Battery circuit based on hardware automatic switching

Abstract

The utility model relates to a battery circuit based on hardware automatic switching. The battery circuit comprises a PMOS tube QV2, resistors RV7, RV8 and RV10, a voltage stabilizing diode DV5, a Schottky diode DV4, a switching diode DV6 and capacitors CV3 and CV4. The MHVDD is connected with the negative electrode of the voltage stabilizing diode DV5, the positive electrode of the voltage stabilizing diode DV5 is connected with one end of the resistor RV7, and the other end of the resistor RV7 is connected with the positive electrode of the switching diode DV6, one end of the resistor RV8 and the grid electrode of the PMOS tube QV2; the negative electrode of the switch diode DV6 is connected with one end of the RV10, the negative electrode of the switch diode DV6 is connected with the DVDD, the other end of the resistor RV10 is grounded GND, the other end of the resistor RV8 is grounded GND, the drain electrode of the PMOS tube QV2 is connected with the MVDD, and the source electrode of the PMOS tube QV2 is connected with the negative electrode of the Schottky diode DV4.

Description

Technical Field

[0001] The utility model relates to a battery circuit based on hardware automatic switching, belonging to the field of circuit control. Background Art

[0002] With the continuous development and progress of smart meter technology, people's understanding of the intelligence of meters has become higher and higher. In order to maintain the normal operation of some necessary functions, the demand for batteries has become an inevitable trend. Batteries are the most common and commonly used necessities in daily life. In other words, batteries are everywhere. Batteries are a device for energy conversion and storage. They convert chemical energy or physical energy into electrical energy through reactions. In the field of smart meters, in order to meet the needs of maintaining the RTC clock during power outages, batteries are usually used to maintain the RTC clock to ensure that the RTC clock does not become disordered during power outages. When the smart meter is powered on normally, because the PMOS tube is turned on at a low level, the battery is in a state of no power supply. In the case of a power outage, the PMOS gradually begins to turn on, and the battery also supplies power to the MCU system to maintain the RTC. Through the design of smart meter hardware, the battery circuit can realize automatic switching during power outages. Using hardware to realize automatic switching of batteries during power outages not only saves the cost of firmware, but also has low cost, easy implementation, and high applicability of automatic switching circuits.

[0003] Currently common battery switching circuit (attached Figure 1 ), the device includes an adapter, a diode D1, a battery and a load R1, and a MOS tube Q1. The adapter is connected in series to the positive electrode of the diode D1, the negative electrode of the diode D1 is connected to the resistor R1, and the other end of R1 is grounded. The battery is connected in series to both ends of the resistor R1, and a PMOS tube is connected in series between the battery bat1 and the resistor R1. The drain of the PMOS tube Q1 is connected to the positive electrode of the battery bat1, the source of the MOS tube is connected to one end of the resistor R1, and the gate of the PMOS tube is connected to a pin of the control circuit of the MOS tube. The circuit controls the switching of the battery by controlling the on and off of the MOS tube Q1 through the MOS control circuit. However, the circuit has the following disadvantages: 1. The cost is high, the circuit is relatively complex, and a separate chip is required to control the MOS tube; 2. The compatibility is not high and the efficiency is low; 3. The anti-interference ability is weak. Utility Model Content

[0004] In the design process of smart meter products, most overseas market demands require the RTC clock to be maintained during power outages. The battery circuit has become an indispensable circuit in the design of smart meters. This application uses hardware to achieve an automatic switching of the battery during a power outage to maintain the RTC and other functional requirements of the smart meter during a power outage.

