Hi there.
I am very new on the eeblog forum
.
So I got an electric fence (for cattle) that I am trying to repair.
The advertised specs are: 3Joules, 10kV.
Though I did not checked it, it was able to make quite a spark.
So it started to be really about weeks ago, it would not even show any sign
of voltage onto the purposely designed voltmeter (basicaly I think this is just a bunch of
lamp with different resistance on them: I will call the ACME tester).
So after some test with it, I concluded it was the pulse coil that was deffective.
So I order a transformator (pulse transformator) core from ebay, received it.
I coiled it as at least like the former one (ratio of 10/1).
I tested with 10/1 nothing (onto the ACME tester) but it was able to make a small spark.
So I decided to go for 20/1, then I can see the lamps flashing onto the ACME tester.
After discussion with the user, we decided to ramp up to 30/1. Still working onto the ACME tester.
So I put some tips on the transformer (to make final installation).
I connected again the transformer with the load but I thought I plug correctly the transformer's primary (I DID NOT...)
I heard a tick sound.
So after some trouble shooting I concluded that the bt139-600 should be fried.
I bought 5 from ebay (along with some diodes (20x) em516 and a condensator 400vac 1µF).
1st try: Installed one the board, fried (not when connecting with the old tranformer the new one, with 30/1 ratio)
2nd try: Installed one the board, fried (not when connecting with the old tranformer the new one, with 10/1 ratio)
3nd try: Installed one the board, fried (not when connecting with the old tranformer the new one, with 1/1 ratio)
I measured 18kohm onto the old transformer, and the capacitor (in serial with the pulse tranformer) was reaching about 420v.
I decided that's enough. I should seek help. I am missing something.
Please note, according to the writing the fence should not go quicker than about 1Hz (he does: about 901ms period)
Here the schematics I reversed engineering except one components I can't figure what his specs are, is this a diode ?
(I got an idea but I don't want to skew people's opinion)
The "diode?" got a blue stripe right in the middle, I would like to know the value is supposed to be.
Here as join piece a QUCS schematic with the component named "whoami".
A photo with the unknown "diode?" circled in red (my cameras on my smartphone are dead, so no real nice close up photo yet, this is taken from a webcam)
Btw the simulation is not working for some reason (on QUCS) but it is basicaly a power side (left on the photo) and a pulse control side (right)
Also, I don't have osciloscope (i wish I had one....), no attenuation device, just multimeters able to go 600v and a capacitor meter.
QUESTION:
Does anyone can identify the compenent named "whoami" on the schematics (red circle on the photo) ?
I would be really thankful.