[Changsha University of Science and Technology] Auxiliary isolation power supply Wang Dongmin

Topic requirements:

The bidirectional dc-dc circuit design has a rated voltage of 30V for the high-voltage side (stabilized power supply), a rated voltage of 16V for the low-voltage side (battery pack), and 5 18650 batteries in series (rated voltage of each cell is 3.2V). ① Connect S1 and S3, disconnect S2, and the output of the regulated power supply changes between 24V and 36V. Set the current closed loop to realize constant current charging of the battery pack in the range of 1A to 2A. The current control accuracy should be higher than 5%; ②Off Turn on S1, turn on S2, and set the voltage closed loop to maintain the voltage of U2 at 30±0.5V; ③ Turn on S1 and S2, turn off S3, and set the voltage closed loop to keep the output of the regulated power supply between 32V and 38V. The voltage is maintained at 30±0.5V; ④Input overvoltage protection, output overcurrent and short circuit protection.

Device: Isolated auxiliary power supply

Function description:

It can realize isolated power supply through AC and DC power supply to achieve stable and low ripple +5V, +15V, and -5V DC power supply.

AC power supply part:

   Bridge rectifier KBL606 is used for rectification input.

DC power supply part:

   The switching power supply chip XL4015 is used as the non-isolated voltage +5V and +15V regulated output, and the isolation back-end adopts

The fast-off power supply chip TPS5430 is used as a regulated output with an isolation voltage of +5V and -5V. Both chips have bottom ripple.

It has the characteristics of wide input range and high conversion efficiency.

Power isolation:

   Use Jinshengyang isolated power module as the isolation device. Jinshengyang isolated power module has long-term output short-circuit protection, bottom

Ripple noise, excellent high and low temperature characteristics, the lamp advantage is a very good choice for power isolation.

Basic part:

    Power indicator lights are added to the power input and isolation shorts to better observe the working condition of the circuit and facilitate circuit inspection.

    In the output part, multiple CONN-TH_2P interfaces are used for output. The output is simpler and more convenient, which is the basis for better scalability of the circuit.

It can meet most of the needs in power circuits.