Ignition Coil Driver

[Suraj143]

Guys I need to make an electronics shock circuit for elephants.Going to apply this to a metal fence.

I'm going to use a NE555 driving a power transistor to drive the ignition coil @ 4-5Hz pulse rate.

My problem is in my ignition coil it has only 3 contacts.Positive,Negative & High voltage output.

Is it ok if I just connect the H/V output to the metal fence & positive & negative terminals to the circuit side?

 

[Reloadron]

Most circuits use a 2N3055 power transistor to drive an ignition coil. A Google of "Ignition Coil Circuits" will bring up a collection of circuits like this one. Three terminals is normal as you have a common ground connection on the coil. If the fence is metal and grounded the no, you can just connect the HV output to the metal. Electrified fences normally have stand off insulators with the high voltage wire isolated from ground. You can't electrify a metal fence that is grounded.

Ron

 

[DerStrom8]

Usually you would have the entire circuit grounded to a metal stake pounded into the earth. The high voltage output is normally a high voltage with respect to the ground of the circuit, so the HV output on a wire fence should work to keep animals (who are touching the ground) away from it. As Ron mentioned, though, it really depends on the type of fence. If you just have some posts in the ground and wire strung between them (with standoffs), you should be fine. If you have a chain link fence, however, that is built into the ground, it will not work. It will simply create a dead short.

 

[Suraj143]

Ok guys thanks for the info. I'll do as you suggested.

Here is the circuit I’m going to build.Please correct it.
Specially I need to protect the 2N3055 from self induction by the induction coil.

What are the values that used in the Snubber?

Is there any modifications?

 

[Suraj143]

Hello guys I need your help.

I've seen in many ignition coil driving circuits they used the free wheeling diode across GND & collector of the transistor.Not across the ignition coil.

Whats the reason to this?

Also for snubber they don't use a resistor, just placing a capacitor across the transistor???Those stuff are never to me.

 

[Suraj143]

Can somebody assist me

 

[crutschow]

Ok guys thanks for the info. I'll do as you suggested.

Here is the circuit I’m going to build.Please correct it.
Specially I need to protect the 2N3055 from self induction by the induction coil.

What are the values that used in the Snubber?

Is there any modifications?

The circuit looks ok as is.

Didn't the site where you got the circuit also have the component values?

 

[Suraj143]

Hi Carl thanks for confirming.

I designed this circuit I don't know what are the values that I can use for this snubber?

I still doubt in some circuits they place that freewheel diode across the output transistor not across the inductor coil.

In snubber also they don't use a resistor only put a capacitor.But that also across the transistor?