Flashlamp Video

[planters]

How heavy are your capacitors? The uneven surface of the dolly will probably require you to put a piece of plastic between it and the capacitors. You might consider what you will do with these capacitors and build an enclosure that can support or house the other components such as rectifiers, transformers pressure gauges etc.

[Draco]

from my measurements the bottom flange on each capacitor will be on the carpeted section so almost over the wheels, i can then bolt the caps to the dolly. a cart will come about in the future, i have a cart in the back yard that i plan on using but it's just an aluminum skeleton, they originally supported the full weight of a heart bypass machine during assembly but that has since been discontinued so they have very nice wheels i just need to make the shelves
but right now the power supply will be on a table and the caps under the table with that set up i can glue or use 3m VHB tape to hold the plexi to the caps until i can make something better.

just a running thought for now

[Draco]

I dug out another cart but the caps would need to be on the top and i would lose my tool cart

[planters]

I made another small change (I hope for the better) in my flash lamps yesterday. After hundreds of high energy discharges there is a build up of deposits very close to the electrodes and most of it, outboard from where the discharge should have terminated. There is some degradation of the silicone "O" rings and I suspect they are the source. So, I took a short length of indium wire, .5mm thick and placed one wrap and twisted it off right on top of the new "O" rings. This is too thick to fall into the gap between the electrode and the glass, but so thin that it is nearly as flexible as the silicone. Hopefully this will protect the organic from the discharge energy that sneaks around the electrode.

[Draco]

i think i forgot to ask this long ago but what are you using to trigger the HV pulse to fire the lamp? "other then smurfs being thrown in to circuit

I dont have a dedicated system yet to do this on an output pulse from the master clock

[planters]

what are you using to trigger the HV pulse to fire the lamp?

Happy thoughts and fairy dust. The details of the fairy dust are kinda...

Actually, you have a lot of choices. I use an automotive trigger transformer for the step up and line voltage (230) with a basic doubler circuit to charge some large snubber capacitors (10-100uF) to approx 630V. You can use a cheap timer circuit (eBay) or a mechanical, momentary switch to then switch a mechanical relay or thyrister to in turn dump the snubbers to the coil. Place the ground of the coil in contact with the ground of the discharge capacitor and the high voltage lead around the discharge tube

[Draco]

very cool, i have a few spare spark coils from cars (one even from a model t, and an actual REO Speed wagon from the 1920's . )
I did obtain 2 different interval timers from ebay, i had to teach my self how to program it due to the lac of into, I was going to use a higher power transistor to trigger the coil but never built it
it would have been for a gas operated tennis ball cannon that worked beyond my expectations but i cant find it's original ignition coil.
The only concern i had with thyristor is they conduct untill the cap is discharged, but my thinking is i have two timers, i can sync one to the other so i can interupt the cap's charging supply while triggering a flash, my concern is that the charging supply may hold the thyristor in an on state but a smaller charger should still go below the threshold of the thyristor.
oddly and off subject i was going to make an electronic Que for fireworks, the it would have charged caps to about 200 volts and then dump that via a thyristor into the iginther of the firework, i wanted to hit the thing hard for reliability

[Draco]

I did not think the spark coil would survive a hit from that much voltage, i did find mine today, the type with out any internal electronics, I am thinking that the way you are hitting a 12 volt device with that much input voltage that the output must be close to or exceed 100kv

[planters]

Typical coil step up ratios are 100:1. The MSD coil I am using has a step up of 70:1. So, with some inefficiency, I expect 40KV. In an electronic ignition, the coil is hit with several hundred volts.

[Draco]

ok, i dont have anything that new, the coils i have where fired from 12 volts and can get a generous amount of "spark" if you will, The vehicles they came from did not have a CDI or any other means of driving it with a greater voltage, just points that switched 12 volts with a snubber cap.

drivers i have built in the past ran from a 555 timer and used a power transistor as the switch, the updated one i want to build has a FET instead.

I honestly have not come across a coil pack or ignition coil driven by such a high voltage, the ones on my car have a 12 volt VCC and a trigger signal, I can scan in the service manual for my car to show that's it's low voltage. i have yet had the honor of working on a coil over plug types yet or any of MSD's stuff I guess i need to spend more time at the track and not on stock systems.

what model coil if you don't mind me asking?