Novel battery charging time-delay circuit of load control terminal

Abstract

The utility model discloses a novel battery charging delay circuit of a load control terminal, and belongs to the technical field of charging delay. Comprising a delay starting part, the delay starting part comprises a first resistor, and the first end of the first resistor is connected with a first power supply voltage; the base electrode of the first triode is connected with the second end of the first resistor, and the emitter electrode of the first triode is grounded; the first end of the first capacitor is connected with the second end of the first resistor, and the second end of the first capacitor is connected with the emitter of the first triode; the step-down conversion part is connected with the delay starting part and the standby battery; and a battery charging management unit connected to the backup battery. The beneficial effects of the technical scheme are that the time-delay battery charging circuit is adopted, the battery is charged by trickle current after being charged to a certain electric quantity, the burden on the power supply is reduced, the phenomenon of overload protection of the power supply is avoided, the power and the volume of the switching power supply are reduced, the stability is strong, the cost is low, and the production and the maintenance are easier.

Description

Technical Field

[0001] The utility model relates to the technical field of charging delay, in particular to a battery charging delay circuit for a new type of negative control terminal. Background Art

[0002] In power negative control terminal devices, backup batteries are required to perform functions such as power-off monitoring, reporting power-off events, and normal shutdown of the system after the external power supply of the device is cut off, which are necessary functions for the stable operation of the terminal. Due to the overall power consumption requirements of the terminal system, the battery needs to have a capacity of 5000Mah@3.7V and a current output capacity of at least 2A, and the terminal power supply needs to automatically charge the backup battery. Therefore, a charging current of 1A is designed. However, during the prototype test, it is found that if the external power supply of the terminal is cut off and the backup battery is enabled, it will discharge. So when the external power supply is powered on again, the battery is basically in a state of insufficient power and needs to be charged. But when the system starts, the CPU host, the external 230M radio station, and the 5G communication module are all powered on and working at the same time. The load impact of the whole machine on the ACDC power supply switching power supply can reach more than twice the average power consumption of the device. If the load capacity of the switching power supply is designed to be 1.5 times the average power consumption, then this startup current impact may cause the power supply to overload and protect, resulting in startup failure.

[0003] In the prior art, generally, the problem of power supply overload is solved by increasing the load capacity of the switching power supply and increasing the power of the power supply. However, increasing the load capacity of the power supply reduces the power supply protection caused by the startup impact. In addition, increasing the power of the switching power supply will increase the product cost, increase the volume of the power supply, increase the standby power consumption, reduce the power efficiency, and cause the volume of the device to increase, thus increasing the costs of production, installation, transportation, and operation and maintenance. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a battery charging delay circuit for a new type of negative control terminal to solve the above technical problems;

[0005] A battery charging delay circuit for a new type of negative control terminal includes,

[0006] A delay start part, and the delay start part includes,

[0007] A first resistor, the first end of which is connected to a first supply voltage;

[0008] A first triode, the base of which is connected to the second end of the first resistor, and the emitter of which is grounded;

[0009] A first capacitor, the first end of which is connected to the second end of the first resistor, and the second end of which is connected to the emitter of the first triode;

[0010] A step-down conversion unit, connected to the delay start unit and the backup battery;

[0011] A battery charging management unit, connected to the backup battery.

[0012] Preferably, the delay start unit further includes,

[0013] A second resistor, the first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is connected to the emitter of the first triode;

[0014] A third resistor, the first end of the third resistor is connected to the first power supply voltage;

[0015] A first MOS transistor, the gate of the first MOS transistor is connected to the second end of the third resistor, the source of the first MOS transistor is connected to the first power supply voltage, and the drain of the first MOS transistor is connected to the step-down conversion unit;

[0016] A fourth resistor, the first end of the fourth resistor is connected to the second end of the third resistor, and the second end of the fourth resistor is connected to the collector of the first triode.

[0017] Preferably, the step-down conversion unit includes,

[0018] A step-down converter, the input voltage pin of the step-down converter is connected to the delay start unit, the ground pin of the step-down converter is grounded, the feedback pin of the step-down converter is connected to the charging voltage, and the switch pin of the step-down converter is grounded;

[0019] A second capacitor, the first end of the second capacitor is connected to the delay start unit;

[0020] A third capacitor, the first end of the third capacitor is connected to the input voltage pin of the step-down converter, the second end of the third capacitor is connected to the second end of the second capacitor, and the second end of the third capacitor is also connected to the ground pin of the step-down converter;

[0021] A first inductor, the first end of the first inductor is connected to the output voltage pin of the step-down converter, and the second end of the first inductor is connected to the charging voltage;

[0022] A first diode, the cathode of the first diode is connected to the first end of the first inductor, and the anode of the first diode is connected to the ground pin of the step-down converter;

[0023] A fourth capacitor, the first end of the fourth capacitor is connected to the second end of the first inductor, and the second end of the fourth capacitor is connected to the anode of the first diode;

[0024] A fifth capacitor, a first end of the fifth capacitor is connected to a first end of the fourth capacitor, and a second end of the fifth capacitor is connected to a second end of the fourth capacitor;

[0025] The first end of the fifth capacitor is also connected to the charging voltage.

