Ignoramus17647 wrote:
I am thinking about my high capacity transistors. Supposedly they can
be used for making inverters.

What if I build something like this:

1) a 220V to 208 V transformer

fed into

2) a rectifier

fed into

3) three DC to AC inverters that have their outputs shifted by 120
degrees relative to one another.

Would that not become a phase converter (1 - 3 phase)?

i

To build your own inverter type phase converter you have to start with
building a big DC power supply. It's much harder than it looks. What would
very likely happen is that you'd go spend $40 on big power rectifiers and
as soon as you fired it up they'd go "BOOM!" and you'd be wondering why.

There is a design for an SCR-based variable frequency power supply in the
back of the old GE SCR Handbook. I did a lot of design work planning to
build one until I found out more about the failure mechanism of large SCRs
(roughly analogous to a hand grenade) and decided I didn't want them in my
house. You can pursue this if you want to and you will likely learn a great
deal but I can tell you this with great certainty: you will never cobble up
something cheaper and more robust than the inexpensive inverters you can buy
now from places like dealerselectric.com - but do keep us posted.

If you decide to press on, make sure you google on the term "snubber" because
a snubber circuit is what you'll have to design and test to keep your power
rectifiers from going boom.

GWE