Jon Elson wrote:
gwes wrote:
Here's a money-grubbing question from a hard-case tinkerer:

Leadin:
In order to run a 3-phase motor drive from single phase input,
the user must derate the unit by 50%. This is because the input
rectifier and filter capacitors are too small to handle the increased
peak current of a single phase feed.
You need to consider that many hobby-garage shop types buy used
VFDs on eBay for a fraction of new cost. The cost to them of derating
the drive is quite small. [...]

You have to remember that these units are designed to run in enclosed
cabinets at 50C ambient for 10 years continuously, sometimes with a
motor start every minute. That is so much more severe than what most
hobby-garage shop users put it through.

Jon

Good point. And the low-HP drives keep getting cheaper.
More than one net discount drive supplier has 1 and 2 HP 1-to-3 drives for
under $200. The box I was thinking of making would allow running 220V
units from 110 or 440 from 220, but that's very much a niche.

There are these really cute power control and PFC ICs and planar transformers
these days so it would be a lot of fun to find a good application to tinker
with....
geoff