Guru
Joined: 13/10/2014
Location: AustraliaPosts: 2260
| Posted: 01:25am 01 Aug 2026 |
FYI: I had been looking at the AC output on the test inverter without an AC output filter. Now, with the slightest 20khz fluff removed from the peaks, this AC sine wave is as perfect as my precision sine wave oscillator and analogue osc.
I'm not trying to embellish this, it's visually perfect, this is not what I would expect to see from any high power Inverter.
Using a Rigol MSO5354 In DOT mode, which gives higher fine detail resolution, and looking at single and multiple sine waves for timing precision with respect to 0, 90, 180, 360 deg zero crossing and peak envelope symmetry, it looks absolutely perfect, with not a single wobble or imperfection of the slope or zero crossing.
Would be interesting to know what others find if you get around to looking at it, also latest version uploaded.
I just tested a small 2.5kW / 5kW peak, HF pure sine Inverter, 1.7% THD at idle, sine wave has small wobbles on both sides above and below zero crossing, and 15 small harmonics, it would never in a million years be mistaken for a sine-wave generated by a quality piece of workshop test equipment, the WG Inverter output does, and currently indicating 0.4% THD.
DOT mode capture always looses intensity, these are with the inverter completely unloaded, and NO bandwidth limiting (350MHz).
Below:
I realised that all my uploaded captures have been with a small resistive load, or under higher testing loads. Below is the unloaded, unmodified code on the test Inverter, most unloaded AC outputs posts from most builds in the past have had wobbles, some have a lot, but look reasonable with a few hundred watts of resistive load applied, even this last unloaded capture still looks good to me, it was basically thought of as good as you can get, but it's not as clean as the first two above with the slightly modified sine array.
We normally put this wobbles down to choke interactions and/or layout, wiring etc.
FYI: Test inverter had a total of 10,000uf filter caps.
Edited 2026-08-02 09:14 by KeepIS