On-site parameter power-down storage circuit without residual power

Abstract

The utility model discloses a residual-power-free field parameter power-down storage circuit, which comprises a power supply circuit, a power-down detection circuit, an MCU (Microprogrammed Control Unit), a data storage circuit and an electric quantity discharge circuit, the power supply circuit and the power-down detection circuit are respectively connected with an external power supply, and the power supply circuit comprises a two-stage DCDC (Direct Current to Direct Current) converter; the power leakage circuit comprises a capacitor E1, a diode D2, a diode D3, a current-limiting resistor R and an MOS tube Q1, the output end of the power failure detection circuit is connected with the signal input end of the MCU, the first signal output end of the MCU is connected with the data storage circuit, and the second signal output end of the MCU is connected with the control end of the MOS tube driver. The circuit of the scheme adopts a closed-loop control mode of power-down monitoring, field parameter storage and electric quantity discharge, so that rapid dissipation of residual power of a system after parameter storage is ensured, and rapid power-down not only ensures the safety of a working field of control equipment, but also ensures the working reliability of the control equipment after repeated power-on.

Description

Technical Field

[0001] The utility model relates to the technical field of electronics, in particular to a field parameter power-off storage circuit without residual power. Background Art

[0002] After the automation control device loses power, the parameter values ​​and status of the control device on site need to be written into the non-volatile memory so that the control device can continue to operate normally after being powered on again.

[0003] Usually, the power-off storage circuit adopts an open-loop control method of power-off detection + parameter storage. When the control device is detected to have lost power, the parameters of the control device are stored. This control method has residual power after the control device loses power and the residual power retention time is uncontrollable. The residual power after the control device loses power is likely to cause safety risks on site, and the control device is also prone to the risk of abnormal operation after repeated power-on. Utility Model Content

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the utility model is: how to provide a field parameter power-off storage circuit without residual power, which can store the parameters of the device after the control device is powered off, quickly dissipate the residual power after storage, and keep the residual power for a controllable time.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A field parameter power-off storage circuit without residual power, comprising a power supply circuit, a power-off detection circuit, an MCU, a data storage circuit and a power discharge circuit, wherein the power supply circuit and the power-off detection circuit are respectively connected to an external power supply, the power supply circuit comprises a primary DCDC converter and a secondary DCDC converter, the output end of the primary DCDC converter serves as a first voltage output end, the output end of the secondary DCDC converter serves as a second voltage output end, the power discharge circuit comprises a capacitor E1, a diode D2, a diode D3, a current limiting resistor R and a MOS tube Q1, the cathode of the diode D2 and the anode of the diode D3 are simultaneously connected to the first voltage output end, the anode of the diode D2 is connected to the The positive electrode of the capacitor E1 is connected to one end of the current-limiting resistor R, the negative electrode of the capacitor E1 is grounded, the other end of the current-limiting resistor R is connected to the cathode of the diode D3 and the drain of the MOS tube Q1 at the same time, the source of the MOS tube Q1 is grounded, and the gate of the MOS tube Q1 is connected to the MOS tube driver; the second voltage output end is respectively connected to the power-off detection circuit, the MCU, the data storage circuit and the MOS tube driver, the output end of the power-off detection circuit is connected to the signal input end of the MCU, the first signal output end of the MCU is connected to the data storage circuit, and the second signal output end of the MCU is connected to the control end of the MOS tube driver.

[0007] The working principle of this solution is: when the external power supply is normally supplied, the power supply circuit and the power-off detection circuit connected to the external power supply work normally. At this time, the output voltage of the first voltage output terminal charges the capacitor E1 after passing through the diode D3, and the output voltage of the second voltage output terminal is respectively supplied to the power-off detection circuit, MCU, data storage circuit and MOS tube driver.

