Don't forget to check the SCR because this is another possibility: Thyristor latch-on if the voltage (A to K) approaches the maximum of the SCR.

 

Which new parts did you fit when your trouble started?

Wherever you source T2 from, make sure that the LV and HV windings are totally separated from each other. Secondly, all windings should be layer-wound with proper insulation between layers. Thirdly, the coil sides are potential break-over points, either between different layers or between a layer and the core material, therefore enough gap should be allowed during the construction of the transformer. Last, but not least, it should be heated in a furnace, then dipped in insulating varnish, removed after impregnation and baked until dry and hard.

The current is not directly responsible for the damage done to T2, but rather the associated high voltage spikes that cause a breakdown in insulation, effectively shorting out HV turns, rendering them useless thereafter. This is why I emphasize the importance of a carefully designed and constructed transformer. (Do-it-yourself if you have the time).

Some fence charger manufacturers sell spares for their products and perhaps you should try to get hold of transformers this way.

Good luck!

did not want not really get into building it myself--time shortage here. The one (t2) I have been using is from a fencer company. Guess better check another place. At least that will give me something to check against. If they are the same, then look elsewhere.

 

I would not have believed that something so small could be so humbling. With your help on this thread, I have been able to understand these fence chargers to a degree that allows me to fix them in short order. However, I have run upon two broken boxes that I cannot figure it out. So I am back here again asking for you help.

The Problem: There is only 120VDC coursing throughout the entire board (when everything is hooked up). Should be 356VDC across both A(s) and both B(s). It also should be 250 VAC across both A(s). If I remove c3 caps and t2 trans, I do get 356 VDC when checking across points A and B, including the 250VAC. (see schematic provided). I have replaced all the resistors (R1 thru R5) to their individual specs. I have replaced the c2 Cap with a new type 47uf 100V (47uf 50v was the old one). The C1 I have replace with a polycarbonate type capacitor (2.5uf, 680VDC) instead of the electrolytic (can type cbb65A) caps. I have replaced the c3 (all 40uf) with multiple types of capacitors with the same result. T2 trans reads 0 ohms at the primary and 256 at the secondary. This is what a new one T2 reads. I have replaced the Diac, (HT32) and the Thyristor mcr265-11. The T1 trans I have changed out with similar results when C3 and T2 are connected to the circuit.
The only items I have not changed is the four D1 Diodes and they all tested between 500-900 when removed from board.
Has anybody got any ideas? There almost has to be a simple explanation.



Have a nice day:>)

Bladerunner\

 

Here is the schematic. Had too many words in the 1st post.

Have a nice day:>)
Bladerunner

 

here is the schematic from the fist post.

have a nice day :>)
Bladerunner

 

here is the schematic from the fist post.

have a nice day :>)
Bladerunner

Lets try this again

Have a nice day:>)
Bladerunner