[0026] Preferably, the buck conversion unit further includes,

[0027] A fifth resistor, a first end of the fifth resistor is connected to the charging voltage, and a second end of the fifth resistor is connected to a standby signal;

[0028] A sixth resistor, a first end of the sixth resistor is connected to the second end of the fifth resistor, and a second end of the sixth resistor is grounded;

[0029] A power point is provided between a feedback pin of the buck converter and the charging voltage.

[0030] Preferably, the battery charging management unit includes,

[0031] A boost converter, a second pin of the boost converter is grounded, and a first pin of the boost converter is connected to a second power supply voltage;

[0032] A sixth capacitor, a first end of the sixth capacitor is connected to the first pin of the boost converter;

[0033] A first touch switch, a first pin and a second pin of the first touch switch are connected to the first end of the sixth capacitor, and a fourth pin of the first touch switch is connected to the second end of the sixth capacitor;

[0034] A second diode, an anode of the second diode is connected to the second end of the sixth capacitor;

[0035] A ninth resistor, a first end of the ninth resistor is connected to the second power supply voltage;

[0036] A second MOS transistor, a gate of the second MOS transistor is connected to a second end of the ninth resistor, a source of the second MOS transistor is connected to the first end of the ninth resistor, and a drain of the second MOS transistor is connected to a third power supply voltage;

[0037] A tenth resistor, a first end of the tenth resistor is connected to the drain of the second MOS transistor;

[0038] An eleventh resistor, a first end of the eleventh resistor is connected to a second end of the tenth resistor, and a second end of the eleventh resistor is grounded.

[0039] Preferably, the battery charging management unit further includes,

[0040] A third diode, an anode of the third diode is connected to a terminal voltage, and a cathode of the third diode is connected to the cathode of the second diode;

[0041] A seventh resistor, a first end of the seventh resistor is connected to the cathode of the second diode;

[0042] A second triode, a base of the second triode is connected to a second end of the seventh resistor, and a collector of the second triode is connected to a second end of the ninth resistor.

[0043] Preferably, the battery charging management unit further includes,

[0044] An analog multiplexer, a ground pin of the analog multiplexer is grounded, and a power supply pin of the analog multiplexer is connected to the terminal voltage;

[0045] A fourth diode, a cathode of the fourth diode is connected to a timing signal, and an anode of the fourth diode is connected to an input pin of the analog multiplexer;

[0046] A twelfth resistor, a first end of the twelfth resistor is connected to the anode of the fourth diode, and a second end of the twelfth resistor is connected to the cathode of the fourth diode;

[0047] A second touch switch, a first pin and a second pin of the second touch switch are connected to an output pin of the analog multiplexer, and a third pin of the second touch switch is grounded;

[0048] A seventh capacitor, a first end of the seventh capacitor is connected to the second pin of the second touch switch, a second end of the seventh capacitor is connected to a fourth pin of the second touch switch, and the first end of the seventh capacitor is further connected to the base of the second triode;

[0049] A thirteenth resistor, a first end of the thirteenth resistor is connected to a fourth power supply voltage, and a second end of the thirteenth resistor is connected to a selection pin of the analog multiplexer;

[0050] A fourteenth resistor, a first end of the fourteenth resistor is connected to the second end of the thirteenth resistor, a second end of the fourteenth resistor is grounded, and the second end of the fourteenth resistor is further connected to an emitter of the second triode;

[0051] An eighth resistor, a first end of the eighth resistor is connected to the cathode of the third diode, and a second end of the eighth resistor is connected to the second end of the fourteenth resistor.

[0052] Preferably, the battery charging management unit further includes,

[0053] The eighth capacitor, with the first end of the eighth capacitor connected to the terminal voltage and the second end of the eighth capacitor grounded;

[0054] The battery disconnection point is provided between the output pin of the analog multiplexer and the second touch switch;

[0055] The voltage measurement point is provided between the tenth resistor and the eleventh resistor.

