mb_2024.rst 16.44 KiB

Warning

OhmPi is a participative project open to all, it requires skills in electronics and to respect the safety rules. OhmPi must be assembled in a professional context and by people competent in electronics. The OhmPi team cannot be held responsible for any material or human damage which would be associated with the use or the assembly of OHMPI. The OhmPi team cannot be held responsible if the equipment does not work after assembly.

Measurement board 2024.0.2

The 2024.0.2 measurement board has been developed to replace the 2023.0.1 measurement board. It offers superior performance compared to its predecessor. The current measurement component has not evolved and presents no major differences. However, the major upgrade is the Mikroe-2C Isolator Click module ('https://www.mikroe.com/i2c-isolator-click') . Specifically, it provides electrical isolation for the Vmn measurement set. This isolation allows for injection voltages (Vab) up to 200V

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PART A Assembly of the measurement board

Schematics

Overview of the measurement board.

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Schematic of the power supply.

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Schematic of the dsp (digital power source) power supply.

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Schematic of the Vmn signal conditioning.

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Schematic of the current injection and measurement.

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Schematic of the human-machine interface.

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Required components

Interactive BOM list

Interactive BOM list

Before starting: how to soldering

How to Solder Electronic Components <https://www.sciencebuddies.org/science-fair-projects/references/how-to-solder>

Description

Soldering various RESISTOR on the measurement board PCB

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Soldering thirteen 100 kOhm resistors
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Soldering four 330 ohm resistors
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Soldering four 4K7 ohm resistors

Soldering DIODE on the measurement board PCB

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Soldering six Diode 1N4007

Soldering SCHOTTKY DIODE on the measurement board PCB

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Soldering six Schottky Diode bat85 ou bat86
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DIP-8 socket
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Soldering DIP-18 on the pcb measurement board
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Soldering DIP-16 on the pcb measurement board
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Soldering cut socket for 3 THD
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Soldering header socket 1 row 10 positions
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Soldering header socket 1 row 8 positions
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Soldering header socket 1 row 2, 4 and 5 positions, for the 2 position cut a header socket 4 ou 5 position.

Information about light-emitting diode

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Installation of four Light-emitting diode

Information about MOSFET Metal Oxide Semiconductor Field Effect Transistor

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Soldering MOSFET ZVN4206 or ZVN4306

What is a CAPACITOR?

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Soldering 100 nF 50V tantalum capacitor
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Soldering 1u µF 50V Electrolytic capacitor, take care about polarity

Warning

In this version, we used a shunt resistor of 2 ohms, which limits the current measurement to 48 mA. If the current is higher than this value, you just have to decrease the value of the shunt resistor. Don't forget to change the shunt value in the config.py file (value associated to key 'R_shunt' in the OHMPI_CONFIG dict).

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Soldering 2 ohms shunt resistor
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Soldering IDC pins
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Six screw terminals for cable connection
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Soldering six omron G5LE relay 5 VDC
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Soldering header for raspberry 2 column 20 position