[time-nuts] Re: Another reason to monitor line frequency :) - My AC measurement project & question

[Wilko Bulte]

A thought has just crossed my mind, not sure if the idea is valid or not. The idea is to re-purpose (parts of a) PLC network adapter. At the very least they can be a source of line voltage rated parts I'd think.

But the low frequency characteristics make me wonder in this context, as PLC is in the HF range?

Wilko

> On 23 Jan 2022, at 03:33, glen english LIST <glenlist at cortexrf.com.au> wrote:
> 
> hear hear.stick to galvanic isolation or better  -
> 
> On MF/SW broadcast sites for this we used optically coupled sensors.
> 
> The mains supply is simply intensity modulating an opto isolator ( a pair actually for both sides of the waveform) .. They can with stand a fair degree of overload and its likely something else will flashover first with slots in the PCB. The opto was used in a linear mode.  lots of effective R in the emitter . didnt bother with saturation prevention diode B-C because the recovery was (still) fast compared to the 50/60Hz.
> 
> -glen.
> 
>> On 23/01/2022 6:15 am, willl will wrote:
>>> On 1/21/22 7:00 PM, Robert LaJeunesse wrote:
>>> Stick with the transformer. The use of a capacitive divider is predicated
>> on the line waveform always being a sine wave. Dream on! All it takes is
>> one good spike down the line, maybe only 20-30V amplitude, and your
>> capacitive divider passes it right on to that ADC that has a much lower
>> (3.3V?) limit. Guess what goes poof?
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com -- To unsubscribe send an email to time-nuts-leave at lists.febo.com
> To unsubscribe, go to and follow the instructions there.