Project

# Title Team Members TA Documents Sponsor
73 Isolated Current Sensor (Pitched Project)
Akshat Dhavala
Rohan Chaturvedula
Sean Geary
Matthew Qi design_document2.pdf
design_document1.pdf
final_paper1.pdf
other1.pdf
photo1.jpg
photo2.jpeg
presentation1.pdf
proposal2.pdf
proposal1.pdf
video
# Isolated Current Sensor

Project Sponsor:
Jason Paximadas (jop2)

Team Members:

- Rohan Chaturvedula (rohanvc2)
- Akshat Dhavala (dhavala2)
- Sean Geary (smgeary2)

# Problem:

In power electronics research, we often need to equip microcontrollers with the ability to accurately sense a high current signal. The result is inefficient use of time and effort to create a new circuit that will manually test the current.

# Solution:

We would like to create an isolated current sensor that has the ability to read the current in circuits. This product should be universally usable and have reading accuracy of +/- 1%. This device must monitor its output in real time and convey that information to the user. Additionally, it must be able to handle three simultaneous current inputs without any drop in quality.

# Solution Components

The system will consist of a microcontroller, an analog to digital converter, a Hall-effect current detecting IC, a power source, and an SPI interface to communicate the results.

## Subsystem 1: Hall Effect Current Detecting IC

We will utilize the Texas Instruments TMCS1100, a galvanically isolated Hall-effect current sensing IC to accurately measure the current. This chip also comes equipped with a zero current output voltage reference. We will be setting baseline standards for each of the three chips by feeding in known currents, reading the outputs of the chip, and finding the correlation between the input current and the output voltage.

https://www.ti.com/product/TMCS1100/part-details/TMCS1100A1QDR?utm_source=google&utm_medium=cpc&utm_campaign=ocb-tistore-promo-asc_opn_en-cpc-storeic-google-wwe&utm_content=Device&ds_k=TMCS1100A1QDR&DCM=yes&gclid=Cj0KCQiA2-2eBhClARIsAGLQ2RmHtTJoKDjLic_rZNSalLk1ww2lNuN3ouapPPh9FsiSocdq_zuid2MaAscFEALw_wcB&gclsrc=aw.ds

## Subsystem 2: ADC

The ADC will take the resulting analog voltage signal from the Hall-effect sensor, convert it into a digital signal, and pass that through an anti-aliasing filter and a low pass filter before giving out the final digital output . We will be using a chip that uses the SPI interface, provides a sampling frequency that is at least above 100 kHz, and has 3 or more inputs so that simultaneous conversion can take place. We are currently considering various chips that fulfill this criteria, including the ADS9817 ( which provides 8 separate channels and a max sampling frequency of 8 MHz) ,ADC128S102-SEP ( which also provides 8 separate channels and a max sampling frequency of 1 MHz, and ADS7067 ( which provides 8 separate channels and a max sampling frequency of 800 kHz).

https://www.ti.com/product/ADS9817
https://www.ti.com/product/ADS7067
https://www.ti.com/product/ADC128S102-SEP


## Subsystem 3: Microcontroller

Our system will have an ATtiny85-20SU microcontroller that will take data from the current detector, figure out the current reading, then send the reading out via SPI.

## Subsystem 4: Interface

In order to see the readings we collect, we will utilize SPI to connect to a digital output that will show us this information.

## Subsystem 5: Power

For the device to be universal, we will need to use our own power source to avoid interference with the other device that is being tested. Our device will use a battery to power the components.

# Criterion for Success

- +/- 1% Reading Accuracy
- 50 KHz Bandwidth
- Digital Output
- Operate within +/- 10A
- Achieve simultaneous current measurement

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