I have never understood why the neutral current is described as harmonics, in a practical sense the neutral on a dimmer has a fundamental frequency of 150hz [180hz US] with harmonics running off that, if you put a frequency meter on any dimmers neutral this is what you read.In any case we should change the name, there's nothing harmonious about them.
Interesting article. It sounds like this was an in-house distribution transformer, so there was access to it for removing/disabling the filter. The problem I see is if utilities start using blocking filters in their 13k site transformers. (You know how they are about non-liner draws!) Imagine calling them up and trying to get them to take it out! You'll be lucky if you get them to send anyone out, and that will probably be a guy with a light bulb who say, "Yup.. It Lights.. You got power. Bye!"
Keep in mind that much of the cost difference is from the tiny, speciallized computers that are required to run these modules.
No they aren't very powerful, no they aren't special, but no...there aren't many being made.
The article was a good read, I applaud your continued good work.
From a design standpoint of view, the IGBT vs SCR/Triac/SSR does not justify the current cost difference. It is more of a software issue as you need to produce a series of on/off times as compared to simply an "on" for phase chopping, or an "off" for reverse phase dimmers. sine-wave dimmers also do not require the large filter chokes that are currently used, although a smaller choke is still required as to keep the FCC happy!
Cost, I feel will be governed more by market conditions then parts requirements.
WOW! I just looked at it Lite-Puter get Sine Wave Patent
Looks like we have be Shanghaied by Shanghai !
The patent looks so generalized I can't believe they got it!
This may actually be a very bad thing as it is a US patent and may inhibit any US companies from developing it. The text is so general that they could put a claim against anyone who builds or has built a sine wave dimmer since 2006:
Quote from site:
DEAR ALL:
Lite-Puter get United States Patent: Sine Wave Light-Adjusting Apparatus on February 2, 2008.
Unite State Patent Certificate No. :7329996.
The period of validity: From May 4, 2006 to July 26, 2026
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