CN102694414B - Gapless automatic switching device for intelligent dual direct-current power supply - Google Patents

Abstract

The invention belongs to the field of automation control engineering, and in particular relates to a double direct current power supply seamless automatic switching device with a power supply state monitoring function. The invention is composed of a resistor, a light emitting diode, a diode, a voltage regulator tube, a voltage comparator, a field effect tube, a high-precision high-current power switch, an inverter, a microcontroller, and a CAN transceiver. In the present invention, there is no gap in the switching of the power supply, so as to ensure the continuous and uninterrupted supply of direct current. The control part adopts the enhanced MOSFET as the voltage drive, and basically does not increase the power consumption of the original system during operation. After the switching action is completed, the auxiliary power supply supplies power to the equipment through a high-precision high-current power switch, with minimal energy loss. The working state of the power supply can be programmed for the microcontroller and transmitted through the CAN transceiver to achieve the purpose of remote monitoring. Therefore, the present invention has the advantages of high efficiency, simple and reliable circuit, low cost, low energy consumption, strong adaptability and benefit for remote monitoring.

Description

An Intelligent Dual-DC Power Supply Seamless Automatic Switching Device

technical field

The invention belongs to the field of automation control engineering, and in particular relates to a double direct current power supply seamless automatic switching device with a power supply state monitoring function.

Background technique

With the development of science and technology and the application of high-end precision devices, higher requirements are put forward for power quality and power supply reliability. For important occasions such as hospitals, shopping malls, banks, chemicals, high-rise buildings, military facilities, and fire protection, two-way power supplies are required. To ensure the reliability of power supply, especially in the above special occasions involving the field of automation control engineering equipment, it is even more necessary to be equipped with two or even multiple power supplies, and a device that can reliably switch between the two power supplies to ensure The power supply is uninterrupted to meet the normal operation of the equipment, and at the same time ensure the uninterrupted monitoring and control of the running equipment. It is common that some electronic instruments need to protect the data in the random access memory RAM without power failure. Another case is that the clock circuit continues to record time information without power failure protection. At present, the following methods are generally adopted for the switching of the standby power supply: 1. Standby type: when the switching unit detects a power failure, it switches to the standby power supply. The backup power has the following problems: (1) It takes a certain amount of time to switch, which may cause the device to restart; (2) Most of the backup power is powered by batteries, which need to be tested and replaced regularly, and the cost is high; 2. Online Mode: the backup power supply is always connected to the device, but its output voltage is slightly lower than the external power supply, so when the external power supply is normal, the backup power supply cannot output power to the device, and when there is a power failure or the external power supply voltage is insufficient, the backup power supply will The device is powered. In this way, because the backup power supply is always in a state of waiting for power supply, there is a problem of large power loss, which is not conducive to energy saving. Both of the above two power supply switching methods cannot fully guarantee the seamless switching of the power supply.

After searching the literature of the prior art, it is found that the Chinese patent publication number CN201750208U, the publication date is 2011.02.16, the patent name is: dual power supply automatic switching circuit for embedded equipment with backup battery, and the patent reads: "This circuit has Two sets of power supply, composed of AC/DC mains 220V conversion module and backup battery, the microprocessor of the embedded device detects the power supply status of the mains and the power of the battery in real time, the detection signal of the power supply status of the mains and the power of the backup battery The detection signals are respectively connected to the ports of the MCU, and the on-off control of the relay coil is realized through the MCU to realize power switching and charge and discharge management of the backup battery. Its shortcoming is that one of the two-way power supplies of this circuit is powered by a storage battery, which has the problems of insufficient service life, long-term power supply capacity, and cumbersome management of battery charging and discharging, and cannot realize real-time monitoring of the power supply of the two-way power supply Function, due to the existence of relays, the purpose of seamless switching between two power supplies cannot be fully achieved.

Contents of the invention

The purpose of the present invention is to provide a dual power supply automatic switching device which can realize remote power supply state monitoring and automatic seamless switching.

