cw32f030c8t6 Geostationary Training Camp Voltage and Current Meter

Circuit Description
1. Power Supply Circuit
This project uses an LDO as the power supply. Considering that most voltmeter products are used in industrial scenarios with 24V or 36V power supplies, the SE8550K2 with a maximum input voltage of up to 40V was selected as the power supply. The main reason for not using a DC-DC step-down circuit to handle the large voltage difference is to avoid introducing DC-DC ripple interference during the design process, and the secondary reason is to reduce project costs.
2. Voltage Sampling Circuit
The voltage divider resistors in this project are designed to be 220K+10K, therefore the voltage division ratio is 22:1 (ADC_IN11).
3. Current Sampling Circuit:
The sampling current designed for this project is 3A. The selected sampling resistor (R0) is 100mΩ.
The following aspects need to be considered when selecting the sampling resistor:
1. The maximum value of the pre-designed measurement current, which is 3A in this project
. 2. The voltage difference caused by the current sensing resistor; it is generally not recommended to exceed 0.5V
. 3. The power consumption of the current sensing resistor; a suitable package should be selected based on this parameter. This project takes into account 4. The power consumption (temperature) issue at high current, and a 1W metal wire-wound resistor was selected.
5. The voltage amplification factor across the current sensing resistor: No operational amplifier was used to build the amplification circuit in this project, therefore the factor is 1.
4. Display Circuit:
The display circuit uses two common-anode digital tubes to display the current and voltage values, and a 300-ohm current-limiting resistor is used for current limiting.
Physical Diagram,
Schematic Diagram
, PCB
Diagram,
Data Link (Baidu Cloud)
: https://pan.baidu.com/s/1vjG3_UVXLNTWYftwhAdhMA?pwd=jpz3
Extraction Code: jpz3