[0056] Preferably, the delay start part delays for 120 ms to charge the backup battery, and the charging voltage for the backup battery is 5V.

[0057] Preferably, the timing signal is output from the real-time clock 10 s after the external power is cut off.

[0058] The beneficial effects of the present utility model are as follows: By adopting a delay battery charging circuit, the battery is charged with trickle charging after being charged to a certain power, reducing the burden on the power supply, avoiding the phenomenon of power overload protection, reducing the power and volume of the switching power supply, having strong stability, low cost, and being more conducive to production and maintenance. Description of the Drawings

[0059] Figure 1 is the circuit diagram of the delay start part of the present utility model;

[0060] Figure 2 is the circuit diagram of the buck conversion part of the present utility model;

[0061] Figure 3 is the circuit connection diagram of the fifth resistor and the sixth resistor of the buck conversion part of the present utility model;

[0062] Figure 4 is the circuit diagram of the battery charging management part of the present utility model;

[0063] Figure 5 is the circuit connection diagram of the eighth capacitor of the battery charging management part of the present utility model;

[0064] Figure 6 is the connection schematic diagram of the battery charging delay circuit of the present utility model. Detailed Embodiments

[0065] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0066] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments may be combined with each other.

[0067] The present utility model will be further described below with reference to the accompanying drawings and specific embodiments, but it is not limited to the present utility model.

[0068] A battery charging delay circuit for a new type of negative control terminal, as Figures 1 to 6 shown, includes a delay start-up part 1, and the delay start-up part 1 includes

[0069] a first resistor R1, the first end of the first resistor R1 is connected to the first supply voltage +5V;

[0070] a first triode Q1, the base of the first triode Q1 is connected to the second end of the first resistor R1, and the emitter of the first triode Q1 is grounded;

[0071] a first capacitor C1, the first end of the first capacitor C1 is connected to the second end of the first resistor R1, and the second end of the first capacitor C1 is connected to the emitter of the first triode Q1;

[0072] a buck conversion part 2, connected to the delay start-up part 1 and the backup battery 3;

[0073] a battery charging management part 4, connected to the backup battery 3.

[0074] Specifically, the present utility model provides a battery charging delay circuit for a new type of negative control terminal. By adopting a delayed battery charging circuit, the battery is charged with a trickle charge when it is recharged to a certain amount of power, reducing the burden on the power supply, avoiding the phenomenon of power overload protection, reducing the power and volume of the switching power supply, having strong stability, low cost, and being more conducive to production and maintenance.

[0075] Further specifically, under the condition of a determined terminal housing, not only the main frequency, memory, and computing power of the CPU are increased, the original 7-inch dot matrix liquid crystal display screen is replaced with a 10.1-inch touch screen, and the original display screen with button operation and dot matrix display of letters and numbers is replaced with a graphical interface and touch operation; 5 expansion modules and a 5G communication module (power consumption > 5W) are installed in the original space, and the main circuit space of the new type of negative control terminal is severely compressed, and the overall power consumption of the whole machine must be additionally increased by 25W. Under this condition, in order to effectively reduce the power of the switching power supply and control the volume of the switching power supply module to the minimum. When powering on and starting up, it is necessary to avoid a large impact source on the power supply, and the delay target is at least more than 120 ms. After the CPU host completes startup and both the 5G and 230M modules are stably started, then charge the battery with a current of about 1A@5V.

[0076] In a preferred embodiment, the delay start-up part 1 further includes

[0077] The second resistor R2, the first end of the second resistor R2 is connected to the second end of the first resistor R1, and the second end of the second resistor R2 is connected to the emitter of the first triode Q1;

[0078] The third resistor R3, the first end of the third resistor R3 is connected to the first power supply voltage +12V;

[0079] The first MOS transistor Q2, the gate of the first MOS transistor Q2 is connected to the second end of the third resistor R3, the source of the first MOS transistor Q2 is connected to the first power supply voltage +12V, and the drain of the first MOS transistor Q2 is connected to the buck conversion unit 2;

[0080] The fourth resistor R4, the first end of the fourth resistor R4 is connected to the second end of the third resistor R3, and the second end of the fourth resistor R4 is connected to the collector of the first triode Q1.

[0081] Specifically, when the system is powered on, the third resistor R3 applies a +12V voltage to the gate of the first MOS transistor Q2. Due to the action of the fourth resistor R4 and the first triode Q1, the collector voltage of the first triode Q1 will affect the gate voltage of the first MOS transistor Q2, thereby controlling the on-state of the first MOS transistor Q2.

[0082] The first capacitor C1 is a polarized capacitor. By setting the first resistor R1 and the first capacitor C1, the time constant of the delay can be accurately controlled.