The purpose of the present invention is achieved like this:

The invention consists of resistors, light emitting diodes, diodes, voltage regulator tubes, voltage comparators, field effect tubes, high-precision high-current power switches, inverters, microcontrollers, and CAN transceivers, and is characterized in that:

The main power supply (V1) leads to 4 connection points, and the first connection point of the main power supply is connected to the +Vbb port of the first current power switch (U5);

The second connection point of the main power supply is connected to one end of the first resistor (R1), the other end of the first resistor (R1) is connected to one end of the first light-emitting diode (D1), and the other end of the first light-emitting diode (D1) is grounded;

The third connection point of the main power supply is connected to the anode of the first diode (D2);

The fourth connection point of the main power supply is connected to the anode of the second diode (D3), the cathode of the second diode (D3) is connected to one end of the fifth resistor (R5), and the other end of the fifth resistor (R5) is connected to One end of the tenth resistor (R10) is connected, the other end of the tenth resistor (R10) is grounded, and the connection point is drawn between the fifth resistor (R5) and the tenth resistor (R10), and the first voltage comparator (U1 ) of the 3rd pin is connected to the 2nd pin of the second voltage comparator (U2);

The cathode of the first diode (D2) leads to five connection points, the first connection point of the first diode is connected to one end of the fourth resistor (R4), and the other end of the fourth resistor (R4) is connected to the first regulator The anode of the tube (D4) is connected, the negative pole of the first voltage regulator tube (D4) is grounded, the connection point is drawn between the fourth resistor (R4) and the first voltage regulator tube (D4), and the second voltage comparator (U2) The 3rd pin is connected;

The second connection point of the first diode is connected to one end of the sixth resistor (R6), the other end of the sixth resistor (R6) is connected to the anode of the second voltage regulator tube (D5), and the second voltage regulator tube (D5) The negative electrode of the ground is grounded, and the connection point is drawn between the sixth resistor (R6) and the second voltage regulator tube (D5), and connected to the second pin of the first voltage comparator (U1);

The 3rd connection point of the first diode and the 1st pin of the first voltage comparator (U1), the 1st pin of the second voltage comparator (U2), the 1st pin of the third voltage comparator (U3) pin, the first pin of the fourth voltage comparator (U4), the fourth pin of the first voltage comparator (U1), the fourth pin of the second voltage comparator (U2), the third voltage comparator The 4th pin of (U3) and the 4th pin of the fourth voltage comparator (U4) are grounded;

The fourth connection point of the first diode is connected to one end of the second resistor (R2), and the other end of the second resistor (R2) is connected to the anode of the third voltage regulator tube (D6). The third voltage regulator tube (D6) The cathode of the ground is grounded, and the connection point is drawn between the second resistor (R2) and the third voltage regulator tube (D6), and the fifth pin of the first voltage comparator (U1) and the second voltage comparator (U2) Pin 5, grid G of the first FET (Q1), grid G of the second FET (Q2), one end of the ninth resistor (R9), and anode of the fourth regulator (D7) , the input terminal of the first inverter (U7) is connected, the other end of the ninth resistor (R9) and the cathode of the fourth voltage regulator tube (D7) are grounded;

The fifth connection point of the first diode is connected to one end of the third resistor (R3), and the other end of the third resistor (R3) is connected to the drain D of the second field effect transistor (Q2);

The source S of the field effect transistor Q1 is grounded, and the drain D is connected to the IN terminal of the first high-precision high-current power switch (U5);

The source S of the field effect transistor Q2 is grounded, and the drain D is respectively connected to the gate G of the third field effect transistor (Q3), one end of the seventh resistor (R7), and the anode of the fifth voltage regulator transistor (D8). The other end of the seven resistors (R7) and the cathode of the fifth voltage regulator tube (D8) are grounded.

The source S of the third field effect transistor (Q3) is grounded, and the drain D is connected to the IN terminal of the second high-precision high-current power switch (U6).

The auxiliary power supply (V2) leads to 4 connection points, and the first connection point of the auxiliary power supply is connected to the +Vbb port of the second high-precision high-current power switch (U6);

The second lead-out point of the auxiliary power supply is connected to one end of the eleventh resistor (R11), the other end of the eleventh resistor (R11) is connected to one end of the second light-emitting diode (D10), and the other end of the second light-emitting diode (D10) grounding;

The third lead-out point of the auxiliary power supply is connected to the anode of the third diode (D11);

The fourth outlet point of the auxiliary power supply is connected to the anode of the fourth diode (D12), the cathode of the fourth diode (D12) is connected to one end of the fifteenth resistor (R15), and the other end of the fifteenth resistor (R15) One end is connected to one end of the sixteenth resistor (R16), and the other end of the sixteenth resistor (R16) is grounded, where the connection point is drawn between the fifteenth resistor (R15) and the sixteenth resistor (R16), and connected to the sixteenth resistor (R16). The third pin of the three-voltage comparator (U3) is connected to the second pin of the fourth voltage comparator (U4);

