Connecting an ADC to USB port

Thread Starter


Joined Jan 5, 2023
I have a current transformer(Rogosci coil) that has a range of 0-5V DC. My PC has a USB 3.0 port.
The coil will need to be connected to an ADC, which has a parallel output, which needs to be connected to the USB port.
I will write the software to process the data.
Any idea on how to proceed?


Joined Jan 15, 2015
I have a current transformer(Rogosci coil) that has a range of 0-5V DC. My PC has a USB 3.0 port.
A CT (Current Transformer) is an AC device. This would go much better if you can provide a link to exactly what you have. There are CTs which will output a DC voltage proportional to the AC current measured. These are more than just a CT. The latter are often called a Current Transducer and they look like this. How to interface exactly what you have to what you want to do starts with exactly what you have? Next your choice of ADC will determine both the accuracy and resolution of your measurements. Finally with AC current transducers there are Average RMS Current Transducers and Transmitters as well as True RMS Current Transducers depending on the AC current you want to measure.

Just for example if I have a 10 bit ADC with a 0 to 5 volt input the best resolution will be 5 / 1024 = 0.00488 volt or about 4.88 mV. Using a 0 to 50 Amp AC current transducer becomes 0 to 50 AAC = 0 to 5.0 VDC or 5.0 / 50.0 = 0.1 volt per amp. You write your code accordingly. Today 12 bit ADCs are low cost and abundant.

Anyway you choose an ADC based on what you want. Since you have a 0 to 5 VDC signal you may want to consider an ADC with a 0 to 5 VDC input range. That or if you get a 3.3 volt input range dividing your AC transducer out down and scaling in your code.



Joined Oct 28, 2019
A Rogowski coil is a current transformer. A Rogowski coil outputs a voltage proportional to the current, whereas a traditional current transformer outputs a current proportional to the input current
Rogowski coils are very accurate and have a very large frequency response, which is why they are used mostly in measuring circuits. (not power circuits)
As with all current transformers used for AC, the Rogowski coil output needs to be rectified and then measured (usually by an RMS calculation). You cant just use diode rectification as you lose the diode threshold voltage, so an op amp based rectifier before your ADC is required.


Joined Aug 27, 2009
Another possibility if you're writing custom software and building hardware for USB interfacing.
The MCP2210 SPI Slave Motherboard is designed to work together with the MCP2210 Breakout Board (ADM00419). The motherboard provides the test-points required for measurements. It also contains the following SPI slave devices: • MCP23S08 – 8-bit I/O expander • MCP3204 – 4 channel, 12-bit ADC • 25LC02 – 2 kbit EEPROM • TC77 – Temperature sensor All devices are SPI slaves, controlled by the MCP2210. Windows®-based PC software is used to evaluate/demonstrate the MCP2210 as a USB-to-SPI (Master) device. It allows I/O control and custom device configuration.