[0083] In a preferred embodiment, the buck conversion unit 2 includes,

[0084] The buck converter N1, the input voltage pin VIN of the buck converter N1 is connected to the delay start unit 1, the input voltage pin VIN of the buck converter N1 is connected to the input voltage +12VC of the delay start unit 1, the ground pin GND1 of the buck converter N1 is grounded, the feedback pin FB of the buck converter N1 is connected to the charging voltage +5VC, and the switch pin ON / OFF of the buck converter N1 is grounded;

[0085] The second capacitor C2, the first end of the second capacitor C2 is connected to the delay start unit 1, and the first end of the second capacitor C2 is connected to the input voltage +12VC of the delay start unit 1;

[0086] The third capacitor C3, the first end of the third capacitor C3 is connected to the input voltage pin VIN of the buck converter N1, the second end of the third capacitor C3 is connected to the second end of the second capacitor C2, and the second end of the third capacitor C3 is also connected to the ground pin GND1 of the buck converter N1;

[0087] The first inductor L1, the first end of the first inductor L1 is connected to the output voltage pin OUTPUT of the buck converter N1, and the second end of the first inductor L1 is connected to the charging voltage +5VC;

[0088] The first diode D1, the cathode of the first diode D1 is connected to the first end of the first inductor L1, and the anode of the first diode D1 is connected to the ground pin GND1 of the buck converter N1;

[0089] The fourth capacitor C4, the first end of the fourth capacitor C4 is connected to the second end of the first inductor L1, and the second end of the fourth capacitor C4 is connected to the anode of the first diode D1;

[0090] The fifth capacitor C5, the first end of the fifth capacitor C5 is connected to the first end of the fourth capacitor C4, and the second end of the fifth capacitor C5 is connected to the second end of the fourth capacitor C4;

[0091] The first end of the fifth capacitor C5 is also connected to the charging voltage +5VC;

[0092] The buck conversion unit 2 further includes,

[0093] The fifth resistor R5, the first end of the fifth resistor R5 is connected to the charging voltage +5VC, and the second end of the fifth resistor R5 is connected to the standby signal VOL_NPDN;

[0094] The sixth resistor R6, the first end of the sixth resistor R6 is connected to the second end of the fifth resistor R5, and the second end of the sixth resistor R6 is grounded;

[0095] The power supply point +5VC1 is provided between the feedback pin FB of the buck converter N1 and the charging voltage +5VC.

[0096] Specifically, when the terminal is powered on, the switch power supply outputs +12V, and this +12V is controlled by the first resistor R1 and the first capacitor C1 of the delay circuit. The collector potential of the first triode Q1 is charged to the control potential of 0.69V, turning on the collector and emitter of the first triode Q1, and sending +12V to the input end of the DCDC N1, thus generating +5VC for charging the battery.

[0097] More specifically, the feedback pin FB of the buck converter N1 is connected to the +5V charging voltage, ensuring the stability of the output voltage. Charging will only start when the input voltage and the feedback voltage of the buck converter N1 reach a stable state. The fourth capacitor C4 and the second capacitor C2 are polarized capacitors. The third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 provide a filtering function to reduce voltage fluctuations and improve power supply stability. The combination of the third capacitor C3, the fourth capacitor C4, and the first inductor L1 forms a low-pass filter, effectively reducing the ripple in the output voltage.

[0098] The first diode D1 is a zener diode. The first diode D1 prevents reverse current flow and protects the circuit from damage. The first inductor L1, the fourth capacitor C4, and the fifth capacitor C5 together form an appropriate energy storage and filtering network to support a stable current output.

[0099] The fifth resistor R5 and the sixth resistor R6 are set to determine the logic level of the standby signal and ensure that the buck converter starts under appropriate conditions.

[0100] In a preferred embodiment, the battery charging management unit 4 includes

[0101] A boost converter BAT. The second pin of the boost converter BAT is grounded, and the first pin of the boost converter BAT is connected to the second power supply voltage +VB4.2I;

[0102] A sixth capacitor C6. The first end of the sixth capacitor C6 is connected to the first pin of the boost converter BAT;

[0103] A first touch switch SW1. The first pin and the second pin of the first touch switch SW1 are connected to the first end of the sixth capacitor C6, and the fourth pin of the first touch switch SW1 is connected to the second end of the sixth capacitor C6;

[0104] A second diode D2. The anode of the second diode D2 is connected to the second end of the sixth capacitor C6;

[0105] A ninth resistor R9. The first end of the ninth resistor R9 is connected to the second power supply voltage +VB4.2I;

