Author Topic: Power Meter for Variac  (Read 2271 times)

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Online ledtester

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Re: Power Meter for Variac
« Reply #50 on: April 16, 2021, 09:06:11 pm »
The Peacefair units use the V98XX series of energy metering SoC chips:

https://youtu.be/G0AlH3vtT0k?t=9m12s

http://www.vangotech.com/int/uploadpic/157234475389.pdf

Update: In section 18.3 (physical page 275) of the V98XX datasheet there are some tables showing the update and settle times of the metering registers along with this note:

Quote
... In 60Hz power grid, the time for updating and settling is 1.2 times of that for 50Hz power grid. ...
« Last Edit: April 16, 2021, 09:36:28 pm by ledtester »
 

Online coppice

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Re: Power Meter for Variac
« Reply #51 on: April 16, 2021, 09:16:08 pm »
I also find the chinese power meters have very long averaging time in firmware, it takes a few seconds to get a settled reading with a constant load. They aren't useful for fast response unless you communicate directly with the IC.
I wonder if that's because they use cheap/slow parts and a low sample rate?
Its because they use the cheap, but quite accurate, devices made for the utility energy meter market. That market cares about accuracy over a wide dynamic range, but not about the update rate.
 


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