The cathode of the third diode (D11) leads to 4 connection points, the first connection point of the third diode is connected to one end of the twelfth resistor (R12), the other end of the twelfth resistor (R12) is connected to the sixth The anode of the regulator tube (D13) is connected, the negative pole of the sixth regulator tube (D13) is grounded, and the connection point is drawn at the connection between the twelfth resistor (R12) and the sixth regulator tube (D13), and compared with the fifth voltage connected to the third pin of the device (U5);

The second lead-out point of the third diode is connected to one end of the thirteenth resistor (R13), the other end of the thirteenth resistor (R13) is connected to the anode of the seventh voltage regulator tube (D14), and the seventh voltage regulator tube ( The negative electrode of D14) is grounded, and the connection point is drawn at the connection between the thirteenth resistor (R13) and the seventh voltage regulator tube (D14), and connected to the second pin of the third voltage comparator (U13);

The third lead-out point of the third diode is connected to the first pin of the third voltage comparator (U3) and the first pin of the fourth voltage comparator (U4);

The fourth lead-out point of the third diode is connected to one end of the fourteenth resistor (R14), the other end of the fourteenth resistor (R14) is connected to the anode of the eighth voltage regulator tube (D15), and the eighth voltage regulator tube ( The cathode of D15) is grounded, and the connection point is drawn between the fourteenth resistor (R14) and the eighth voltage regulator tube (D15), which is connected to the fifth pin of the third voltage comparator (U3), the fourth voltage comparator ( The fifth pin of U4), one end of the seventeenth resistor (R17), one end of the eighteenth resistor (R18), the other end of the seventeenth resistor (R17) is grounded, the other end of the eighteenth resistor (R18) One end is respectively connected to the anode of the ninth voltage stabilizing tube (D16) and the input end of the second inverter (U8), and the cathode of the ninth voltage stabilizing tube (D16) is grounded;

The OUT end of the first high-precision high-current power switch (U5) is connected to one end of the eighth resistor (R8), and the other end of the eighth resistor (R8) is connected to the anode of the third light-emitting diode (D9), and the third light-emitting diode (D9) ), the cathode of the first high-precision high-current power switch (U5) is connected to one end of the twentieth resistor (R20), and the other end of the twentieth resistor (R20) is grounded;

The OUT end of the second high-precision high-current power switch (U6) is connected to one end of the nineteenth resistor (R19), and the other end of the nineteenth resistor (R19) is connected to the anode of the fourth light-emitting diode (D17), and the fourth light-emitting diode The cathode of (D17) is grounded, the IS terminal of the second high-precision high-current power switch (U6) is connected to one end of the twenty-fourth resistor (R24), and the other end of the twenty-fourth resistor (R24) is grounded.

The output of the first inverter (U7) is connected to the PA1 pin of the microcontroller (U9), the output of the second inverter (U8) is connected to the PA0 pin of the microcontroller (U9), and the microcontroller The PM0/RXCAN3 pin of the device (U8) is connected to the CRXD pin of the CAN transceiver (U9), and the PM0/TXCAN3 pin of the microcontroller (U8) is connected to the CTXD pin of the CAN transceiver (U9). The transceiver U9 transmits the signal to the remote device for display.

When the power supply of the main power supply (V1) is normal, through the first voltage comparator (U1), the second voltage comparator (U2), and the first field effect transistor (Q1), ensure that the first high-precision high-current power switch (U5) ) is in the conduction state, the first high-precision high-current power switch (U5) outputs the direct current of the main power supply V1, and at the same time indicates through the third light-emitting diode (D9).

When the power supply of the main power supply (V1) is normal, the third voltage comparator (U3), the fourth voltage comparator (U4), the second field effect transistor (Q2), and the third field effect transistor (Q3) are used to ensure that the first The second high-precision high-current power switch (U6) is in the cut-off state, and the auxiliary power supply V2 does not provide direct current, and at the same time indicates through the fourth light-emitting diode (D17).

The 5th pin of the first voltage comparator (U1) is connected to the 5th pin of the second voltage comparator (U2), which provides the turn-on voltage for the gate G of the first field effect transistor (Q1) and at the same time provides the first The inverter (U7) provides direct current with a fixed voltage; the fifth pin of the third voltage comparator (U3) is connected to the fifth pin of the fourth voltage comparator (U4), which is the second inverter ( U8) provides direct current at a fixed voltage.

The first field effect transistor (Q1) controls the on-off of the first high-precision high-current power switch (U5); the third field-effect transistor (Q3) controls the on-off of the second high-precision high-current power switch (U6).

The supply voltage range of the main power supply is {20V, 28V}, and the supply voltage range of the auxiliary power supply is {20V, 28V}.

The voltage comparator is a window voltage comparator.

