Electric Fence Zapper

[David HK]

Owing to my lack of knowledge and training, maybe Oztules could satisfy my curiosity on the following:-

The PCB has a total of 14 Triacs divided into two banks of seven each with its own diac. The bank 'on-line' is determined by a jumper. The logic being that if one set of Triacs fails then another set is ready to go. Would it work?


Dave

[rossw]

I think it would depend somewhat on the failure mode of the original bank of SCRs.

If they failed short circuit, then no - because they'll just short out the "spare" bank too.
If they failed open circuit, then WHY? Whatever made them fail MAY have taken out the "spare" bank too.

It's a long time since I've worked with those devices, but I believe you can "turn them on" with a rapid DV/DT, which COULD see the second bank triggering simply BECAUSE the first bank triggered.

Finally, if you're going to put 14 on the board, why not just stack 'em permanently? Wouldn't that make it just about indestructable??

[David HK]

Your're quite right on all accounts Ross, my curiosity is satisfied.

Dave

[frank]

Hello.My work.Ty

[frank]

Hello.I did hv coil and make 5kV. little ,small.thank you.Out as yours?thank

[frank]

Hello.HV coil yours out what voltage?ty(scuze)

[oztules]

Using modified microwave transformers, and 50uf@600v trigger voltage... about 14000v unloaded is the best I have done
normally don't try for that much.

Loaded for 500 ohm load, about 8000v
9 turns of 2 in hand 1.8mm primary, 260 turns 1mm wire secondary.

Every one I make is different though.


...............oztules

[frank]

Thank you.

[frank]

Thank you.

Hello. Two such coils are connected? Parallel? Ty

[oztules]

In parallel. This lowers the resistance. The lower the primary resistance the higher the out voltage can be.

Lower resistance will allow faster capacitor discharge, faster changing field, more voltage generated in the output

oztules

[frank]

Ok....Thank you ''oztules"

[frank]

Hello!We found a problem transformer winding mayor HV.Please tell me which of the three modes of winding drawn in the picture below correct? Picture 3(bifilar parallel-counter wound) I understood that mod.It's right?

[oztules]

I use bifilar parallel/



...........oztules

[frank]

Thank you ''oztules"

[st8nme]

I have tried  to use microwave transformer the laziest way-just removed secondary winding and wound 9  turns.Do not know the number of turns of the primary winding,but loaded with 400 ohm it gives aprox 6000V.
I know it is unreliable,but is working for a week.