Re: Recent s.s.t.c. work

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Conner <steve@xxxxxxxxxxxx>

> With a
> feedback circuit dependent on primary current to
> operate, it's a
> little tough to do otherwise.

That's another reason why I chose to build my driver
around a PLL. If the feedback signal is missing or
bad, it runs as a plain oscillator and still drives
the IGBTs at a sensible frequency. That means I can
check out gate signals etc. with the main DC bus
turned off, and then bring the DC bus voltage up
slowly and verify that it locks on.

To test your circuit, you can of course substitute the
current transformer signal with a sine wave from a
function generator. But that will only get you so far.

Steve Conner