Guru
Joined: 13/10/2014
Location: AustraliaPosts: 1770
| Posted: 06:24am 04 Jun 2023 |
I finally have my Peak DC current Analogue meter calibrated. I made a precision peak detector [virtually instant attack time and slow release] with a dual setting for release time. The hard part was calibrating it to almost 600A.
The meter I used was one of the two I saved in my vintage parts bin. Made by SIFAM in England, it still has the written test data and serial numbers on the sides of each.
Originally marked as kW meters, I did my usual of removing the scale plate once I had enough accurate ref points, scan it in, photo shop a new scale, fit it over scale plate and done. I even include all the existing ID and type info on the new scale, basically it looks original. Made even easier as these old meters are like new.
Dam it's scary seeing the pointer kiss just under 600 amps starting the Comp. It's just brilliant to be able to see at a glance the current that the FETS and Toriod are using to produce the Power to these big startup loads.
One update on the Noise and waveforms:
Since removing the crap Fuse holder and meticulously going over every connection to the Toriod, chokes and driver board, the startup currents has gone up slightly, I though it might drop, but the startup is even more unbelievable with the ancient 3HP compressor.
Today when standing in front of the inverter filming the Meter face during calibration [don't ask], I had to ask my wife to start the compressor, "when she had just done that", I heard nothing from the inverter and the spin up of the compressor was so dam fast that it didn't ever register to my ears, I repeated it a few times during the day just to check if I'd been daydreaming, the results were exactly the same.
This inverter sounds so freaking Strong, and every indication of the DSO and other measuring equipment I have connected agree with that feeling.
This really is something that I though was unattainable for a home built inverter, I'm sure others have the same feeling when they get one running, especially considering the major components are salvaged from junked equipment and the rest handmade by us.
It just seems so effortless now for an input surge of 27.3kW [581A peak] which includes 1.5kW of additional running loads at the time.
Yes, I know
rambling on.. but it sure is fun when things work 
One on the left is with my new scale.
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Edited 2023-06-04 19:34 by KeepIS