Quadrac vs Alternistor - Any difference?

[Cliff Matthews]

Rolling something like an Elenco XP-625, but they used an older Quadrac sold by Teccor (who was bought by LittelFuse). I want to upgrade the part to 12amp and 600v PIV, but LittelFuse now calls them an Alternistor and puts the LED suffix on the new parts..    The new PDF says it's OK for motor loads (ie: tranformers), so is this Alternistor and LED lingo all basically new marketing wank?

[fourtytwo42]

No they are not the same part at all. The original part includes an embedded diac in the gate so to replace it if that part no longer exists you need a triac AND an external diac.

I dont know about marketing w*nk but Littlefuse have simply charecterised that part for LED lighting systems, nothing wrong with that is there ?

[Cliff Matthews]

Got it now.. and the slightly renumbered Q6012LTH1LED costs $1 more too (still don't know why they give the name alternistor when it's really just a triac. Maybe old people (like me) were thinking "triode" instead and gave it a new name.

[tautech]

Got it now.. and the slightly renumbered Q6012LTH1LED costs $1 more too (still don't know why they give the name alternistor when it's really just a triac. Maybe old people (like me) were thinking "triode" instead and gave it a new name.

Alternistor while just being a triac is a special type.
The term has been around for decades, Google it.

I first came across them in MIG welders where they're used for highly inductive loads.
Now much of this type of gear is of inverter type design their features are not called for so much.

[rsjsouza]

I really learned something new today. Thanks tautech!

[Cliff Matthews]

So an alternistor (hi-com traic) and a diac is what's needed in the schematic. I snagged an NXP appnote on 3Q triac's..