The model of the microcontroller (U9) is: AT90CAN series, P8XC592, 82C200, 82526, 82527, MC9S08 series, MC9S12 series or 72005.

The CAN transceiver (U10) adopts the models: ISO1050, PCA82C251, CTM1050, ADM3054 or MAX13041.

The beneficial effects of the present invention are:

In the present invention, there is no gap in the switching of the power supply, so as to ensure the continuous and uninterrupted supply of direct current. The control part adopts the enhanced MOSFET as the voltage drive, and basically does not increase the power consumption of the original system during operation. After the switching action is completed, the auxiliary power supply supplies power to the equipment through a high-precision high-current power switch, with minimal energy loss. When the main power supply exceeds the working range, the auxiliary power supply V2 quickly and automatically completes the power conversion work. The working status of the power supply can be programmed by the microcontroller and transmitted through the CAN transceiver to achieve the purpose of remote monitoring. The devices used are switching control devices without special requirements such as high power and high voltage. Therefore, the present invention has the advantages of high efficiency, simple and reliable circuit, low cost, low energy consumption, strong adaptability, and remote monitoring.

Description of drawings

Fig. 1 is a circuit diagram of an intelligent dual DC power supply seamless automatic switching device of the present invention.

Detailed ways

Below in conjunction with example the present invention is described in more detail:

As shown in Figure 1: when the main power supply is powered, the on-off of U5 is controlled by Q1 to realize the power supply of the main power V1. At the same time, the on-off of Q2 is controlled by Q1, and the on-off of Q3 is controlled by Q2, and the on-off of U6 is controlled by Q3. Make sure that the auxiliary power supply V2 is in a power-off state when the main power supply V1 supplies power. The voltage range of the main power supply V1 is controlled by U1. When the voltage of the main power supply V1 exceeds the specified voltage range, the power supply of the main power supply V1 is cut off and at the same time it is converted into the power supply mode of the auxiliary power supply V2. When the main and auxiliary power supply are powered separately, the light-emitting diodes D9 and D17 respectively indicate the power supply of the main and auxiliary power supply. At the same time, the information of the main and auxiliary power supply respectively is transmitted to the U9 microcontroller by State1 and State2 through the inverter U7 and U8, and then It can be transmitted to the monitoring site through the CAN transceiver U10.

The present invention is further specifically:

1. The main power supply V1 provides DC power. The power supply of the main power supply V1 is realized by U1 and U2 voltage comparators in the form of window voltage comparators. The upper limit voltage is obtained by R4 and D4, the lower limit voltage is obtained by R6 and D5, and the input terminal voltage is obtained by R5 and R10. When the main power supply V1 is within the working range, the output terminals of U1 and U2 are at high level, and when the voltage exceeds the working range, the output terminals of U1 and U2 are at low level.

2. The on-off of the field effect transistor Q1 is controlled by the voltage comparators U1 and U2. When the main power supply V1 is within the normal operating voltage range, the output terminals of the voltage comparators U1 and U2 are connected to the gate G of the field effect transistor Q1, and the output terminal is at a high level to ensure that the field effect transistor Q1 is in the conduction state. When the main power supply After the working voltage of V1 exceeds the specified range, the voltage comparators U1 and U2 output low level, and control Q1 to be in the disconnected state.

3. The on-off of the field effect transistor Q2 is controlled by the voltage comparators U1 and U2. When the main power supply V1 is within the normal operating voltage range, the output terminals of the voltage comparators U1 and U2 are connected to the gate G of the field effect transistor Q2, and the output terminal is at a high level to ensure that the field effect transistor Q2 is in the conduction state. When the main power supply After the working voltage of V1 exceeds the specified range, the voltage comparators U1 and U2 output low level, and control Q2 to be in the disconnected state.

4. The on-off of the field effect transistor Q3 is controlled by the field effect transistor Q2. The drain D of Q2 is connected to the gate G of Q3. When the main power supply V1 is in the working state, Q2 is turned on, so that the drain D of Q2 is in a low level state, that is, the gate G of Q3 is in a low level state, and Q3 In the off state, the drain D of Q3 is in a high potential state. Conversely, Q3 is on when Q2 is off.

5. The on-off of the high-precision high-current power switch U5 is controlled by the effect transistor Q1. When the main power supply V1 works within the specified range, Q1 remains on, and the drain D of Q1 is grounded, so that the IN terminal of the high-precision and high-current power switch U5 is grounded, ensuring that the high-precision and high-current power switch U5 is in the on-state, realizing The main power supply V1 supplies power.

