Home Made Ignition Devices

dauphinoise potato · Thu Aug 02, 2007 3:58 pm

I just made this ignition device using an old 6 volt ignition coil from my dads BSA lightning rocket that he sold. I used a homemade camera flash circuit whith 4 capacitors wired in parallel dumping in to the ignition coil. It gives a really nice fat white spark about half an inch long. I've also made a basic dual ignition system on a bit of wood (see below) whith two 1/4inch spark gaps. I probally won't use this on a cannon it was just an experiment. Post your ignition devices! :headbang:

dongfang · Thu Aug 02, 2007 4:31 pm

Hi,

How does it work; do you have the primary of the coil in series with the flash tube? Or simply a switch (poor thing) between the cap bank and the coil?

I´m getting rusty in electronics; would there be an SCR that can survive that job and not be too expensive?

Regards
Soren

dauphinoise potato · Thu Aug 02, 2007 4:38 pm

Hi I'm not using a flash tube, I'm just using a spark gap. I'm just using the camera circuit to power the ignition coil.

Pyro Ninja · Fri Aug 03, 2007 1:31 am

How long can the spark go for

I want an ignition coil...where abouts in a car are they?

Marco321 · Fri Aug 03, 2007 2:20 am

Pyro Ninja wrote:How long can the spark go for
I want an ignition coil...where abouts in a car are they?

They are attached to the spark plugs i think, they create the spark.
You can pick old ones up form auto repair places, or buy them relativly cheaply.

If you want you can make something called an induction coil, which is basically the same thing. Here are 2 links for them : How to make one and Info on another type of one. The first one is details on a whole one, and the 2nd one uses an easier to make relay.

I'm planning on making one in about 2 weeks.

Pyro Ninja · Fri Aug 03, 2007 3:23 am

Okay thanks for the info Marco

dauphinoise potato · Fri Aug 03, 2007 4:02 am

It doesn't give a continuos spark because the capicitors dump all there eleectricity in at one time. I tried to make an interrupter but this ignition coil is to weak and won't give a spark with one, but I got a continuos electric shock. Me and dad will hopefully make an ignition coil driver that gives a continuos 5cm arc using a 555timer and 3 2n3055 transitors. Here's a link: http://www.rtftechnologies.org/emtech/coil-driver.htm

Marco321 · Fri Aug 03, 2007 4:21 am

The induction coil at school gave a continuous spark, it just used a device similar to an electric doorbell that uses a mechanical interrupt. It provided a high enough and a constant enough voltage to power a Crookes tube and Geissler tube. This simulated an AC fluctuating from 0V-12V

I tried using one of the IC 555 timers to create an alternating DC current (on-off-on-off) to make a continuous spark for a transformer to step up a DC voltage. (basically an induction coil) Unfortunately it didn't work for me because i measured the voltage and the voltage went between 1 and around 9 and it needs to be either -,0,+,0,-,0,+ or 0,+,0,+. If you do get it to work i will be very great full if you can send/show/tell me how you did it.

I'm planning on using a mechanical interrupt using the magnetic field generated by the coil to cut the power, then a spring to close the circuit, this will happen in a loop.

EDIT: I just read that link with the car coil

dauphinoise potato · Fri Aug 03, 2007 4:32 am

That is pretty much what I made I used a bit of an old hack saw blade and an old coil of loads of wires I found. But the ignition coil is really weak motorbike one so it didn't produce a spark

Marco321 · Fri Aug 03, 2007 5:13 am

dauphinoise potato wrote:That is pretty much what I made I used a bit of an old hack saw blade and an old coil of loads of wires I found. But the ignition coil is really weak motorbike one so it didn't produce a spark

Oh ok.
I'm gonna use your idea of a hacksaw blade, i was trying to find something to use. Thanks