[0106] A second MOS transistor Q4. The gate of the second MOS transistor Q4 is connected to the second end of the ninth resistor R9, the source of the second MOS transistor Q4 is connected to the first end of the ninth resistor R9, and the drain of the second MOS transistor Q4 is connected to the third power supply voltage +VB4.2;

[0107] A tenth resistor R10. The first end of the tenth resistor R10 is connected to the drain of the second MOS transistor Q4;

[0108] An eleventh resistor R11. The first end of the eleventh resistor R11 is connected to the second end of the tenth resistor R10, and the second end of the eleventh resistor R11 is grounded;

[0109] The battery charging management unit 4 further includes

[0110] A third diode D3. The anode of the third diode D3 is connected to the terminal voltage +3.3V, and the cathode of the third diode D3 is connected to the cathode of the second diode D2;

[0111] A seventh resistor R7. The first end of the seventh resistor R7 is connected to the cathode of the second diode D2;

[0112] The second triode Q3, the base of the second triode Q3 is connected to the second end of the seventh resistor R7, and the collector of the second triode Q3 is connected to the second end of the ninth resistor R9;

[0113] The battery charging management unit 4 further includes

[0114] An analog multiplexer M, the ground pin GND2 of the analog multiplexer M is grounded, and the power supply pin VCC of the analog multiplexer M is connected to the terminal voltage +3.3V;

[0115] The fourth diode D4, the cathode of the fourth diode D4 is connected to the timing signal WKUP, and the anode of the fourth diode D4 is connected to the input pin B0 of the analog multiplexer M;

[0116] The twelfth resistor R12, the first end of the twelfth resistor R12 is connected to the anode of the fourth diode D4, and the second end of the twelfth resistor R12 is connected to the cathode of the fourth diode D4;

[0117] The second touch switch SW2, the first pin and the second pin of the second touch switch SW2 are connected to the output pin A of the analog multiplexer M, and the third pin of the second touch switch SW2 is grounded;

[0118] The seventh capacitor C7, the first end of the seventh capacitor C7 is connected to the second pin of the second touch switch SW2, the second end of the seventh capacitor C7 is connected to the fourth pin of the second touch switch SW2, and the first end of the seventh capacitor C7 is also connected to the base of the second triode Q3;

[0119] The thirteenth resistor R13, the first end of the thirteenth resistor R13 is connected to the fourth power supply voltage PV, and the second end of the thirteenth resistor R13 is connected to the selection pin Select of the analog multiplexer M;

[0120] The fourteenth resistor R14, the first end of the fourteenth resistor R14 is connected to the second end of the thirteenth resistor R13, the second end of the fourteenth resistor R14 is grounded, and the second end of the fourteenth resistor R14 is also connected to the emitter of the second triode Q3;

[0121] The eighth resistor R8, the first end of the eighth resistor R8 is connected to the cathode of the third diode D3, and the second end of the eighth resistor R8 is connected to the second end of the fourteenth resistor R14;

[0122] The battery charging management unit 4 further includes

[0123] The eighth capacitor C8, the first end of the eighth capacitor C8 is connected to the terminal voltage +3.3V, and the second end of the eighth capacitor C8 is grounded;

[0124] The battery disconnection point OFF_BAT is set between the output pin A of the analog multiplexer M and the second touch switch SW2;

[0125] The voltage measurement point +VB42Vol is set between the tenth resistor R10 and the eleventh resistor R11.

[0126] Specifically, when the terminal is powered on, the +3.3V of the terminal will automatically turn on the second MOS transistor Q4, enabling the battery to provide backup power to the terminal circuit; after external power failure, when the system detects a power failure event (simultaneously with the power failure, the backup battery 3 automatically powers the system), it will execute a power failure reporting event, set the RTC (Real-Time Clock) to output a timing signal (WKUP) after 10 seconds, and then execute system shutdown (to protect the memory). After 10 seconds, the RTC outputs a valid signal of WKUP, cutting off the second MOS transistor Q4 and closing the discharge circuit of the battery to save power. After external power is restored, the +3.3V of the terminal automatically turns on the second MOS transistor Q4, and the delay circuit will delay for 120ms for charging.

[0127] In this battery circuit switch control circuit, two small tactile switches SW1 and SW2 are also placed. Under the condition of external power failure, SW1 is used to manually turn on the battery switch circuit, and SW2 is used to manually turn off the battery switch circuit. These two small buttons are small in size and extremely low in cost, which can facilitate testers to turn on / off the backup battery at any time, and the operation is extremely convenient.

