Re: Triac as gap replacement

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Stephen Conner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

At 20:12 18/06/03 -0600, you wrote:
>Original poster: "K. C. Herrick by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <kchdlh-at-juno-dot-com>
>
>Have any of you looked into triacs having something like these
>capabilities?

As far as I know, we looked into triacs and SCRs for the OLTC, and rejected 
them because they take too long to turn on. If you try and turn on a triac 
with more than a certain di/dt, something horrible happens. For one 25A 
triac that I looked at, the maximum di/dt was 50A/us.

Also, triacs have a pretty high forward voltage drop, at least a couple of 
volts. This is because they have several P-N junctions in series, none of 
which can saturate :(

The bottom line (I think) is that IGBTs can kick their butts any day. Have 
a look at a sample triac datasheet to see:

http://us.st-dot-com/stonline/books/pdf/docs/7470.pdf

Steve C.