the power efficiency reaches a maximum of 97.5%.

[0060] Based on the above-described uninterruptible power supply circuit for industrial endoscopes, this utility model embodiment also proposes an industrial endoscope, which includes the above-described uninterruptible power supply circuit for industrial endoscopes.

[0061] In summary, the uninterruptible power supply circuit for industrial endoscopes of this utility model includes: a first-stage charging and discharging circuit, a second-stage charging and discharging circuit, a main battery, a backup battery, and a wide-voltage input power conversion circuit; one end of the first-stage charging and discharging circuit is connected to an external power source, and the other end is connected to the second-stage charging and discharging circuit and the main battery, respectively.

[0062] The second-stage charging and discharging circuit is connected to the backup battery and the wide-voltage input power conversion circuit, respectively. The first-stage charging and discharging circuit is configured to charge the main battery using power supplied from an external power source and to provide power to the second-stage charging and discharging circuit. The second-stage charging and discharging circuit is configured to charge the backup battery using power supplied from an external power source and to provide power to the wide-voltage input power conversion circuit.

[0063] The main battery is configured to provide power to the second-stage charging and discharging circuit when the external power source is unable to provide power; the backup battery is configured to provide power to the wide-voltage input power conversion circuit when neither the external power source nor the main battery can provide power; the wide-voltage input power conversion circuit is configured to generate a stable voltage based on the power source and provide it to the industrial endoscope.

[0064] This invention presents a novel hardware-based uninterruptible power supply circuit that creatively addresses the limitations of traditional dual-power switching circuits. Based on the LTC4015 chip and its peripheral circuits, it achieves seamless switching between the main battery, backup battery, and external power supply (measured delay <100ns) through an ideal diode seamless switching circuit, a Buck charging circuit, and Boost-Buck power conversion technology. It eliminates Schottky diode voltage drop and achieves Oring circuit voltage drop <1mV.

[0065] It can support industrial endoscopes to operate continuously for ≥30 minutes (measured at a load current of 2A / 12V) while the main battery is being replaced, and it achieves intelligent charging and discharging management and protection for both the main and backup batteries. Only a single type of LTC4015 chip is needed to manage charging and output voltage, simplifying circuit complexity and adapting to harsh industrial environments. The entire circuit exhibits low output voltage fluctuation, low switching delay, and high charging and discharging efficiency. Actual measurements show an overall circuit efficiency greater than 93%, with a maximum power efficiency of 97.5%, demonstrating excellent practicality.

[0066] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0067] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0068] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims. All of these forms are within the protection scope of this application.

Claims

1. An uninterruptible power supply circuit for industrial endoscopes, characterized in that, include: The circuit consists of a first-stage charging and discharging circuit, a second-stage charging and discharging circuit, a main battery, a backup battery, and a wide-voltage input power conversion circuit. One end of the first-stage charging and discharging circuit is connected to an external power source, and the other end is connected to the second-stage charging and discharging circuit and the main battery, respectively. The second-stage charging and discharging circuit is connected to the backup battery and the wide-voltage input power conversion circuit, respectively. The first-stage charging and discharging circuit is configured to charge the main battery with electrical energy provided by the external power source, and to provide electrical energy to the second-stage charging and discharging circuit. The second-stage charging and discharging circuit is configured to charge the backup battery with electrical energy provided by the external power source or the main battery, and to provide electrical energy to the wide-voltage input power conversion circuit. The main battery is configured to provide power to the second-stage charging and discharging circuit when the external power source cannot provide power. The backup battery is configured to provide power to the wide-voltage input power conversion circuit when neither the external power source nor the main battery can provide power. The wide-voltage input power conversion circuit is configured to generate a stable voltage based on the electrical energy and provide it to the industrial endoscope.

2. The uninterruptible power supply circuit according to claim 1, characterized in that, The first-stage charging and discharging circuit includes: The second resettable fuse has one end connected to the external power supply, and the other end connected to the first end of the transient voltage suppressor diode, the first end of the fifth resistor, the source of the second MOSFET, the VIN pin of the control chip, the first end of the second resistor, and the source of the first MOSFET, respectively. The second terminal of the transient voltage suppressor diode is connected to the second terminal of the fifth resistor, the gate of the second MOSFET, and the first terminal of the seventh resistor, respectively. The second terminal of the second resistor is connected to the first terminal of the sixth resistor and the drain of the second MOSFET, respectively. The second end of the seventh resistor is connected to the drain of the third MOSFET, the source of the third MOSFET is grounded, and the gate is connected to the output of the inverter. The input of the inverter is grounded through a resistor and connected to the MPPT pin of the control chip. The second terminal of the sixth resistor is connected to the first terminals of the eighth and ninth resistors respectively, and the second terminal of the ninth resistor is grounded. The second end of the eighth resistor is grounded through a capacitor and connected to the UVCLFB pin of the control chip; The gate of the first MOSFET is connected to the INFET pin of the control chip, and the drain is connected to the first end of the first resistor and the first end of the third resistor, respectively. The second end of the third resistor is connected to the CLP pin of the control chip, and is connected to the CLN pin of the control chip and the second end of the fourth resistor respectively through a capacitor; The second end of the first resistor is connected to the first end of the fourth resistor and the SYS pin of the control chip, respectively, and the power supplied by the external power supply is output after passing through a filter capacitor bank. The second terminal of the fourth resistor is also connected to the SYS pin via a capacitor; The SYSMS pin of the control chip is connected to the source of the fourth MOSFET and the drain of the fifth MOSFET through a capacitor. The source of the fourth MOSFET also outputs the power supplied by the main battery after passing through a filter capacitor bank; the source of the fourth MOSFET is connected to the OUTFET pin of the control chip; the drain of the fourth MOSFET is connected to the second terminal of the inductor and the first terminal of the sensing resistor, respectively. The first end of the inductor is connected to the source of the fifth MOSFET, the drain of the sixth MOSFET, and the SW pin of the control chip, respectively; the gate of the fifth MOSFET is connected to the TG pin of the control chip. The second end of the inductor is also connected to the CSP pin of the control chip, and through a capacitor it is connected to the CSPMS pin of the control chip, and through another capacitor it is connected to the CSN pin of the control chip. The gate of the sixth MOSFET is connected to the BG pin of the control chip, and the source of the sixth MOSFET is grounded. The second end of the sensing resistor is connected to the CSN pin, and also to the second ends of the first resettable fuse and the third resettable fuse, respectively; The first end of the first self-resetting fuse is short-circuited with the first end of the third self-resetting fuse and then connected to the main battery.

