Watchdog control circuit and charging management terminal

Abstract

The utility model discloses a watchdog control circuit and a charging management terminal, a pin 1 of a watchdog chip U4 is connected with a VCC through a resistor R34, a pin 2 of the watchdog chip U4 is grounded, two ends of a capacitor C5 are respectively connected with the pin 1 and the pin 2 of the watchdog chip U4, a pin 3 of the watchdog chip U4 is grounded through a resistor R1, two ends of a power-on switch S2 are respectively connected with the VCC and the pin 3 of the watchdog chip U4, and two ends of the power-on switch S2 are respectively connected with the VCC and the pin 3 of the watchdog chip U4. A pin 4 of the watchdog chip U4 is connected with the VCC through a resistor R46 and a resistor R11 in sequence, a pin 5 of the watchdog chip U4 is connected to one end of a resistor R41, and a pin 6 of the watchdog chip U4 is connected to the VCC through a resistor R213; the watchdog control circuit further comprises a dog feeding sub-circuit, and the dog feeding sub-circuit is connected to a pin 4 of the watchdog chip U4 and operably transmits a dog feeding signal to the watchdog chip U4. The watchdog control circuit and the charging management terminal provided by the utility model can still work normally in the programming process of the main control chip, and do not send a low-level reset signal.

Description

Technical Field

[0001] The utility model relates to a watchdog control circuit and a charging management terminal. Background Art

[0002] With the modularization of new energy supporting products, rail-type intelligent charging management terminal products are widely used due to their small size, small hardware design space, reliable and simple circuits, and few components.

[0003] The rail-mounted intelligent charging management terminal has complex functions and requires high real-time performance, necessitating an operating system solution. To ensure product reliability and self-recovery capabilities, an external watchdog circuit is typically added, connected to the main chip via a feed signal (RUN) and a reset signal (RST). The main chip feeds the watchdog circuit (a square wave with a certain period) to maintain normal operation, and the reset signal remains high. If the main chip program experiences an anomaly, feeding the watchdog stops. If the watchdog circuit does not receive a feed signal within a timing cycle, the watchdog reset signal outputs a low level, forcing a system reset.

[0004] The watchdog timer period is typically set via peripheral hardware. The duration is determined based on the system's power-up time to ensure the system does not reset during startup. It's typically designed to be around 50 seconds.

[0005] However, chips with operating systems require programming kernel drivers and application layer programs, a time-consuming process that typically takes 2 to 3 minutes. The watchdog timer begins counting after power is applied. If the program is not programmed by the end of a cycle, the system cannot provide a feed signal, causing the watchdog to output a reset signal, causing programming failure.

[0006] The existing solution is to increase the reset period of the watchdog timer. However, if the reset period is set too long during the production process, it means that the test time of the production process will be extended, thereby increasing production costs and reducing efficiency. Utility Model Content

[0007] The utility model provides a watchdog control circuit and a charging management terminal to solve the above-mentioned technical problems, specifically adopting the following technical solutions:

[0008] A watchdog control circuit, comprising: a watchdog chip U4, a resistor R34, a capacitor C5, a resistor R1, a power-on switch S2, a resistor R213, a resistor R41, a resistor R46 and a resistor R11;

[0009] Pin 1 of the watchdog chip U4 is connected to VCC through the resistor R34, pin 2 of the watchdog chip U4 is grounded, two ends of the capacitor C5 are respectively connected to pin 1 and pin 2 of the watchdog chip U4, pin 3 of the watchdog chip U4 is grounded through the resistor R1, two ends of the power-on switch S2 are respectively connected to VCC and pin 3 of the watchdog chip U4, pin 4 of the watchdog chip U4 is sequentially connected to VCC through the resistor R46 and the resistor R11, pin 5 of the watchdog chip U4 is connected to one end of the resistor R41, and pin 6 of the watchdog chip U4 is connected to VCC through the resistor R213;

[0010] The watchdog control circuit further includes a dog feeding sub-circuit, which is connected to pin 4 of the watchdog chip U4 and is operable to transmit a dog feeding signal to the watchdog chip U4.

[0011] Furthermore, the dog feeding sub-circuit is connected between the resistor R46 and the resistor R11.

[0012] Furthermore, the dog feeding sub-circuit includes an RTC clock chip U900 and a shorting switch S1 , one end of the shorting switch S1 is connected between the resistor R46 and the resistor R11 , and the other end is connected to the 10 port of the RTC clock chip U900 .

[0013] Furthermore, the dog feeding sub-circuit includes an RTC clock chip U900 and a relay, one end of the relay is connected between the resistor R46 and the resistor R11, and the other end is connected to the 10 port of the RTC clock chip U900, and the control end of the relay is connected to an external signal control device.

[0014] Furthermore, the relay is a photorelay.

[0015] Furthermore, the RTC clock chip U900 is 8025T, and its 10 ports send 1Hz pulse output signals.

[0016] Furthermore, the resistance range of the resistor R1 is 500Ω to 180KΩ.

[0017] Furthermore, the watchdog chip U4 is SGM821.

[0018] Furthermore, VCC is 3.3V.

[0019] A guide rail type intelligent charging management terminal includes a main control chip. The guide rail type intelligent charging management terminal also includes the aforementioned watchdog control circuit, and the watchdog control circuit is connected to the main control chip.

[0020] The utility model is beneficial in that the watchdog control circuit and charging management terminal provided can still work normally during the programming process of the main control chip without sending a low-level reset signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 The utility model is a schematic diagram of a watchdog control circuit. DETAILED DESCRIPTION

[0023] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0024] This application discloses a watchdog control circuit for use in a DIN-rail intelligent charging management terminal for managing electric vehicle charging. The DIN-rail intelligent charging management terminal includes a main control chip and a watchdog control circuit connected to the main control chip. The watchdog circuit is connected to the main control chip via a feed signal (RUN) and a reset signal (RST).

