Spudwiki problem

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DYI
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Sat Apr 12, 2008 4:39 pm

Ever since I've been on the forum, there's been a tutorial on how to rig up an ignition coil with a camera flash circuit for a high voltage spark. Quite simple in principle. I'd never doubted the accuracy of the tutorial, because it's been around forever, and nobody's changed it, other than to add a comment about sparkplug wire's high resistance.

So I was rather suprised when the circuit I'd build, following the tutorial exactly, failed to work. The really disappointing thing: It didn't even charge the capacitor. Hopefully someone can take a closer look at the tut., find the problem, and fix it.

Here's a picture of the circuit I built:

Image

I never made it pretty, because it does absolutely nothing.

Image

The little copper thing in the middle of the board is the charging switch.
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Velocity
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Sat Apr 12, 2008 6:03 pm

I did the same tutorial, but mine did not work either. I talked to the person who did the SpudWiki article, and he helped me troubleshoot it. I will send you his email address in a PM. Just say you saw his SpudWiki article, and would like some help troubleshooting your problem. He is very helpful.
TurboSuper
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Sat Apr 12, 2008 6:49 pm

Does the capacitor charge up when the flash board is disconnected from the relay? It should work independant of the coil.

Try connecting the coil directly to the 12V battery, bring the spark gap within arcing distance, and then disconnect the battery. That should give a small spark.
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DYI
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Sat Apr 12, 2008 7:08 pm

Try connecting the coil directly to the 12V battery, bring the spark gap within arcing distance, and then disconnect the battery. That should give a small spark.
I know that will give a small spark. I'm not looking for a small spark.

And the capacitor never charges - that's the problem.
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TurboSuper
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Sat Apr 12, 2008 7:14 pm

Well then either the photoflash board is toast, or the capacitor is toast (or you didn't wire it right). Test with a multimeter to find out which one it is. My money is on the board.

Btw, I was asking you to connect it drectly to the battery just for the purposes of testing the coil. But it seems like that's not the problem.
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jrrdw
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Sat Apr 12, 2008 8:00 pm

Your possitive all your batteries and connections are good? Would the fact that this coil was designed to be used with a larger amped battery have anything to do with only getting a little spark?

Does the circuit need to be grounded?
TurboSuper
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Sat Apr 12, 2008 8:14 pm

I'd assume a guy like DYI made sure his battery was the right way around before asking for help, still, it's a good point.

And no, the reason for having a capacitor is to compensate for the circuit's inability to source large amounts of current. The only difference battery size makes is in the charging time.
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jrrdw
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Sat Apr 12, 2008 8:29 pm

Get out the jumper cables and raise the car hood, would be a fun test!
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dewey-1
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Sat Apr 12, 2008 9:10 pm

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Last edited by dewey-1 on Sun Apr 20, 2008 11:27 am, edited 2 times in total.
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DYI
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Sat Apr 12, 2008 9:56 pm

I can worry about the relay after I get around the problem that the capacitor won't charge. Even when I bypass the relay, I get no current, and when I short the gaps of the capacitor, nothing happens, indicating that it isn't charged.
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dewey-1
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Sat Apr 12, 2008 10:14 pm

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Last edited by dewey-1 on Sun Apr 20, 2008 11:27 am, edited 1 time in total.
miskaman
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Sat Apr 12, 2008 11:11 pm

DYI wrote:I can worry about the relay after I get around the problem that the capacitor won't charge. Even when I bypass the relay, I get no current, and when I short the gaps of the capacitor, nothing happens, indicating that it isn't charged.
If that didn't work, you have a faulty board probably. That's the only thing I can think of. Did this camera flash thing work before you opened it up?
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Larda
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Sat Apr 12, 2008 11:37 pm

Just did a quick 5min test with this ignittion and it works for me.
I didn't use a relay, instead i used pushbutton.
If you are going to try this i recommend you to use a better switch because this one isnt realy safe. :)
Attachments
ignition.jpg
ignition2.jpg
ignition3.jpg
ignition.zip
A short clip when i testing the ignition.
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Push to test... Release to detonate.
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Sun Apr 13, 2008 4:22 am

You didn't contact more then the 2 necessary when bridging the charge button on the board did you?
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Sun Apr 13, 2008 5:32 pm

Sounds like your flash board is fried.

1. Disconnect everything from the flash board except the 1.5V battery.

2. "turn on" the board.
Does it whine and charge the cap?
Yes: The board is OK
No: The board is fried.

3. Can you trigger the flash (if the flash tube and HV coil are still installed)?

You didn't ever expose the flash board to the 12V battery did you? That'll fry the board pretty quick. Even a 6V battery will probably fry the board. Usually, they'll work at 3V but anything above that tends to kill'm. The input voltage to the board really doesn't matter much so there is no reason to boost the voltage above 1.5V.

Dewey-1: I added your relay image and pin descritpions to the spudwiki pages;
http://www.spudfiles.com/spud_wiki/inde ... _the_Relay
http://www.spudfiles.com/spud_wiki/inde ... tive_relay
Image
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