3. The uninterruptible power supply circuit according to claim 2, characterized in that, The second-stage charging and discharging circuit includes a set of the same components as the first-stage charging and discharging circuit, and the connection relationships between the components are also the same. The second-stage charging and discharging circuit is configured to receive electrical energy supplied by the external power source after the second terminal of the first resistor passes through a filter capacitor bank, or to receive electrical energy supplied by the main battery after the source of the fourth MOS transistor passes through a filter capacitor bank. The second-stage charging and discharging circuit is configured to provide the received electrical energy to the wide-voltage input power conversion circuit while also charging the backup battery.

4. The uninterruptible power supply circuit according to claim 3, characterized in that, The wide-voltage input power conversion circuit includes: a power chip, an input filter capacitor bank, and an output filter capacitor bank; The VIN1~VIN10 pins, SVIN1, SVIN2 pins and IIN pin of the power chip are connected in parallel with the input filter capacitor group. The power chip is configured so that the power supplied by the external power supply, or the power supplied by the main battery, or the power supplied by the backup battery is filtered by the input filter capacitor group and then enters the VIN1~VIN10 pins, SVIN1, SVIN2 pins and IIN pin. The power chip is configured such that the incoming electrical energy is converted to a different voltage level by its internal BOOST-BUCK circuit and then output through the VOUT1~VOUT18 pins and the IOUT pin. After being filtered by the output filter capacitor bank, a low-ripple and stable 12V output voltage is obtained and provided to the industrial endoscope.

5. The uninterruptible power supply circuit according to claim 4, characterized in that, The MODE pin in the power chip is connected to the LL pin through a resistor, which configures the power chip to operate in a discontinuous mode.

6. The uninterruptible power supply circuit according to claim 2, characterized in that, The control chip is configured to send a first control signal to the gate of the first MOSFET via the INFET pin to control the first MOSFET to turn on when the voltage corresponding to the VIN pin is not less than the voltage of the main battery; and to send a second control signal to the gate of the first MOSFET via the INFET pin to control the first MOSFET to turn off when the voltage corresponding to the VIN pin is less than the voltage of the main battery; and to send a third control signal to the gate of the fourth MOSFET via the OUTFET pin to control the fourth MOSFET to turn on. The control chip is configured such that, after the fourth MOSFET is turned on, if the voltage corresponding to the VIN pin is not less than the voltage of the main battery, a fourth control signal is sent to the gate of the fourth MOSFET through the OUTFET pin to turn off the fourth MOSFET, and a fifth control signal is sent to the gate of the first MOSFET through the INFET pin to turn on the first MOSFET.

7. The uninterruptible power supply circuit according to claim 6, characterized in that, The control chip is configured to have a switching delay time of 22ns from the first MOS transistor being turned off to the fourth MOS transistor being turned on, or from the fourth MOS transistor being turned off to the first MOS transistor being turned on.

8. The uninterruptible power supply circuit according to claim 2, characterized in that, The control chip is configured to use the CSP pin, the CSN pin, and the detection resistor to obtain the charging and discharging voltage, charging and discharging current, battery ESR, and battery coulomb count state of the main battery. The control chip is configured to dynamically adjust the charging current and charging voltage of the main battery under trickle, constant current, and constant voltage states based on the acquired charging voltage and charging current, through PWM duty cycle adjustment of the TG pin and the BG pin, and switching control of the SW pin.

9. The uninterruptible power supply circuit according to claim 4, characterized in that, include: The control chip is model LTC4015; The voltage range provided by the external power source is 12.6V~30V; The main battery is model 3S3P, with a voltage range of 10.8V~12.6V; The backup battery is model 2S1P, with a voltage range of 7.2V~8.4V; The first MOSFET, the fifth MOSFET, and the sixth MOSFET are all N-MOSFETs, model IPT015N10N5, with an on-resistance Rdson=45mΩ; the fourth MOSFET is a P-MOSFET, model SQJ479EP-T1_GE3, with an on-resistance Rdson=67mΩ. The inductor is an alloy integral molded power inductor, model number FXL1040-1R5-M, with parameters of 1.5uH ±20% 8.5A; The resistance of the detection resistor is 4 mΩ; The parameters of the second resettable fuse are 7A / 30V, and the parameters of the first resettable fuse and the third resettable fuse are both 20A / 30V. The power chip is model LTM8055IY, and its input voltage range is 5V~36V.

10. An industrial endoscope, characterized in that, The industrial endoscope includes an uninterruptible power supply circuit for an industrial endoscope as described in any one of claims 1-9.

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