Thông số kĩ thuật:
The circuit relies on the internal analogue to digital converter (ADC) of the PIC Microchip Processor. The accuracy is dependant on scaling the input voltage for the ADC for all three measurements. The good news is that both the PIC's which can be used for this project have 10-Bit resolution ADC units which should work adequately in most circumstances.
In order to determine the resolution, simple to advanced mathematics can be used - I will use simple mathematics and present a basic explanation in order for you to get going on the project.
The Voltage of the PSU can be adjusted from 0 to 33V depending on the components in your circuit. The PIC can only measure voltages between 0 - 5V and represent the values measured as a 10bit binary number from 0 - 1024. In order to determine the voltage increments which can be measured one has to divide the scaled input voltage by 1024 and that equals: 33V/1024 = 32.2mV.
Similarly the current range is 0 to 3A. Which means that we can measure in 3.0/1024 = 2.9mA increments in a near perfect circuit.
Best Voltage resolution at 33.0V - 32.2mV
Best Current resolution at 3.0A - 2.9mA
In order to determine the resolution, simple to advanced mathematics can be used - I will use simple mathematics and present a basic explanation in order for you to get going on the project.
The Voltage of the PSU can be adjusted from 0 to 33V depending on the components in your circuit. The PIC can only measure voltages between 0 - 5V and represent the values measured as a 10bit binary number from 0 - 1024. In order to determine the voltage increments which can be measured one has to divide the scaled input voltage by 1024 and that equals: 33V/1024 = 32.2mV.
Similarly the current range is 0 to 3A. Which means that we can measure in 3.0/1024 = 2.9mA increments in a near perfect circuit.
Best Voltage resolution at 33.0V - 32.2mV
Best Current resolution at 3.0A - 2.9mA
Schematic:
Processor
LED PCB + Layout1 + Layout2
Processor PCB + Layout
PSU PCB + Layout
Hex file
Nguồn: http://www.electronics-lab.com/projects/mcu/008/index.html
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