[0008] When the external power supply is powered off, that is, when a power failure occurs, the capacitor E1 starts to discharge as a power supply, and the capacitor E1 supplies power to the first voltage output terminal of the power supply circuit through the diode D2, thereby causing the second voltage output terminal to output voltage normally, and the power failure detection circuit, MCU and data storage circuit keep working. At this time, after the external power supply is powered off, the output terminal signal of the power failure detection circuit will change (such as from a high-level signal to a low-level signal), and will be sent to the MCU, and the first signal output terminal of the MCU will output a signal to cause the data storage circuit to start data storage. When the storage is completed, the signal output from the second signal output terminal of the MCU to the MOS tube driver control terminal changes, causing the MOS tube driver to give a start signal to the gate of the MOS tube Q1, and the MOS tube Q1 is turned on. The residual electricity on the capacitor E1 is quickly discharged through the current limiting resistor R and the MOS tube Q1, and the entire circuit stops working.

[0009] Therefore, after the control device loses power, this solution uses the power on capacitor E1 to enable the memory to quickly store the parameters. On the other hand, after the parameter storage is completed, the discharge circuit formed by capacitor E1, current limiting resistor R and MOS tube Q1 is used to quickly dissipate the residual power on capacitor E1, thereby avoiding the safety risks that may be caused by the residual power. At the same time, by selecting the capacity of capacitor E1, the residual power retention time and the power-off speed can be controlled, so as to achieve the purpose of controllable residual power retention time.

[0010] Preferably, the power supply circuit further includes a diode D1, a cathode of the diode D1 is connected to the input end of the first-stage DCDC converter, and an anode of the diode D1 is used to be connected to an external power supply.

[0011] Preferably, the power-off detection circuit protects the photocoupler U2, the anode of the photocoupler U2 is connected to an external power supply, the cathode of the photocoupler U2 is grounded, the collector of the photocoupler U2 is connected to the second voltage output terminal, and the emitter of the photocoupler U2 is connected to the signal input terminal of the MCU through a resistor R11.

[0012] Preferably, the power-off detection circuit also includes a resistor R10, a resistor R11, a resistor R12 and a capacitor C2, one end of the resistor R10 is connected to an external power supply, the other end of the resistor R10 is connected to the anode end of the photoelectric coupler U2, one end of the resistor R12 and one end of the resistor R11 are both connected to the emitter of the photoelectric coupler U2, the other end of the resistor R12 is grounded, the other end of the resistor R11 is simultaneously connected to one end of the capacitor C2 and the signal input end of the MCU, and the other end of the capacitor C2 is grounded.

[0013] Preferably, the current limiting resistor R includes a resistor R3, a resistor R4, a resistor R5, a resistor R6 and a resistor R7 connected in series, and the resistor R3, the resistor R4, the resistor R5, the resistor R6 and the resistor R7 have the same resistance value.

[0014] Compared with the existing technology, the circuit of this scheme adopts a closed-loop control method of power-off monitoring, on-site parameter storage, and power discharge, thereby ensuring the rapid dissipation of the system's residual power after parameter storage. The rapid power-off not only ensures the safety of the control equipment working site, but also ensures the reliability of the control equipment after repeated power-on. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a circuit diagram of the power supply circuit in the field parameter power-off storage circuit without residual power of the utility model;

[0016] Figure 2 It is a circuit diagram of a power-off detection circuit in a field parameter power-off storage circuit without residual power of the utility model;

[0017] Figure 3 The circuit diagram of the MCU in the field parameter power-off storage circuit without residual power of the utility model;

[0018] Figure 4 A circuit diagram of a data storage circuit in a field parameter power-off storage circuit without residual power of the utility model;

[0019] Figure 5 The utility model is a circuit diagram of a power discharge circuit in a field parameter power-off storage circuit without residual power. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution of the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings of the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the described embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. Unless otherwise defined, the technical terms or scientific terms used herein should be the usual meanings understood by people with general skills in the field to which the utility model belongs.

[0021] The words "first", "second" and similar words used in the specification and claims of the utility model patent application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular form of "a", "an" or "the" and other similar words do not indicate a quantitative limitation, but indicate the existence of at least one. "Include" or "comprise" and other similar words mean that the elements or objects appearing before "include" or "comprise" cover the features, wholes, steps, operations, elements and / or components listed after "include" or "comprise", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] A field parameter power-off storage circuit without residual power comprises a power supply circuit, a power-off detection circuit, an MCU, a data storage circuit and an electric quantity discharge circuit.