[0128] Further specifically, the boost converter BAT meets the requirements of battery charging. Its second pin is grounded, and its first pin is connected to the second power supply voltage. Through the configuration of the sixth capacitor C6 and the first touch switch SW1, the output voltage of the boost converter BAT is stabilized and filtered.

[0129] The second MOS transistor Q4 plays a role in charging control. Its gate is connected to the power supply voltage through the ninth resistor R9 to determine the switching state of charging. By dividing the voltage of the tenth resistor R10 and the eleventh resistor R11, the voltage change during the battery charging process can be monitored.

[0130] The voltage measurement point +VB42Vol is set between the tenth resistor R10 and the eleventh resistor R11 for real-time monitoring of the battery voltage. This monitoring point helps ensure that the battery charging voltage is within a safe range, thus preventing overcharging.

[0131] The second diode D2, the third diode D3, and the fourth diode D4 are set to ensure the directionality of the circuit and prevent reverse current flow, which can protect the circuit components and ensure the correct charging direction. The cathode of the second diode D2 is connected to the second end of the sixth capacitor C6 and is connected to the anode of the third diode D3 to form a stable voltage reference.

[0132] The first touch switch SW1 and the second touch switch SW2 are used for user input and control, helping to select different operation modes or settings. The connection method of the first touch switch SW1 and the second touch switch SW2, as well as their combination with capacitors and resistors, affects the response speed and stability of touch input.

[0133] In a preferred embodiment, the delay start unit 1 delays for 120 ms to charge the backup battery 3, and the charging voltage for the backup battery 3 is 5V.

[0134] Specifically, by setting a delay of 120 ms in the delay start unit 1, the circuit can avoid directly charging the backup battery 3 within a certain period after startup. This prevents the impact of transient current on the battery and reduces the instability during the battery charging process.

[0135] The charging voltage of the backup battery 3 is 5V to ensure charging efficiency and battery life. The selection of the charging voltage takes into account the electrochemical characteristics of the backup battery 3 to ensure that the battery will not overheat or overcharge during charging.

[0136] In the present utility model, the control circuit in the negative control terminal may adjust the charging strategy according to the load conditions. By adopting a delayed battery charging circuit, after the battery is recharged to the set power, it is charged by trickle charging to reduce the burden on the power supply, avoid the phenomenon of power supply overloading protection, reduce the power and volume of the switching power supply, with strong stability, low cost, and being more conducive to production and maintenance. The delayed start mechanism enables the negative control terminal to complete other necessary initialization operations, such as system stability detection, before the start of charging, thereby optimizing the battery charging process. It minimizes the constant voltage charging time after power-on. When the power supply is powered on and started, there will be no phenomenon of overloading protection, reducing the power and volume of the switching power supply, improving the stability of the system power supply, effectively reducing the cost, making the new negative control terminal have greater competitive advantages and better processability in spatial layout, and being more conducive to production and on-site maintenance.

[0137] In a preferred embodiment, the timing signal WKUP is output from the real-time clock after 10 s of external power failure.

[0138] Specifically, after power failure, the power outage process is quickly processed, and a 10-second-level timing cut-off backup power circuit is designed to avoid unnecessary excessive discharge, and it minimizes the constant voltage charging time after power-on.

[0139] The RTC module continues to work through the built-in battery when the power supply is powered off and can accurately track time. After the external power supply is powered off, the RTC ensures that the system can accurately output the WKUP signal after 10 s by maintaining its clock function. This ensures that the system has enough time to complete the initialization process or stability detection after the power supply is restored. It prevents the direct charging of the battery at the moment when the power supply is restored, thereby reducing the potential impact on the battery.

[0140] By setting the delay of the WKUP signal, the circuit can ensure that other parts of the system (such as the battery management system or the load circuit) are in a stable state before starting to charge after the power supply is restored. This avoids the influence of transient current after power restoration and improves the reliability of the system.

[0141] Considering the power-off and power-restoration situations, the circuit design involves voltage stability and protection circuits during power restoration to ensure that the charging process can proceed smoothly after the WKUP signal is output.

[0142] In summary, the present application provides a battery charging delay circuit for a new type of negative control terminal. By selecting a delay battery charging circuit, the large current is relatively constant compared to other modules. When the battery is recharged to a certain level, trickle charging is used, reducing the burden on the power supply. After power-off, the power-off process is quickly processed, and a 10-second-level timer is designed to cut off the backup power circuit to avoid unnecessary over-discharge. After power-on, the constant voltage charging time is minimized. There has never been an overload protection phenomenon during power-on startup, reducing the power and volume of the switching power supply, improving the stability of the system power supply, effectively reducing costs, giving the new type of negative control terminal a greater competitive advantage in spatial layout and better processability, and being more conducive to production and on-site maintenance.