[0005] In order to solve the above problems, the technical solution adopted by the utility model is:

[0006] A battery circuit based on hardware automatic switching includes a PMOS tube QV2, resistors RV7, RV8, RV10, a voltage regulator diode DV5, a Schottky diode DV4, a switch diode DV6, and capacitors CV3 and CV4;

[0007] MHVDD is connected to the cathode of the voltage zener diode DV5, the anode of the voltage zener diode DV5 is connected to one end of the resistor RV7, the other end of the resistor RV7 is respectively connected to the anode of the switching diode DV6, one end of the resistor RV8, and the gate of the PMOS tube QV2;

[0008] The cathode of the switching diode DV6 is connected to one end of RV10, and the cathode of the switching diode DV6 is connected to DVDD, the other end of the resistor RV10 is grounded to GND, the other end of the resistor RV8 is grounded to GND, the drain of the PMOS tube QV2 is connected to MVDD, and the source of the PMOS tube QV2 is connected to the cathode of the Schottky diode DV4;

[0009] The positive electrode of the Schottky diode DV4 is connected to one end of the capacitor CV3, and both are connected to BV+3.6V. The other end of the capacitor CV3 is connected to one end of the resistor RV8, and the common end is connected to the ground GND.

[0010] BV+3.6V is electrically connected to the ADC sampling circuit.

[0011] The ADC sampling circuit includes resistors RV6 and RV9, and capacitor CV4;

[0012] One end of the resistor RV6 is connected to BV+3.6V and the other end is connected to one end of the resistor RV9;

[0013] The other end of the resistor RV9 is grounded GND, the capacitor CV4 is connected in parallel to both ends of the resistor RV9, the common end of the resistor RV6, RV9 and the capacitor CV4 is connected to the signal end Battery_1_ADC, and the signal end Battery_1_ADC is connected to the IO port of the MCU.

[0014] MHVDD is the DC power output by the AC-DC power supply, MVDD is the DC power output by the DC-DC power supply, and BV+3.6V is the positive voltage of the battery.

[0015] The utility model uses hardware to realize the automatic switching of the battery circuit under power outage, and the automatic switching is seamless, which can ensure that the MCU system can work normally without abnormal situations; hardware can also be used to realize the automatic switching of the battery circuit under power outage, which can ensure that the MCU system can work normally without abnormal situations. It has high compatibility, high efficiency, simple circuit, low cost, high sensitivity, and strong adaptability and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the circuit diagram before improvement.

[0017] Figure 2 It is a schematic diagram of the detection circuit structure of the utility model.

[0018] Figure 3 It is the basic block diagram of the battery switching of the utility model.

[0019] Figure 4 It is a schematic diagram of the ADC sampling signal structure of the utility model.

[0020] Figure 5 It is a judgment flow chart for hardware to realize automatic battery switching.

[0021] Among them, DV5 is a voltage-stabilizing diode, used to clamp the voltage; QV2 is a PMOS tube, which is turned on at a low level; DV4 is a Schottky diode with a forward conduction voltage of 1V; DV6 is a switching diode with a forward conduction voltage of 1.25V; RV7, RV8, and RV10 are chip resistors; CV3 is a chip ceramic capacitor, used for filtering and energy storage; RV6 and RV9 are chip resistors; CV4 is a chip ceramic capacitor, which filters out interference signals for ADC sampling; Battery_1_ADC is the ADC sampling signal of the battery circuit, which is connected to the IO port of the MCU, and the MCU is used to detect the ADC sampling signal of the battery. DETAILED DESCRIPTION

[0022] A battery circuit based on hardware automatic switching in this embodiment, such as Figure 1-5 As shown, the detection circuit (attached Figure 2 , 3) includes PMOS tube QV2, resistors RV7, RV8, RV10, voltage regulator diode DV5, Schottky diode DV4, switch diode DV6, capacitors CV3 and CV4. MHVDD is connected to the cathode of voltage regulator diode DV5, the anode of voltage regulator diode is connected to one end of resistor RV7, the other end of resistor RV7 is respectively connected to the anode of switch diode DV6, one end of resistor RV8, and the gate of PMOS tube, the cathode of switch diode DV6 is connected to RV10, and the cathode of switch diode is connected to DVDD, the other end of resistor RV10 is grounded to GND, the other end of resistor RV8 is grounded to GND, the drain of PMOS tube QV2 is connected to MVDD, the source of PMOS tube QV2 is connected to the cathode of Schottky diode DV4, the anode of Schottky diode DV4 is connected to one end of capacitor CV3, and both are connected to BV+3.6V, the other end of capacitor CV3 is connected to one end of resistor RV8, and the common end is connected to ground GND.

