using car ignition coil as electric fence charger : LUSENET : Countryside : One Thread

Please provide me with simple wiring diagram using car ignition coil as electric fence charger. Kindly inform component values such as capacitors or resistants. Thanks

-- Wajih Daour (, December 19, 2001


A coil puts forth a constant shock. If you are using a battery type fencer, (12V or 6V voltswagon) you will need to get a corrosponding voltage battery and coil. To make the shock intermittant so the battery doesn;t wear down fast, use a turn signal relay (heavy duty). Ok, wiring would go as follows: positive side of battery to positive on coil. Positive on coil to (either post) on turn signal relay. Turn signal relay (and keep it DRY!) to fence. Fence needs a ground- which is a rod set in the ground. Connect rod to negative on battery, then negative on battery to negative on coil. You wont need very heavy wire- 14 gauge should be fine. For a negative back fence... which makes the fence more powerful and works much better in rocky and very dry soils, omit the ground spike and instead connect the negative of battery to a negative fence wire. Do not connect the positive and negative fence wires anywhere in system. The negative fence wire does need to be insulated in this case, and the animal you are fencing will need to contact both the negative AND positive fence wires in order to get a shock, thus making a system with upwards of 4 wires better- two grounds, two hots+. One mention. I would HIGHLY recommend, if you are fencing under 5 acres, the use of a Yellow Jacket 4 Volt solar powered fencer. The cost is 100 bucks, and wirth every penny, for my application. By the time you build you own set up, you will be pushing the 100 dollar figure. If you do go that route: make sure your connections are good. Make sure, on day one of new animal in fence, that you have had rain recently, a dewy night or wet down the areas around the fence with a garden hose. This, using the ground spike system, helps give the fencer a boost- the negative works better and the animal respects the fence quickly. If you are fencing goats... well, good luck. Your gonna need UPWARDS of 7 wires, cause they are idiots (mine are anyways).

-- Kevin in NC (, December 19, 2001.

Kevin, I don't understand your connections, is there nothing connected to the EHT terminal on the coil? What about a capacitor across the points of the turn signal unit?

-- john hill (, December 19, 2001.

Keven, a car ignition doesnt deliver any shock. It simply converts 12volts to a higher voltage. The shock from a fencer is caused by the pulsating nature of the wire. The coil is also very inefficient

-- Gary (, December 21, 2001.

Wajih Daour, did you send me an email today? If so please send it again as there was no text and no explanation of the attached PIF file.

-- john hill (, December 22, 2001.

It seems there is some confusion concerning the ignition coil in this use. DC current, the type straight from your battery, will not convert into a high volt current by passing straight through the ignition coil - only a pulse of current will do which is similar to AC, which is why there needs to be something (the turn signal control here) to keep breaking the current to the ignition coil and turning back on. The resulting "pulse" of DC current will induce a high voltage current in the ignition coil, which is what you desire for your fence - a pulse of high voltage electricity.

-- Roy A. Decker (, April 28, 2002.

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