[0023] As attached Figure 1As shown, in this embodiment, the power supply circuit inputs 24V voltage through the power supply plug, and outputs 5V and 3.3V power respectively through two power converters. Specifically, the power supply circuit is connected to the external 24V power supply through the power supply plug, and the power supply circuit includes a diode D1, a primary DCDC converter U5 and a secondary DCDC converter U6, the cathode of the diode D1 is connected to the input end of the primary DCDC converter U5, the anode of the diode D1 is used to connect to the external 24V power supply, the output end of the primary DCDC converter U5 is used as the first voltage output end, the output end of the secondary DCDC converter U6 is used as the second voltage output end, and the primary DCDC converter U5 adopts an isolation converter, and the output end of the primary DCDC converter U5 outputs a 5V voltage, and the output end of the secondary DCDC converter U6 outputs a 3.3V voltage.

[0024] As attached Figure 2 As shown, in this embodiment, the optocoupler element of the power-off detection circuit is connected to the MCU pin through a resistor, and the 24V power supply can be powered on and off corresponding to the pin signal change. Specifically, the power-off detection circuit is connected to the external 24V power supply, and the power-off detection circuit includes a photocoupler U2, a resistor R10, a resistor R11, a resistor R12 and a capacitor C2, one end of the resistor R10 is connected to the external 24V power supply, the other end of the resistor R10 is connected to the anode end of the photocoupler U2, the cathode of the photocoupler U2 is grounded, the collector of the photocoupler U2 is connected to the second voltage output end, that is, the collector of the photocoupler U2 is connected to a 3.3V voltage, one end of the resistor R12 and one end of the resistor R11 are both connected to the emitter of the photocoupler U2, the other end of the resistor R12 is grounded, the other end of the resistor R11 is simultaneously connected to one end of the capacitor C2 and the signal input end (KZ end) of the MCU, and the other end of the capacitor C2 is grounded.

[0025] As attached Figure 3 and attached Figure 4As shown, in this embodiment, the MCU and the data storage circuit both use a 3.3V operating voltage, and the MCU and the data storage circuit exchange data through data ports SCK and SDA. Specifically, the MCU has multiple interfaces, wherein the power supply terminal of the MCU is connected to the second voltage output terminal (i.e., the 3.3V voltage connection), the ground terminal of the MCU is grounded, the signal input terminal KZ of the MCU is connected to the emitter of the photocoupler U2 through the resistor R11, the first signal output terminal (SCK and SDA) of the MCU is connected to the data storage circuit, and the second signal output terminal (DYXF) of the MCU is connected to the MOS tube driver. The data storage circuit includes a memory U1, a capacitor C1, a resistor R1 and a resistor R2, wherein the power supply end of the memory U1 is connected to the second voltage output end (i.e., a 3.3V voltage connection), the SCL interface of the memory U1 is connected to the SCK interface of the MCU, the SDA interface of the memory U1 is connected to the SDA interface of the MCU, the memory U1 and the MCU exchange data through SCK and SDA, one end of the capacitor C1 is connected to the power supply end of the memory U1, the other end of the capacitor C1 is grounded, one end of the resistor R1 and one end of the resistor R2 are both connected to the 3.3V power supply, the other end of the resistor R1 is connected to the SCL interface of the memory U1, and the other end of the resistor R2 is connected to the SDA interface of the memory U1.

