CT to measure AC Voltage and frequency


My plan is to make a CT meter that requires using a CT to measure AC Voltages and frequency of the main supply..
I know there are couple of tutorials available that fits the purpose but I need a response time of max 50ms. i.e. the CT meter should be capable of taking the sample every 50ms.
Does it require any special CT? would a mcu based CT meter capable to take a sample every 50ms.
Any suggestion on CTs and other parts can help.


please explain what is a "CT" in this case? C)omputer T)homography ??

Maybe Current Transducer ? :thinking:

Current transformer

that makes sense. Well than it depends on the inductivity of the coil.
As a very rough estimation out of my stomac I estimate at 50 ms inductivity is not the main factor
it just depends on the sampling-speed of your ADC. So you should use something with SPI-interface or high-speed internal ADCs like a teensy 4.0



best regards Stefan

Did you have a particular Current Transformer in mind?

the CT meter should be capable of taking the sample every 50ms.

The CT sensor output is used to measure current only, and is instantaneous. The Arduino sample frequency is something you choose. Excellent tutorials for Arduino here.

I am planning to use sct-013 for current and zmpt101b module for voltage and frequency monitoring.. not sure if it can deliver the current ratings every 50ms..

Thanks, the tutorial was pretty good.. I will implement this to check if it can monitor the parameters every 50ms

I am thinking of using ESP32.. Would this be enough?

Any modern MCU can do that. 50 ms is an eternity.

the internal adc of the ESP32 is near to 0,0V and near to 3,3V non-linear.
strange but is so.

Recently I used the external 4 channel 16bit ADC ADS1115 it has a i2C-interface
maximum sampling rate is 860 samples per second.
best regards Stefan