3Q triacs

Hi,everybody; two questions:

Are 3Q and Hi Comm triacs the same?
Can I drive a 3Q triac with a continuous DC signal for 15 seconds?

What do the datasheets say?

alah:
Hi,everybody; two questions:

Are 3Q and Hi Comm triacs the same?
Can I drive a 3Q triac with a continuous DC signal for 15 seconds?

Hi,

If i remember right, those kind of triacs can turn on with a negative gate signal. The only problem is that in one mode it takes more current than the other, so you have to keep an eye on the gate dissipation if using a continuous signal. That's something you can only get from the data sheet. If you post a part number we can look it up to find out.
Also, sometimes you can capacitively couple the gate to the driver so that the triac only gets a pulse of current to turn on and that's it. The circuit has to be designed right of course.
So see if you can find a data sheet or post the part number here.

Thanks and sorry for not posting before. don{t have internet at home and Ive bee reading and trying to understand. Guess 3Q, HIGH COMM and SNUBBERLES are due to trademarks. will be using
ST BTA24-800CW, 25A 800v 3Q triac. hope the attachment uploads. will be back, thanks.

alah:
Thanks and sorry for not posting before. don{t have internet at home and Ive bee reading and trying to understand. Guess 3Q, HIGH COMM and SNUBBERLES are due to trademarks. will be using
ST BTA24-800CW, 25A 800v 3Q triac. hope the attachment uploads. will be back, thanks.

Hi,

That triac looks like it will work ok with a continuous gate drive.
The gate current would be 50ma and the gate voltage less than 1.5v, so the gate power would be much less than 1 watt.
Since this is a 3Q device though that means you will need to drive it with a negative gate current, not positive, because i will have to be operated in Q2 and Q3 modes only.
That means that MT1 must be more positive than the gate to turn it on and ensure it turns on regardless what the polarity of MT2 is.
This isnt that hard to achieve though, just connect MT1 to the positive supply rail instead of ground, so that when the gate signal goes low it turns on the triac. Since the gate current should be 50ma min, with a 5v supply that means a 100 ohm series gate resistor.