CN203691031U - Uninterrupted DC power supply - Google Patents

Abstract

The utility model discloses an uninterrupted direct current power supply, which comprises a battery management unit, the battery management unit is respectively connected with a lead-acid storage battery, an AC/DC unit, a direct current output a, an LDO unit, and a CPU unit for electrical signals, and the AC/DC unit is connected with an AC The input unit is connected to the electrical signal, the CPU unit is connected to the AC/DC unit, the storage unit, the communication unit, and the DC output b electrical signal, and the LDO unit is connected to the DC output b electrical signal. It has two power sources of single-phase AC power supply and lead-acid battery. Through the power management module, the seamless switching and effective protection of the two power sources are realized. When the AC input has power, it supplies power to the load through AC/DC conversion on the one hand, and the other On the one hand, it intelligently charges the lead-acid battery; when the AC input is cut off, the lead-acid battery is immediately switched to the power supply to achieve uninterrupted power supply with DC output DC5V3A. The CPU unit monitors the working status of the DC power supply, and stores and uploads the monitoring data through communication with the superior monitor.

Description

An uninterruptible direct current power supply

technical field

The utility model belongs to the technical field of power supply devices, and relates to an uninterrupted DC power supply, in particular to an uninterrupted DC power supply with intelligent management functions and state monitoring functions.

Background technique

DC power supply has important practical applications in the field of engineering technology and measurement. It provides working power for electronic equipment for measurement and monitoring. Therefore, the high-reliability uninterrupted DC power supply plays an irreplaceable role in the normal operation of the monitoring system. However, there are potential safety hazards in the power supply of many existing monitoring systems. The common ones are that there is a time gap between the AC power supply and the battery power supply, the battery is in a floating charge state for a long time, and the power supply itself does not have sufficient protection functions.

Utility model content

The purpose of this utility model is to provide a high-performance, low-cost uninterrupted DC power supply, which is characterized by intelligent management of battery charge and discharge, under-voltage protection, short-circuit protection, remote signaling and remote control of the entire power supply working state And the storage of state quantities to solve the shortcomings of unsafe, unreliable, and uneconomical in the prior art.

The technical solution adopted by the utility model to solve the technical problem is: an uninterrupted DC power supply, including a battery management unit, the battery management unit is connected to the lead-acid battery, AC/DC unit, DC output a, LDO unit, and CPU unit respectively. Signal connection, the AC/DC unit is connected with the AC input unit with electrical signals, the CPU unit is respectively connected with the AC/DC unit, the storage unit, the communication unit, and the DC output b electrical signal, and the LDO unit is connected with the DC output b electrical signal.

The utility model is also characterized in that,

The battery management unit is completely built with discrete analog devices;

The chip used in the LDO unit is MC78L05;

The AC/DC unit uses a switching power supply;

The chip used in the CPU unit is MKE02Z64;

The storage unit uses SD card;

The communication mode used by the communication unit is a full-duplex differential 485 bus.

The beneficial effect of the utility model is that the utility model adopts single-phase AC voltage and dual-circuit power supply of lead-acid battery, adopts the intelligent management mode combining CPU and power management unit, effectively improves the reliability and economy of the DC power supply, double Seamlessly switch between switching power supplies.

Description of drawings

Fig. 1 is a block diagram of the principle structure of the utility model uninterrupted DC power supply;

Fig. 2 is the circuit schematic diagram of the AC/DC unit in the uninterruptible DC power supply of the utility model;

Fig. 3 is the circuit schematic diagram of the battery management unit in the uninterruptible DC power supply of the utility model;

Fig. 4 is a schematic circuit diagram of the LDO unit in the uninterrupted DC power supply of the utility model.

In the figure, 1. AC input unit, 2. DC output a, 3. DC output b, 4. AC/DC unit, 5. Lead-acid battery, 6. Battery management unit, 7. LDO unit, 8. CPU unit, 9. Communication unit, 10. Storage unit.

Detailed ways

Below in conjunction with specific embodiment the utility model is described in further detail:

The utility model provides an uninterrupted DC power supply, as shown in Figure 1, which is composed of an AC input unit 1, a DC output a2, a DC output b3, an AC/DC unit 4, a lead-acid battery 5, a power management unit 6, and an LDO unit 7. It is composed of CPU unit 8, communication unit 9 and storage unit 10, in which the battery management unit 6 is respectively connected to the lead-acid battery 5, AC/DC unit 4, DC output a2, LDO unit 7, and CPU unit 8 for electrical signals, and the AC The input unit 1 is electrically connected to the AC/DC unit 4, the CPU unit 8 is respectively connected to the AC/DC unit 4, the storage unit 10, the communication unit 9, and the DC output b3 electrical signal, and the LDO unit 7 is connected to the DC output b3 electrical signal .

1. AC input unit

As shown in Figure 1, the AC input unit 1 is the interface for injecting AC power into the power supply, and uses strong insulation wiring segments. The voltage range of the input unit is AC85V~265V.

2. DC output a

As shown in Figure 1, the DC output a2 is the first group of the two DC outputs of the UPS. The output voltage of this output port is DC14V1A, which can be easily expanded to 12V, 9V, 5V, and 3.3V voltage levels.

3. DC output b

As shown in Figure 1, the DC output b3 is the second group of the two DC outputs of the uninterruptible power supply. The output voltage of this output port is DC5V3A, which is a standard microcontroller power supply interface.

