20-10-2017, 08:31 AM
No, because as my reply explained, the meter is seeing 50Hz. How can it see anything else - the mains is 50Hz!
There might well be an amount of high-frequency interference riding on the mains as a result of the transformer, but that will be very small compared to the 230V 50Hz input. The transformer should have filtering at the input, designed to keep the switching noise inside the unit.
As explained, there might be PFC (power factor correction), which will make the current draw more sinusoidal, which - if anything - will improve the accuracy of the current readings. Either way, the only unknown is the exact shape of the current waveform - but it will be predominately 50Hz.
PFC is increasingly important today, as without it, power supplies only draw current at the peaks of the AC voltage, and these peaks are many times the average current delivered to the load - this causes all sorts of problems for supply companies, etc, so PFC - which aims to make the current draw more sinusoidal so the device looks like a simple resistive load - is seen increasingly often in really quite small power supplies.
There might well be an amount of high-frequency interference riding on the mains as a result of the transformer, but that will be very small compared to the 230V 50Hz input. The transformer should have filtering at the input, designed to keep the switching noise inside the unit.
As explained, there might be PFC (power factor correction), which will make the current draw more sinusoidal, which - if anything - will improve the accuracy of the current readings. Either way, the only unknown is the exact shape of the current waveform - but it will be predominately 50Hz.
PFC is increasingly important today, as without it, power supplies only draw current at the peaks of the AC voltage, and these peaks are many times the average current delivered to the load - this causes all sorts of problems for supply companies, etc, so PFC - which aims to make the current draw more sinusoidal so the device looks like a simple resistive load - is seen increasingly often in really quite small power supplies.
