Hello you guys, thank you for accepting me here, right now I'm making a tool to dry the plastic filament, the unfinished part is the dimmer with a triac because MT 1 and MT 2 are on fire, like this has happened for the third time, then the input section exploded three times that caused the electricity at my house went out.

But this circuit works if I use breadboard but not veroboard, and this dimmer I combine with 555 timer IC (circuit diagram in figure 3 and figure 4b, http://www.nutsvolts.com/magazine/article/using-the- 555-timer-ic-in-special-or-unusual-circuits). I do not know what caused it, hope you guys help me, thanks.

 

Veroboard is not suitable for high voltages due to the close spacing of the pads.

Les.

 

Looks like those solder blobs are pretty close together and may have shorted at one (or three) times.

When I build AC mains circuit on that pad-per-hole veroboard I remove the un-needed pads to allow more creepage distance between the pads conducting the AC. With transistors and triacs I spread out the leads -in the TO-220 package and similar packages I have the middle lead not in line with the other two, like in the picture below -that also increases the distance between the conductors.

Maybe those techniques -removing un-needed pads in the high voltage area and bend the center lead away from the other two will give you enough creepage distance to avoid the fires.

 

See

 

Sorry if my words are not technical. Well I'll try to make the distance a bit more tenuous especially in the triac part, I'll get back to you as soon as possible. Can I use all of its components again or should a new one?

Load, which I use is a heating element of 300W hair dryer.

 

If you don't have new ones on hand I suggest trying the old components first, they are probably good.

 

I try to take all the suggestions from all of you and I say thank you, including the schematic even though I do not have triac L6004L8 and still use BT137. Then remove the un-needed pads and now it's not fire out in triac or anywhere else, and I'm happy. Any other suggestions I need to do with this circuit?

 

Beautiful work