Triacs, was Re: trigger gap

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Some of the "triacs" used in consumer dimmers (e.g. from Lutron, etc.) use
a device called a Quadrac, which is essentially the triac and diac in one
package (I would imagine that it's a monolithic device, not two dice in a
package, but you never know..)

Teccor is the big maker of Quadracs (as well as triacs..)
http://www.teccor-dot-com/web/PDF%20Files/Power/E3%20Quadrac.pdf

The Q4015L5 is a straight TRIAC
http://www.teccor-dot-com/web/PDF%20Files/Power/E2%20Triac.pdf  
The Teccor part number breaks down as 
Q 40 15 L5 >>>  Q= triac; 40 = 400V; 15 = 15A; L5 = TO220, isolated tab

It looks like the Q4015LT or ..LTH would be the quadrac form... The H is a
version that has bigger dv/dt (30 vs 4 V/uS)

> 
> I would definately change out the original Lutron triac. Also, ensure you
> get the Lutron brand to
> ensure consistency of design. For example, the Ace Hardware brand doesn't
> include the diac which if
> used, should be added to the circuit to ensure consistent triggering (you
> don't want a bunch of
> misfires with a wide gap spacing - can be hazardous to the cap and NST).
> 
> Also, the the triac MAC223AB on page 2 of the pdf should be MAC223A8.
> Here's the triac I've used:
> 
> Industry Number  : Q4015L5
> NTE Device Number: NTE56020
> TRIAC-400V,25AMP,TO-220 ISOL
>