6. The on-off of the high-precision high-current power switch U6 is controlled by the effect transistor Q3. When the main power supply V1 works within the specified range, Q2 remains on, the drain D of Q2 is at low level, and the low level is sent to the gate G of Q3 to ensure that Q2 is in the off state, and the drain D of Q2 remains at high level. level, so that the IN terminal of the high-precision and high-current power switch U6 maintains a high level, ensuring that the high-precision and high-current power switch U6 is in the off state, and ensuring that the auxiliary power supply V2 does not supply power when the main power supply V1 supplies power.

7. The auxiliary power supply V2 provides direct current. The power supply of the auxiliary power supply V2 is realized specifically by the voltage comparators U3 and U4, and the principle and working method are the same as those of U1 and U2.

When the switching unit of the present invention exceeds the working range of the main power supply V1, the power supply line will switch to the auxiliary power supply V2 without any gap.

The circuit connection relation of the present invention is as shown in Figure 1:

The two output pins 5 of the voltage comparator U1 and 5 of U2 are connected to provide the turn-on voltage for the gate G of the field effect transistor Q1 and provide a fixed voltage direct current for State1 at the same time.

The source S of the FET Q1 is grounded, the gate G is connected to the outputs of the voltage comparators U1 and U2, and the drain D is connected to the IN of the high-precision high-current power switch U5 to control the high-precision high-current power switch U5 on and off.

The source S of the FET Q3 is grounded, the gate G is connected to the drain D of Q2, and the drain D is connected to the IN of the high-precision high-current power switch U6 to control the on-off of the high-precision high-current power switch U6.

Two output pins 5 of the voltage comparator U3 and 5 of U4 are connected to provide a fixed voltage direct current for State2.

State1 and State2 are connected to the PA1 and PA0 pins of the microcontroller U9 through the inverters U7 and U8, and are connected to the CAN transceiver U10 by the PM0/RXCAN3 and PM0/TXCAN3 pins of the microcontroller U9 respectively. The CRXD and CTXD are connected, and finally the CAN transceiver U9 transmits the signal to the remote device for display.

The working principle of the present invention is as follows:

When the power supply of the main power supply V1 is normal, the output terminals of the voltage comparators U1 and U2 are at high level. The effect transistor Q1 is in the conduction state, the drain D of the field effect transistor Q1 is grounded, and the drain D is connected to the IN interface of the high-precision high-current power switch U5. The high-precision high-current power switch is in the conduction state when the IN terminal is grounded. The high-precision high-current power switch U5 is turned on, and the load circuit is in the power supply state of the main power supply V1, which is indicated by the light-emitting diode D9; the other path is sent to the gate G of the field effect transistor Q2, which is used as the turn-on voltage to make the field effect transistor Q2 in the conduction state. The drain D of the field effect transistor Q2 is grounded, and the drain D is connected to the gate G of the field effect transistor Q3. The low level ensures that the field effect transistor Q3 is in an off state, and the drain D of the field effect transistor Q3 is guaranteed to be at a high level. The level signal is connected to the IN interface of the high-precision high-current power switch U6, so that the high-precision high-current power switch U6 is in the cut-off state to ensure that the auxiliary power supply V2 does not provide DC power. The third circuit is stabilized by the voltage regulator tube D7, and the DC power of the stable voltage is drawn from the State1, and the status of the main power supply V1 can be judged accordingly. The auxiliary power supply V2 supplies DC power of a fixed voltage to State2 via the voltage comparators U3 and U4, and the state of the auxiliary power supply V2 can be judged accordingly.

When the power supply of the main power supply V1 is not normal, the U1, U2, U3, and U4 power supply cables can ensure that the power supply of the voltage comparators U1, U2 is provided by the auxiliary power supply V2, ensuring that the voltage comparators U1, U2 are in the working state, and the output terminals The low level signal is sent to two circuits, one of which is sent to the gate G of the field effect transistor Q1, so that the field effect transistor Q1 is in the disconnected state, and the drain D of the field effect transistor Q1 is pulled high level, the drain D of field effect transistor Q1 is connected to the IN interface of the high-precision high-current power switch U5, the high-precision high-current power switch is in the cut-off state when the IN terminal is not grounded, the high-precision high-current power switch U5 is turned off, and the main The power supply V1 stops supplying power to the load circuit; the other route is sent to the gate G of the field effect transistor Q2, so that the field effect transistor Q2 is in the cut-off state, the drain D of the field effect transistor Q2 is at a high level, and the drain D of the field effect transistor Q2 is connected to The gate G of the field effect transistor Q3 is connected, and the high level ensures that the field effect transistor Q3 is in the conduction state, so that the drain D of the field effect transistor Q3 is grounded, and the drain D is connected to the IN interface of the high-precision high-current power switch U6. The high-precision high-current power switch is in the conduction state when the IN terminal is grounded, the high-precision high-current power switch U6 is turned on, and the load circuit is powered by the auxiliary power supply V2, which is indicated by the light-emitting diode D17. This ensures that the direct current is continuously supplied to the electrical equipment.

