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does anyone know how i can make an electric fence run constant and not on a pulse? Answered

what i have is a zareba model a5 ac solid state electric fence charger. when i connect the fence terminal to the ground i get some little blue sparks but only for a second at a time. and i was wondering if anyone has any ideas on how to make it run constant, or if anyone has any good ideas on what to do with it. heres a link to the specs  http://www.zarebasystems.com/store/electric-fence-chargers/a5.   thank you guys in advance for any help you can provide.


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5 years ago

All you have to do is take out the circuit board and hook the two transformers up in series with the capacitor in series between them, it will put out constant power but if it was used for a electric fence it couldn't have anything touching the fence because if it was grounded any at all it would drain the capacitor and it wouldn't be able to recharge. Doing thing changed the charger from low impedance to high impedance.

Oh and the center tap on the first transformer will no longer be used

even though you already seem to have an idea what to do and I am far from understanding most of the talk in here, is it possible that the pulsing is created by a capacitor charging up and then discharging?

Just wondering, does that IC with 8 pins happen to have the number "555" printed on it? If so, are pins 1 and 2 connected to that big electrolytic capacitor (the one labeled C2) that looks like its right next to pins 1 and 2 on that IC?

no 555 on it, i thought that's what it was but i'm not sure. and to comment on your other post(cant reply to that one for some reason.) the grey thing is indeed the transformer. the transistor is located on the board directly beside it. and by continuous i mean i would like it to arc kinda like my Jacobs ladder would. i had another one of these that i put in a different circuit and ended up frying it. i know those chips are probally whats timing it so maybe ill just pull those out and bypass them.

You should look at this thing more closely.  See if you can figure out which wire goes where, and which one of those ICs is doing the timing. 

What I'm expecting to find here is a transformer (guessing it's that big grey thing) , with a secondary winding that has many-many turns, and primary winding that has not-many turns.  Also expecting that current is switched through the primary winding by some big transistor, or maybe an SCR, a big silicon component of some kind.  I wonder if this big transistor is hiding on the back of that board, because that one little thing in the TO-92 package looks smaller than what I'm expecting.

Anyway, I'm expecting the way this thing works is that there's a big transistor that switches a pulse of current into the primary, every second or so, whatever the frequency at which you said the sparks appear. 

You use the word continuous, and I'm going to interpret that to mean you want the coil to fire more frequently than just once a second.  Like maybe 10 times per second, or a hundred times per second.  Something like that. 

If you can figure out what is creating this signal that tells this transistor to pulse on, every second or so, or if you could figure out which transistor it is that controls the current in the primary winding, then maybe you could drive it differently, and by that I mean make the sparks timed much closer together. You know: spark-spark-spark-spark-spark-spark-spark-spark-spark-spark-spark-spark...

Or maybe you could just pull out that big grey transformer, and drop it into an entirely different circuit.  I think that transformer is going to look/function similar to an automotive ignition coil, or like those ignition coils they make for lighting gas stoves and furnaces, and it could probably be used with circuits designed for generating high voltage from coils like those.

well i guess that makes seance,guess ill just stick to my flyback zapper for now. but either way making high voltage sparks are always fun either way..just kinda want to make some with this that doesn't only last a second.


6 years ago

I don't think a fence charger would have enough power to be an effective bug zapper. Its designed to give a high voltage pulse that feels uncomfortable but does not do any damage. The high voltage is for getting through things like fur and hair but not burning anything or setting it on fire. The last thing you want is a fence setting your sheep's wool on fire. Bug zappers on the other hand can burn and set bug remains on fire. So I don't think it will work for what you have in mind. My fence had a hard time killing grasshoppers. (Use a pair of long nose pliers and insulating gloves and use the grasshopper to short out the fence. Stupid thing just jumps away when you let it go, although it probably felt it had a rather bad day.)

well i have no livestock or anything else i need to keep behind a fence, my friend sold his horses and gave me the a couple chargers. id like to maybe make a bug zapper or or something. i enjoy hv projects in general and id have to say that modifying this to run constantly is far safer than say, my flyback.

Its specifically designed to NOT be continuous for safety reasons. Why do you need to defeat it ?