[0026] As attached Figure 5 As shown, in this embodiment, the power discharge circuit can charge the capacitor E1 when powered on, and the MCU can set the DYXF pin high after completing data storage when the power is off, and the MOS tube Q1 is turned on to start the discharge circuit. Specifically, the power discharge circuit includes capacitor E1, diode D2, diode D3, current limiting resistor R, MOS tube Q1, resistor R, resistor R9 and MOS tube driver, the current limiting resistor R includes resistor R3, resistor R4, resistor R5, resistor R6 and resistor R7 connected in series, and resistor R3, resistor R4, resistor R5, resistor R6 and resistor R7 have the same resistance value, the cathode of diode D2 and the anode of diode D3 are simultaneously connected to the first voltage output end (i.e., 5V voltage), the anode of diode D2 is connected to the positive electrode of capacitor E1 and one end of resistor R3, and the capacitor The negative electrode of E1 is grounded, the other end of the resistor R7 is connected to the cathode of the diode D3 and the drain of the MOS tube Q1 at the same time, the source of the MOS tube Q1 is grounded, the gate of the MOS tube Q1 is connected to the control end of the MOS tube driver U4 through the resistor R8, one end of the resistor R9 is connected to the gate of the MOS tube Q1, and the other end of the resistor R9 is connected to the source of the MOS tube Q1, the signal input end of the MOS tube driver U4 is connected to the second signal output end DYXF of the MCU, and the two power supply ends of the MOS tube driver U4 are also connected to the 5V power supply and the 3.3V power supply output ends respectively.

[0027] The working principle of this solution is: when the external 24V power supply is normally supplied, the power supply circuit and the power-off detection circuit connected to the external power supply work normally, and the power supply circuit outputs 5V and 3.3V voltages respectively. At this time, the 5V voltage at the first voltage output end makes the diode D3 conductive, and the 5V voltage passes through the diode D3 and then passes through the resistor R7, the resistor R6, the resistor R5, the resistor R4 and the resistor R3 in sequence to charge the capacitor E1. The current limiting resistor composed of the resistor R7, the resistor R6, the resistor R5, the resistor R4 and the resistor R3 can prevent the power supply from starting the current limiting protection when the circuit current is large. The 3.3V output voltage at the second voltage output end is respectively supplied to the power-off detection circuit, the MCU, the data storage circuit and the MOS tube driver U4.

[0028] When the external 24V power supply is disconnected, that is, when a power outage occurs, the working steps are as follows:

[0029] In the first step, capacitor E1 starts to discharge as a power supply. Capacitor E1 continues to provide 5V voltage to the first voltage output terminal of the power supply circuit through the low voltage difference diode D2, so that the second voltage output terminal normally outputs 3.3V voltage. Diode D1 can ensure that the voltage on the secondary DCDC converter U6 will not be reversed. At this time, the power-off detection circuit, MCU and data storage circuit keep working.

[0030] In the second step, after the 24V power supply is turned off, the KZ signal output by the photocoupler U2 of the power-off detection circuit will change (in this specific embodiment, the KZ signal changes from a high-level signal to a low-level signal).

[0031] Step 3: After the MCU detects that the KZ signal is pulled low, the first signal output terminal of the MCU outputs a signal to cause the memory U1 in the data storage circuit to start data storage, and the field parameters are stored in the non-volatile memory U1 through the IIC bus.

[0032] Step 4. When the storage is completed, the signal output from the second signal output terminal of the MCU to the MOS tube driver control terminal changes, that is, the MCU will pull the DYXF output signal from low to high to open the discharge circuit.

[0033] Step 5. After the DYXF output signal is pulled high, the MOS tube driver gives a start signal to the gate of the MOS tube Q1, and the MOS tube Q1 is turned on. The residual electricity on the capacitor E1 is quickly discharged through the discharge loop formed by the resistor R3, the resistor R4, the resistor R5, the resistor R6, the resistor R7 and the MOS tube Q1, and the whole circuit stops working.

[0034] Therefore, after the control device loses power, this solution uses the power on capacitor E1 to enable the memory to quickly store the parameters. On the other hand, after the parameter storage is completed, the discharge circuit formed by capacitor E1, resistor R3, resistor R4, resistor R5, resistor R6, resistor R7 and MOS tube Q1 is used to quickly dissipate the residual power on capacitor E1, thereby avoiding the safety risks that may be caused by the residual power. At the same time, by selecting the capacity of capacitor E1, the residual power retention time and the power-off speed can be controlled to achieve the purpose of controllable residual power retention time. In specific use, the capacity of capacitor E1 can control the length of the residual power retention time. A large capacity can maintain a longer residual power time, but the power is off slowly. The discharge circuit can quickly clear the residual power after the storage is completed. E1 can select a suitable size according to the on-site conditions and needs to ensure that the on-site parameters can be stored smoothly.