The first pins of the high-precision high-current power switches U5 and U6 are grounded after passing through a resistor, and the current of the first pins is proportional to the current of the load circuit, which can protect the load circuit.

In the main and auxiliary power supply circuits, D1 and D10 are power supply indicator light-emitting diodes, and D9 and D17 are load power supply indicator light-emitting diodes.

State1 and State2 are connected to PA1 and PA0 pins of microcontroller U9 after being processed by inverters U7 and U8. After processing by microcontroller U9, the information is transmitted to the remote device through CAN transceiver U10 show.

Work process of the present invention is:

The two DC power supplies of the system are V1 and V2 respectively. The normal power supply voltages of V1 and V2 are both 24V, but there are certain fluctuations in the actual power supply voltage. The system detects such fluctuations, and at the same time automatically completes power supply switching and power supply abnormal information reporting function.

Resistor R4 and Zener tube D4 are used to determine the lower limit of the allowable fluctuating voltage of the main power supply V1, such as 20V; resistor R6 and Zener tube D5 are used to determine the upper limit of the allowable fluctuating voltage of the main power supply V1, such as 28V. Amplifiers U1 and U2 form a dual-limit comparator.

① When the power supply voltage of V1 is in the interval {20V, 28V}, the output terminal State1 of the dual-limit comparator is at a high level, and this signal can control the conduction of the field effect transistor Q1, that is, the drain of Q1 is grounded and the device U5 is turned on. The output terminal State1 is at a high level and at the same time controls the conduction of the field effect transistor Q2, and the drain of Q2 is grounded, then the gate of Q3 is extremely low voltage, Q3 is turned off, and the device U6 is turned off. At this moment, the power supply of the main power supply V1 is normal and is the power supply.

② When the power supply voltage of V1 is not in the interval {20V, 28V}, the output terminal State1 of the dual-limit comparator is at a low level, and this signal can control the cut-off of the field effect transistor Q1 and the device U5. The output terminal State1 is at low level and controls the field effect transistor Q2 to be cut off, and then the gate of Q3 is extremely high voltage through the voltage division effect of the resistor R3 and the resistor R7, Q3 is turned on, and the device U6 is turned off. At this time, the power supply of the main power supply V1 is abnormal, and the auxiliary power supply V2 is used for power supply.

Resistor R12 and voltage regulator tube D13 are used to determine the lower limit of the allowable fluctuation voltage of the auxiliary power supply V2, such as 20V; resistor R13 and voltage regulator tube D14 are used to determine the upper limit of the allowable fluctuation voltage of the auxiliary power supply V2, such as 28V. Amplifiers U3 and U4 form a dual-limit comparator. When the V2 power supply voltage is in the interval {20V, 28V}, the output terminal State2 of the dual-limit comparator is at a high level. When the V2 power supply voltage is not in the interval {20V, 28V}, The output terminal State2 of the double limit comparator is low level.

After the power supply state information State1 and State2 of the main power supply and the auxiliary power supply are reversed, the microcontroller U9 integrated with the CAN module and the CAN transceiver U10 are reported to complete the detection function of the power supply status of the main power supply and the auxiliary power supply.

The models adopted by the microcontroller U9 of the present invention are: AT90CAN series, P8XC592, 82C200, 82526, 82527, MC9S08 series, MC9S12 series, and 72005.

The models used by CAN transceiver U10 are: ISO1050, PCA82C251, CTM1050, ADM3054, MAX13041.

Claims (7)