[0023] Description of ADC sampling circuit (attached Figure 3 ), resistors RV6, RV9, and capacitor CV4. One end of resistor RV6 is connected to BV+3.6V, and the other end is connected to one end of resistor RV9. The other end of resistor RV9 is grounded GND. Capacitor CV4 is connected in parallel to both ends of resistor RV9. The common end of resistors RV6, RV9, and capacitor CV4 is connected to the signal end Battery_1_ADC. The signal at this end is finally connected to the IO port of the MCU.

[0024] MHVDD is the DC power output by the AC-DC power supply, MVDD is the DC power output by the DC-DC, and BV+3.6V is the positive voltage of the battery. When the smart meter is powered on normally, the voltage regulator diode DV5 will stabilize the voltage of the gate of the PMOS tube QV2 at about 5.1V. At this time, the PMOS tube QV2 is in a cut-off state, and the battery voltage BV+3.6V cannot output MVDD, but the switching diode DV6 is turned on, which can form a loop, and the battery cannot power the MCU system. When the smart meter is powered off, the voltage of MHVDD will gradually drop. When it drops to the voltage at the gate of the PMOS tube QV2 is lower than the voltage at the MVDD, the PMOS tube QV2 starts to turn on. After the battery voltage BV+3.6V passes through the Schottky diode DV4, the voltage at the back end of the diode DV4 will decrease. This is caused by the voltage drop of the diode. When the PMOS tube QV2 is turned on, the voltage at the source and drain is turned on, and the battery voltage outputs the voltage MVDD. Use MVDD to power the MCU system to maintain some work during power outages. The ADC sampling of the battery circuit is achieved through the resistor voltage divider technology. The battery voltage BV+3.6V is divided by resistors RV6 and RV9 using the voltage divider formula. The voltage divided by RV9 is given to the chip for sampling after passing through the filter capacitor CV4. The filter capacitor for ADC sampling should be placed close to the chip pins to filter out some signals that interfere with ADC sampling and ensure the accuracy of ADC sampling.

Claims

1. A battery circuit based on hardware automatic switching, characterized in that: Including PMOS tube QV2, resistors RV7, RV8, RV10, voltage regulator diode DV5, Schottky diode DV4, switch diode DV6, capacitors CV3, CV4; MHVDD is connected to the cathode of the voltage zener diode DV5, the anode of the voltage zener diode DV5 is connected to one end of the resistor RV7, the other end of the resistor RV7 is respectively connected to the anode of the switching diode DV6, one end of the resistor RV8, and the gate of the PMOS tube QV2; The cathode of the switching diode DV6 is connected to one end of RV10, and the cathode of the switching diode DV6 is connected to DVDD, the other end of the resistor RV10 is grounded to GND, the other end of the resistor RV8 is grounded to GND, the drain of the PMOS tube QV2 is connected to MVDD, and the source of the PMOS tube QV2 is connected to the cathode of the Schottky diode DV4; The positive electrode of the Schottky diode DV4 is connected to one end of the capacitor CV3, and both are connected to BV+3.6V. The other end of the capacitor CV3 is connected to one end of the resistor RV8, and the common end is connected to the ground GND.

2. A battery circuit based on hardware automatic switching according to claim 1, characterized in that: BV+3.6V is electrically connected to the ADC sampling circuit.

3. A battery circuit based on hardware automatic switching according to claim 2, characterized in that: The ADC sampling circuit includes resistors RV6 and RV9, and capacitor CV4; One end of the resistor RV6 is connected to BV+3.6V and the other end is connected to one end of the resistor RV9; The other end of the resistor RV9 is grounded GND, the capacitor CV4 is connected in parallel to both ends of the resistor RV9, the common end of the resistor RV6, RV9 and the capacitor CV4 is connected to the signal end Battery_1_ADC, and the signal end Battery_1_ADC is connected to the IO port of the MCU.

4. A battery circuit based on hardware automatic switching according to claim 3, characterized in that: MHVDD is the DC power output by the AC-DC power supply, MVDD is the DC power output by the DC-DC power supply, and BV+3.6V is the positive voltage of the battery.

Images