[0035] Compared with the existing technology, the circuit of this scheme adopts a closed-loop control method of power-off monitoring, on-site parameter storage, and power discharge, thereby ensuring the rapid dissipation of the system's residual power after parameter storage. The rapid power-off not only ensures the safety of the control equipment working site, but also ensures the reliability of the control equipment after repeated power-on.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit the technical solution. Ordinary technicians in this field should understand that those modifications or equivalent replacements of the technical solution of the utility model without departing from the purpose and scope of the technical solution of the utility model should be included in the scope of the claims of the utility model.

Claims

1. A field parameter power-off storage circuit without residual power, characterized in that: The invention comprises a power supply circuit, a power-off detection circuit, an MCU, a data storage circuit and an electric quantity discharge circuit, wherein the power supply circuit and the power-off detection circuit are respectively connected to an external power supply, the power supply circuit comprises a primary DCDC converter and a secondary DCDC converter, the output end of the primary DCDC converter serves as a first voltage output end, the output end of the secondary DCDC converter serves as a second voltage output end, the electric quantity discharge circuit comprises a capacitor E1, a diode D2, a diode D3, a current limiting resistor R and a MOS tube Q1, the cathode of the diode D2 and the anode of the diode D3 are simultaneously connected to the first voltage output end, the anode of the diode D2 is connected to the positive electrode of the capacitor E1 and one end of the current limiting resistor R, the negative electrode of the capacitor E1 is grounded, the other end of the current limiting resistor R is simultaneously connected to the cathode of the diode D3 and the drain of the MOS tube Q1, the source of the MOS tube Q1 is grounded, and the gate of the MOS tube Q1 is connected to a MOS tube driver; the second voltage output end is respectively connected to the power-off detection circuit, the MCU, the data storage circuit and the MOS tube driver, the output end of the power-off detection circuit is connected to the signal input end of the MCU, the first signal output end of the MCU is connected to the data storage circuit, and the second signal output end of the MCU is connected to the control end of the MOS tube driver.

2. The field parameter power-off storage circuit without residual power according to claim 1, characterized in that: The power supply circuit further includes a diode D1 , a cathode of the diode D1 is connected to the input end of the first-stage DCDC converter, and an anode of the diode D1 is used to be connected to an external power supply.

3. The field parameter power-off storage circuit without residual power according to claim 1, characterized in that: The power-off detection circuit protects the photocoupler U2, the anode of the photocoupler U2 is connected to the external power supply, the cathode of the photocoupler U2 is grounded, the collector of the photocoupler U2 is connected to the second voltage output end, and the emitter of the photocoupler U2 is connected to the signal input end of the MCU through a resistor R11.

4. The field parameter power-off storage circuit without residual power according to claim 3 is characterized in that: The power-off detection circuit also includes a resistor R10, a resistor R12 and a capacitor C2, one end of the resistor R10 is connected to an external power supply, the other end of the resistor R10 is connected to the anode end of the photoelectric coupler U2, one end of the resistor R12 and one end of the resistor R11 are both connected to the emitter of the photoelectric coupler U2, the other end of the resistor R12 is grounded, the other end of the resistor R11 is simultaneously connected to one end of the capacitor C2 and the signal input end of the MCU, and the other end of the capacitor C2 is grounded.

5. The field parameter power-off storage circuit without residual power according to claim 1, characterized in that: The current limiting resistor R includes a resistor R3, a resistor R4, a resistor R5, a resistor R6 and a resistor R7 connected in series, and the resistor R3, the resistor R4, the resistor R5, the resistor R6 and the resistor R7 have the same resistance value.

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