1. An intelligent dual DC power supply seamless automatic switching device, which is composed of resistors, light-emitting diodes, diodes, voltage regulator tubes, voltage comparators, field effect tubes, current power switches, inverters, microcontrollers, and CAN transceivers , which is characterized by: The main power supply (V1) leads to 4 connection points, and the first connection point of the main power supply is connected to the +Vbb port of the first current power switch (U5); The second connection point of the main power supply is connected to one end of the first resistor (R1), the other end of the first resistor (R1) is connected to one end of the first light-emitting diode (D1), and the other end of the first light-emitting diode (D1) is grounded; The third connection point of the main power supply is connected to the anode of the first diode (D2); The fourth connection point of the main power supply is connected to the anode of the second diode (D3), the cathode of the second diode (D3) is connected to one end of the fifth resistor (R5), and the other end of the fifth resistor (R5) is connected to One end of the tenth resistor (R10) is connected, and the other end of the tenth resistor (R10) is grounded, wherein a connection point is drawn between the fifth resistor (R5) and the tenth resistor (R10), and the first voltage comparator (U1 ) of the inverting input terminal and the non-inverting input terminal of the second voltage comparator (U2) are connected; The cathode of the first diode (D2) leads to five connection points, the first connection point of the first diode is connected to one end of the fourth resistor (R4), and the other end of the fourth resistor (R4) is connected to the first regulator The cathode of the tube (D4) is connected, the anode of the first voltage regulator tube (D4) is grounded, the connection point is drawn between the fourth resistor (R4) and the first voltage regulator tube (D4), and the second voltage comparator (U2) connected to the inverting input; The second connection point of the first diode is connected to one end of the sixth resistor (R6), the other end of the sixth resistor (R6) is connected to the cathode of the second voltage regulator tube (D5), and the second voltage regulator tube (D5) The anode of the anode is grounded, and a connection point is drawn between the sixth resistor (R6) and the second voltage regulator tube (D5), and connected to the non-inverting input terminal of the first voltage comparator (U1); The third connection point of the first diode and the positive pole of the power supply pin of the first voltage comparator (U1), the positive pole of the power supply pin of the second voltage comparator (U2), and the power supply pin of the third voltage comparator (U3) The positive pole and the positive pole of the power supply pin of the fourth voltage comparator (U4) are connected, the negative pole of the power supply pin of the first voltage comparator (U1), the negative pole of the power supply pin of the second voltage comparator (U2), and the third voltage comparator The negative pole of the power supply pin of (U3) and the negative pole of the power supply pin of the fourth voltage comparator (U4) are grounded; The fourth connection point of the first diode is connected to one end of the second resistor (R2), and the other end of the second resistor (R2) is connected to the cathode of the third voltage regulator tube (D6), and the third voltage regulator tube (D6) The anode of the ground is grounded, and the connection point is drawn between the second resistor (R2) and the third voltage regulator tube (D6), and the output terminal of the first voltage comparator (U1) and the output terminal of the second voltage comparator (U2) , the grid G of the first field effect transistor (Q1), the grid G of the second field effect transistor (Q2), one end of the ninth resistor (R9), the cathode of the fourth voltage regulator transistor (D7), the first reverse The input terminal of the directing device (U7) is connected, the other end of the ninth resistance (R9) and the anode of the fourth regulator tube (D7) are grounded; The fifth connection point of the first diode is connected to one end of the third resistor (R3), and the other end of the third resistor (R3) is connected to the drain D of the second field effect transistor (Q2); The source S of the field effect transistor (Q1) is grounded, and the drain D is connected to the IN terminal of the first current power switch (U5); The source S of the field effect transistor (Q2) is grounded, and the drain D is respectively connected to the grid G of the third field effect transistor (Q3), one end of the seventh resistor (R7), and the cathode of the fifth voltage regulator transistor (D8). , the other end of the seventh resistor (R7) and the anode of the fifth voltage regulator tube (D8) are grounded; The source S of the third FET (Q3) is grounded, and the drain D is connected to the IN terminal of the second current power switch (U6); The auxiliary power supply (V2) leads to 4 connection points, and the first connection point of the auxiliary power supply is connected to the +Vbb port of the second current power switch (U6); The second lead-out point of the auxiliary power supply is connected to one end of the eleventh resistor (R11), the other end of the eleventh resistor (R11) is connected to one end of the second light-emitting diode (D10), and the other end of the second light-emitting diode (D10) grounding; The third lead-out point of the auxiliary power supply is connected to the anode of the third diode (D11); The fourth outlet point of the auxiliary power supply is connected to the anode of the fourth diode (D12), the cathode of the fourth diode (D12) is connected to one end of the fifteenth resistor (R15), and the other end of the fifteenth resistor (R15) One end is connected to one end of the sixteenth resistor (R16), and the other end of the sixteenth resistor (R16) is grounded, where the connection