[0143] The above are only the preferred embodiments of the present utility model, and do not limit the implementation manners and protection scope of the present utility model. For those skilled in the art, it should be realized that all equivalent replacements and obvious changes made by using the content of the specification and drawings of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A battery charging delay circuit for a new type of negative control terminal, characterized in that, including a delay start section (1), and the delay start section (1) includes a first resistor (R1), with the first end of the first resistor (R1) connected to a first supply voltage (+5V); a first triode (Q1), with the base of the first triode (Q1) connected to the second end of the first resistor (R1) and the emitter of the first triode (Q1) grounded; a first capacitor (C1), with the first end of the first capacitor (C1) connected to the second end of the first resistor (R1) and the second end of the first capacitor (C1) connected to the emitter of the first triode (Q1); a step-down conversion section (2), connected to the delay start section (1) and a backup battery (3); a battery charging management section (4), connected to the backup battery (3).

2. The battery charging delay circuit of the novel negative control terminal according to claim 1, characterized in that, The delay start section (1) further includes a second resistor (R2), with the first end of the second resistor (R2) connected to the second end of the first resistor (R1) and the second end of the second resistor (R2) connected to the emitter of the first triode (Q1); a third resistor (R3), with the first end of the third resistor (R3) connected to a first power supply voltage (+12V); a first MOS transistor (Q2), with the gate of the first MOS transistor (Q2) connected to the second end of the third resistor (R3), the source of the first MOS transistor (Q2) connected to the first power supply voltage (+12V), and the drain of the first MOS transistor (Q2) connected to the step-down conversion section (2); a fourth resistor (R4), with the first end of the fourth resistor (R4) connected to the second end of the third resistor (R3) and the second end of the fourth resistor (R4) connected to the collector of the first triode (Q1).

3. The battery charging delay circuit of the novel negative control terminal according to claim 1, characterized in that, The step-down conversion section (2) includes a step-down converter (N1), with the input voltage pin (VIN) of the step-down converter (N1) connected to the delay start section (1), the ground pin (GND1) of the step-down converter (N1) grounded, the feedback pin (FB) of the step-down converter (N1) connected to a charging voltage (+5VC), and the switch pin (ON / OFF) of the step-down converter (N1) grounded; a second capacitor (C2), with the first end of the second capacitor (C2) connected to the delay start section (1); a third capacitor (C3), with the first end of the third capacitor (C3) connected to the input voltage pin (VIN) of the step-down converter (N1), the second end of the third capacitor (C3) connected to the second end of the second capacitor (C2), and the second end of the third capacitor (C3) also connected to the ground pin (GND1) of the step-down converter (N1); a first inductor (L1), with the first end of the first inductor (L1) connected to the output voltage pin (OUTPUT) of the step-down converter (N1) and the second end of the first inductor (L1) connected to the charging voltage (+5VC); The first diode (D1), the cathode of the first diode (D1) is connected to the first end of the first inductor (L1), and the anode of the first diode (D1) is connected to the ground pin (GND1) of the buck converter (N1); The fourth capacitor (C4), the first end of the fourth capacitor (C4) is connected to the second end of the first inductor (L1), and the second end of the fourth capacitor (C4) is connected to the anode of the first diode (D1); The fifth capacitor (C5), the first end of the fifth capacitor (C5) is connected to the first end of the fourth capacitor (C4), and the second end of the fifth capacitor (C5) is connected to the second end of the fourth capacitor (C4); The first end of the fifth capacitor (C5) is also connected to the charging voltage (+5VC).

4. The battery charging delay circuit of the novel negative control terminal according to claim 3, characterized in that, The buck conversion unit (2) further includes, The fifth resistor (R5), the first end of the fifth resistor (R5) is connected to the charging voltage (+5VC), and the second end of the fifth resistor (R5) is connected to the standby signal (VOL_NPDN); The sixth resistor (R6), the first end of the sixth resistor (R6) is connected to the second end of the fifth resistor (R5), and the second end of the sixth resistor (R6) is grounded; The power supply point (+5VC1) is provided between the feedback pin (FB) of the buck converter (N1) and the charging voltage (+5VC).