4. Lead-acid battery

As shown in Fig. 1, the lead-acid battery 5 in the utility model is a 12V5AH～12V8AH maintenance-free lead-acid battery, and the charging method adopts a constant current and constant voltage charging method, which has a battery activation function.

5. CPU unit

As shown in Figure 1, CPU unit 8 takes MKE02Z64 as the core to receive AC power-down remote signaling and undervoltage alarm remote signaling respectively, communicates with the upper-level controller through communication unit 9, uploads monitoring signals, and obtains instructions from the upper-level unit. Judging whether to issue a battery activation control command and whether to read the data in the storage unit 10, the power supply of the CPU unit 8 is provided by the DC output b3, and the purpose of designing the CPU unit here is to make it easier to expand later.

6. Communication unit

As shown in FIG. 1 , the communication unit 9 is connected to the CPU unit 8 and is responsible for two-way communication between the CPU unit 8 and the upper-level controller. The communication unit 9 is a full-duplex differential 485 communication composed of two SP3485s, which has the characteristics of strong anti-interference ability and stable performance.

7. Storage unit

As shown in Fig. 1, the storage unit 10 is connected to the CPU unit 8, and stores the status monitoring data according to the instructions of the CPU for troubleshooting. The storage unit 10 uses an SD card, which is a fast flash memory unit with small volume and high capacity.

8. AC/DC unit

As shown in Figure 2, the AC/DC unit 4 adopts a flyback switching power supply based on TOP266EG as the core, and its function is to convert AC voltage into DC voltage. The input of the power supply is connected to the AC input unit, and after rectification and filtering, it is added to the primary side of the flyback transformer and the integrated MOSFET inside U2. When the AC voltage is powered on, U2 starts to oscillate, and the feedback DC output voltage signal controls the on-off duty cycle of the MOSFET inside U2. During the off-time of the MOSFET, the energy is transferred to the secondary side through the flyback transformer. A stable DC voltage is obtained after output rectification and filtering. The input voltage range of this unit is AC85V～265V, the output voltage is DC14V3A, one part supplies power for the lead-acid battery, and the other part directly supplies power for the load. A working indicator light and an AC power-off remote signaling output signal are added to the output end, which is realized through U3, and the remote signaling signal is output to the CPU.

9. Power management unit

As shown in Figure 3, the power management unit 6 is built by purely discrete analog devices, 14V+ and 14V- are connected to the output of the AC/DC unit 4, Vbat+ and Vbat- are respectively connected to the input positive and negative poles of the lead-acid battery, and output Vpow+, Vpow - Connected to the LDO unit, the functions realized are:

One is seamless switching between AC power supply and battery power supply. When the AC power is on, the upper tube of D1 is turned on, and the AC supplies power to the load, and at the same time judges whether to charge according to the voltage at both ends of the battery; when the AC power is off, the lower tube of Q2 and D1 is turned on, and the battery supplies power to the load. The switching delay is only tens of nanoseconds.

The second is the battery charging function. It is composed of R1, R2, Q1, Q2, Q3, Q4, and Q6. When the voltage at both ends of the battery is very low, the CPU will control Q1 to cut off according to the remote control or on-site "activation" command, and the system will charge the battery in the way of trickle charging. Charging to achieve the activation effect; when the battery voltage reaches a certain value, Q1 is turned on, and the system will charge the battery with a constant current to improve charging efficiency; when the battery terminal voltage is higher, the charging will gradually decrease until it ends.

The third is the protection function. Low-voltage alarm, composed of U1, D4, R9, R10, and Q5, the low-voltage alarm generates a remote signal and sends it to the CPU unit 8; under-voltage protection, mainly composed of D5, D6, Q2, and Q7, the battery terminal voltage is lower than the set value When, Q2 cuts off, and the battery stops discharging; the protection function, when the two ends of the battery are short-circuited, the power management unit 6 will not be burned.

10. LDO unit

As shown in Figure 4, the LDO unit 7 is composed of U2, C3, and C4. The output of the battery management unit 6 is connected to the input 7 of the LDO unit. After the transformation of U2, a stable 5V3A DC output is output.

Claims (7)

1. An uninterruptible DC power supply, characterized in that it includes a battery management unit (6), the battery management unit (6) is connected to a lead-acid battery (5), an AC/DC unit (4), and a DC output a (2) respectively , LDO unit (7), CPU unit (8) for electrical signal connection, AC/DC unit (4) for electrical signal connection with AC input unit (1), CPU unit (8) for AC/DC unit (4), storage The unit (10), the communication unit (9), and the electrical signal of the DC output b (3) are connected, and the LDO unit (7) is connected with the electrical signal of the DC output b (3). 2. An uninterruptible DC power supply according to claim 1, characterized in that, the battery management unit (6) is constructed by using discrete analog devices. 3. An uninterruptible DC power supply according to claim 1, characterized in that the chip used in the LDO unit (7) is MC78L05. 4. An uninterruptible DC power supply according to claim 1, characterized in that the AC/DC unit (4) uses a switching power supply. 5. An uninterruptible DC power supply according to claim 1, characterized in that the chip used by the CPU unit (8) is MKE02Z64. 6. An uninterruptible DC power supply according to claim 1, characterized in that, the storage unit (10) uses an SD card. 7. An uninterruptible DC power supply according to claim 1, characterized in that, the communication mode used by the communication unit (9) is a full-duplex differential 485 bus.

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