point is drawn between the fifteenth resistor (R15) and the sixteenth resistor (R16), and connected to the sixteenth resistor (R16). The inverting input terminal of the three-voltage comparator (U3) is connected to the non-inverting input terminal of the fourth voltage comparator (U4); The cathode of the third diode (D11) leads to 4 connection points, the first connection point of the third diode is connected to one end of the twelfth resistor (R12), the other end of the twelfth resistor (R12) is connected to the sixth The cathode of the voltage regulator tube (D13) is connected, the anode of the sixth voltage regulator tube (D13) is grounded, and the connection point is drawn at the connection between the twelfth resistor (R12) and the sixth voltage regulator tube (D13), and compared with the fifth voltage The inverting input terminal of device (U5) is connected; The second connection point of the third diode is connected to one end of the thirteenth resistor (R13), the other end of the thirteenth resistor (R13) is connected to the positive pole of the seventh voltage regulator tube (D14), and the seventh voltage regulator tube ( The negative electrode of D14) is grounded, and the connection point is drawn at the connection between the thirteenth resistor (R13) and the seventh voltage regulator tube (D14), and connected to the non-inverting input terminal of the third voltage comparator (U13); The third connection point of the third diode is connected to the positive pole of the power supply pin of the third voltage comparator (U3) and the positive pole of the power supply pin of the fourth voltage comparator (U4); The fourth connection point of the third diode is connected to one end of the fourteenth resistor (R14), the other end of the fourteenth resistor (R14) is connected to the cathode of the eighth voltage regulator tube (D15), and the eighth voltage regulator tube ( The anode of D15) is grounded, and the connection point is drawn between the fourteenth resistor (R14) and the eighth voltage regulator tube (D15), which is connected to the output terminal of the third voltage comparator (U3) and the fourth voltage comparator (U4) The output end of the seventeenth resistor (R17) and one end of the eighteenth resistor (R18) are connected, the other end of the seventeenth resistor (R17) is grounded, and the other end of the eighteenth resistor (R18) is connected to the The cathode of the nine voltage regulator tubes (D16) is connected to the input end of the second inverter (U8), and the anode of the ninth voltage regulator tube (D16) is grounded; The OUT end of the first current power switch (U5) is connected to one end of the eighth resistor (R8), the other end of the eighth resistor (R8) is connected to the anode of the third light-emitting diode (D9), and the cathode of the third light-emitting diode (D9) grounding, the diagnostic feedback end of the first current power switch (U5) is connected to one end of the twentieth resistor (R20), and the other end of the twentieth resistor (R20) is grounded; The OUT end of the second current power switch (U6) is connected to one end of the nineteenth resistor (R19), and the other end of the nineteenth resistor (R19) is connected to the anode of the fourth light-emitting diode (D17), and the fourth light-emitting diode (D17) The cathode of the second current power switch (U6) is connected to one end of the twenty-fourth resistor (R24), and the other end of the twenty-fourth resistor (R24) is grounded. 2. A kind of intelligent double DC power supply seamless automatic switching device according to claim 1, characterized in that: when the main power supply (V1) is powered normally, through the first voltage comparator (U1), the second The voltage comparator (U2) and the first field effect transistor (Q1) ensure that the first current power switch (U5) is in the conduction state, and the first current power switch (U5) outputs the main power DC, and at the same time passes through the third light-emitting diode (D9) to instruct. 3. A kind of intelligent dual DC power supply seamless automatic switching device according to claim 2, characterized in that: when the main power supply (V1) is powered normally, the third voltage comparator (U3), the fourth The voltage comparator (U4), the second FET (Q2), and the third FET (Q3) ensure that the second current power switch (U6) is in the cut-off state, and the auxiliary power supply (V2) does not provide DC power, and at the same time passes through the first Four light-emitting diodes (D17) indicate. 4. A kind of intelligent dual DC power supply seamless automatic switching device according to claim 3, characterized in that: the output terminal of the first voltage comparator (U1) and the output terminal of the second voltage comparator (U2) connected to provide the turn-on voltage for the gate G of the first field effect transistor (Q1), and simultaneously provide the direct current of a fixed voltage for the first inverter (U7); the output terminal of the third voltage comparator (U3) is connected to the first The output terminals of the four voltage comparators (U4) are connected to provide a fixed voltage direct current for the second inverter (U8), and the voltage comparators are amplifiers. 5. A kind of intelligent dual DC power supply seamless automatic switching device according to claim 4, characterized in that: the first field effect transistor (Q1) controls the on-off of the first current power switch (U5); The third field effect transistor (Q3) controls the on-off of the second current power switch (U6). 6. A kind of intelligent double DC power supply seamless automatic switching device according to claim 5, characterized in that: the supply voltage interval of the main power supply is (20V, 28V), and the supply voltage of the auxiliary power supply (V2) The interval is (20V, 28V). 7. An intelligent dual DC power supply seamless automatic switching device according to claim 6, wherein the voltage comparator is a window voltage comparator.