5. The battery charging delay circuit of the novel negative control terminal according to claim 1, characterized in that, The battery charging management unit (4) includes, The boost converter (BAT), the second pin of the boost converter (BAT) is grounded, and the first pin of the boost converter (BAT) is connected to the second power supply voltage (+VB4.2I); The sixth capacitor (C6), the first end of the sixth capacitor (C6) is connected to the first pin of the boost converter (BAT); The first touch switch (SW1), the first and second pins of the first touch switch (SW1) are connected to the first end of the sixth capacitor (C6), and the fourth pin of the first touch switch (SW1) is connected to the second end of the sixth capacitor (C6); The second diode (D2), the anode of the second diode (D2) is connected to the second end of the sixth capacitor (C6); The ninth resistor (R9), the first end of the ninth resistor (R9) is connected to the second power supply voltage (+VB4.2I); The second MOS transistor (Q4), the gate of the second MOS transistor (Q4) is connected to the second end of the ninth resistor (R9), the source of the second MOS transistor (Q4) is connected to the first end of the ninth resistor (R9), and the drain of the second MOS transistor (Q4) is connected to the third power supply voltage (+VB4.2); The tenth resistor (R10), the first end of the tenth resistor (R10) is connected to the drain of the second MOS transistor (Q4); The eleventh resistor (R11), the first end of the eleventh resistor (R11) is connected to the second end of the tenth resistor (R10), and the second end of the eleventh resistor (R11) is grounded.

6. The battery charging delay circuit of the new negative control terminal according to claim 5, characterized in that The battery charging management unit (4) further includes, A third diode (D3), an anode of the third diode (D3) is connected to a terminal voltage (+3.3V), and a cathode of the third diode (D3) is connected to a cathode of the second diode (D2); A seventh resistor (R7), a first end of the seventh resistor (R7) is connected to the cathode of the second diode (D2); A second triode (Q3), a base of the second triode (Q3) is connected to a second end of the seventh resistor (R7), and a collector of the second triode (Q3) is connected to a second end of the ninth resistor (R9).

7. The battery charging delay circuit of the novel negative control terminal according to claim 6, characterized in that, The battery charging management unit (4) further includes, An analog multiplexer (M), a ground pin (GND2) of the analog multiplexer (M) is grounded, and a power supply pin (VCC) of the analog multiplexer (M) is connected to the terminal voltage (+3.3V); A fourth diode (D4), a cathode of the fourth diode (D4) is connected to a timing signal (WKUP), and an anode of the fourth diode (D4) is connected to an input pin (B0) of the analog multiplexer (M); A twelfth resistor (R12), a first end of the twelfth resistor (R12) is connected to the anode of the fourth diode (D4), and a second end of the twelfth resistor (R12) is connected to the cathode of the fourth diode (D4); A second touch switch (SW2), a first pin and a second pin of the second touch switch (SW2) are connected to an output pin (A) of the analog multiplexer (M), and a third pin of the second touch switch (SW2) is grounded; A seventh capacitor (C7), a first end of the seventh capacitor (C7) is connected to the second pin of the second touch switch (SW2), a second end of the seventh capacitor (C7) is connected to a fourth pin of the second touch switch (SW2), and the first end of the seventh capacitor (C7) is further connected to the base of the second triode (Q3); A thirteenth resistor (R13), a first end of the thirteenth resistor (R13) is connected to a fourth power supply voltage (PV), and a second end of the thirteenth resistor (R13) is connected to a selection pin (Select) of the analog multiplexer (M); A fourteenth resistor (R14), a first end of the fourteenth resistor (R14) is connected to the second end of the thirteenth resistor (R13), a second end of the fourteenth resistor (R14) is grounded, and the second end of the fourteenth resistor (R14) is further connected to an emitter of the second triode (Q3); An eighth resistor (R8), a first end of the eighth resistor (R8) is connected to the cathode of the third diode (D3), and a second end of the eighth resistor (R8) is connected to the second end of the fourteenth resistor (R14).

8. The battery charging delay circuit of the novel negative control terminal according to claim 7, characterized in that, The battery charging management unit (4) further includes, An eighth capacitor (C8), a first end of the eighth capacitor (C8) is connected to the terminal voltage (+3.3V), and a second end of the eighth capacitor (C8) is grounded; A battery disconnection point (OFF_BAT) is provided between the output pin (A) of the analog multiplexer (M) and the second touch switch (SW2); The voltage measurement point (+VB42Vol) is provided between the tenth resistor (R10) and the eleventh resistor (R11).

9. The battery charging delay circuit of the novel negative control terminal according to claim 1, wherein The delay start unit (1) delays for 120 ms to charge the backup battery (3), and the charging voltage for the backup battery (3) is 5V.

10. The battery charging delay circuit of the novel negative control terminal according to claim 7, characterized in that, The timing signal (WKUP) is output from the real-time clock after 10 s of external power failure.

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