[0025] The rail-mounted intelligent charging management terminal has complex functions and requires high real-time performance, requiring an operating system solution. The main control chip with the operating system requires the kernel driver and application layer programs to be burned, which is a time-consuming process. The watchdog control circuit of this application can still operate normally during the main control chip burning process without sending a low-level reset signal.

[0026] like Figure 1 As shown, the watchdog control circuit disclosed in the present application includes: a watchdog chip U4, a resistor R34, a capacitor C5, a resistor R1, a power-on switch S2, a resistor R213, a resistor R41, a resistor R46 and a resistor R11.

[0027] Pin 1 of the watchdog chip U4 is connected to VCC through a resistor R34. In this application, VCC is 3.3 V. In this application, the watchdog chip U4 is SGM821.

[0028] Pin 2 of watchdog chip U4 is grounded. Capacitor C5 is connected to pins 1 and 2 of watchdog chip U4, respectively. Pin 3 of watchdog chip U4 is grounded via resistor R1, which has a resistance range of 500Ω to 180kΩ. Power-on switch S2 is connected to VCC and pin 3 of watchdog chip U4, respectively. Pin 4 of watchdog chip U4 is connected to VCC via resistors R46 and R11, respectively. Pin 5 of watchdog chip U4 is connected to one end of resistor R41. Pin 6 of watchdog chip U4 is connected to VCC via resistor R213.

[0029] In this application, the main control chip is connected to pins 4, 5, and 6 of the watchdog chip U4. The main control chip sends a dog feeding signal to pin 4 of the watchdog chip U4, and pin 6 of the watchdog chip U4 transmits a high level to the main control chip.

[0030] The watchdog control circuit further includes a dog feeding sub-circuit, which is connected to pin 4 of the watchdog chip U4 and is operable to transmit a dog feeding signal to the watchdog chip U4.

[0031] In an embodiment of the present application, the dog feeding sub-circuit is connected between resistor R46 and resistor R11. Specifically, the dog feeding sub-circuit includes an RTC clock chip U900 and a shorting switch S1. One end of the shorting switch S1 is connected between resistor R46 and resistor R11, and the other end is connected to port 10 of the RTC clock chip U900.

[0032] In the embodiment of the present application, the RTC clock chip U900 is 8025T, and its port 10 sends a 1Hz pulse output signal. When programming, short S1, the 1Hz pulse replaces the main control chip's dog feeding signal and feeds the watchdog chip, achieving the purpose of preventing the output of the reset signal.

[0033] As another optional embodiment, the dog feeding subcircuit includes an RTC clock chip U900 and a relay. One end of the relay is connected between resistors R46 and R11, and the other end is connected to port 10 of the RTC clock chip U900. The control end of the relay is connected to an external signal control device. Specifically, the relay is a photorelay. In this way, the shorting subcircuit can be easily controlled by an external control signal.

[0034] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A watchdog control circuit, characterized in that: Includes: watchdog chip U4, resistor R34, capacitor C5, resistor R1, power-on switch S2, resistor R213, resistor R41, resistor R46 and resistor R11; Pin 1 of the watchdog chip U4 is connected to VCC through the resistor R34, pin 2 of the watchdog chip U4 is grounded, two ends of the capacitor C5 are respectively connected to pin 1 and pin 2 of the watchdog chip U4, pin 3 of the watchdog chip U4 is grounded through the resistor R1, two ends of the power-on switch S2 are respectively connected to VCC and pin 3 of the watchdog chip U4, pin 4 of the watchdog chip U4 is sequentially connected to VCC through the resistor R46 and the resistor R11, pin 5 of the watchdog chip U4 is connected to one end of the resistor R41, and pin 6 of the watchdog chip U4 is connected to VCC through the resistor R213; The watchdog control circuit further includes a dog feeding sub-circuit, which is connected to pin 4 of the watchdog chip U4 and is operable to transmit a dog feeding signal to the watchdog chip U4.

2. The watchdog control circuit according to claim 1, wherein: The dog feeding sub-circuit is connected between the resistor R46 and the resistor R11.

3. The watchdog control circuit according to claim 2, wherein: The dog feeding sub-circuit includes an RTC clock chip U900 and a shorting switch S1 , one end of the shorting switch S1 is connected between the resistor R46 and the resistor R11 , and the other end is connected to the 10 port of the RTC clock chip U900 .

4. The watchdog control circuit according to claim 2, wherein: The dog feeding sub-circuit includes an RTC clock chip U900 and a relay, one end of the relay is connected between the resistor R46 and the resistor R11, and the other end is connected to the 10 port of the RTC clock chip U900, and the control end of the relay is connected to an external signal control device.

5. The watchdog control circuit according to claim 4, characterized in that: The relay is a photorelay.

6. The watchdog control circuit according to any one of claims 3 to 5, characterized in that: The RTC clock chip U900 is 8025T, and its 10 ports send 1Hz pulse output signals.

7. The watchdog control circuit according to claim 1, wherein: The resistance of the resistor R1 ranges from 500Ω to 180KΩ.

8. The watchdog control circuit according to claim 1, wherein: The watchdog chip U4 is SGM821.

9. The watchdog control circuit according to claim 1, wherein: VCC is 3.3V.

10. A charging management terminal, comprising a main control chip, characterized in that: The charging management terminal further includes a watchdog control circuit as described in any one of claims 1 to 9, and the watchdog control circuit is connected to the main control chip.

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