K2634 TRIAC Switch Card problem - output stays on

[pfpmeijers]

I am facing following problem with a Velleman TRIAC switch card (K2634):

Quickly switching the outputs works ok, but if I keep one of the outputs powered for some time, then I can not get the power off, even when disabling it via its corresponding input control (=> led turns off). Looks like the triac output stays "connected". Only way to reset from this state is to temporarily remove the load from the output. Then the output again listens to the input signal.

Anyone a clue about the cause and work-around?

Thanks a lot in advance, Patrick

 

[kak111]

From Vellemann discussion................
Velleman Projects • View topic - K2634 TRIAC Switch Card problem - output stays on

General triac info
**broken link removed**

Triacs are TIC206M
http://www.datasheetcatalog.org/datasheets/105/323023_DS.pdf

Triac card schema


Triacs load should be "pure" ac-current (resistive load ), so that current and voltage goes to zero when Ig = 0.

If not triac stays ON-state.

Regards KAK