Dont try this one at home kiddies....

shrtcirkt

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Well, I have been working with some slave flash circuits to use on the digitals and I decided to try and extend battery life by switching to a sealed battery.
The flash I was working with (I'll call him Frankenstein) is a fairly simple unit that runs off of 2 AA batteries (3vdc), and I decided to try one of Arches inventions. The AA battery falsies to run an external battery pack on the OWls seemed to be the perfect solution.
The only problem is that I decided to try a battery that I had sitting around, a 4 volt 9AH  sealed lead acid battery. Hmmmm, if 3 volts is good, 4 must be better......
so after wiring everything up I powered the flash up and the charge light came on almost instanty, so I said to myself, Self, man that charged up fast, now lets push Frankies test button and see what happens.
Well, the flash went off and poped like a bolt of lightning, even seemed brighter. I could hear the cap sing for an instant and the charge light came on almost before the bright spots were gone from my eyes.
I hit the test button a few more times and every time Frankie lit up the shop and began singing the charge the cap song and the ready light came on almost instantly.
I said, Frankie... we're in business.
About that time Frankie said NO WAY, and began spitting out smoke from all kinds of nooks and crannies in his plastic case.
Now we all know that electrical items run on the smoke that is preinstalled in them at the factory, and once that smoke gets out it's all over.
I left Frankie covered on the bench, awaiting a disection and post trauma autopsy at a later date.
I've got "bride of Frankenstein" standing by but I think I will go ahead and find a 3 volt regulator first.....
.... to be continued.....
 



Passthru

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:laffin-yellow: @shrtcirkt,just when you think you got it,the smoke escapes into thin air.
 

MBullism

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LMAO!  I'm electronically challenged, hehe.  The one electricity class in college wasn't near enough for me to understand the things you guys talk about sometimes..  but you'd think in a whole semester they'd've at least mentioned the factory installed smoke! (LOL)  It's all so clear to me now...!

Excuse my ignorance, but there's NO way you could use BBQ smoke, or even cig smoke to help ol' frankie out?  
 

Archilochus

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Ahhhh... sounds all TOO familiar!!  :-0

One possibility....  It could be that the higher voltage wasn't the cause of the lost magic smoke.  From what my weakening brane remembers, a typical flash charging circuit in a cam is current-limited much by the properties of the small batteries used (AAs).  That big ol' lead-acid job can supply a VERY large instantaneous current to the flash charging circuit - that could be what toasted it.
Maybe ask about the subject on the sci.electronics.design or one of the photography newsgroups??

Arch

Good to hear the batt adapter worked out..... :))

(Edited by Archilochus at 4:47 am on June 1, 2002)
 

shrtcirkt

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MBullism, My first electronics class while in the military covered all of the basics of electricity and electronics. The one thing that was mentioned early on by my lab instructor when asked "Why did it do that, or  why didnt it do that) He would always reply, "that's cuz it is "FM"" But when asked what FM was, he always said we would learn it later in the course. It was close to the end of the course that we finally learned that "FM" meant F- - - ing Magic". This was the same instructor that used to charge up small dc caps and place them in the urinal for some unsuspecting newbie to P on.... you can imagine what that did.. LMAO... 30 years later and I can still hear screams echoing in the halls.
Oh, we didnt get into the smoke until much later, for some reason that has been a closely guarded secret... I think it is derived from some sort of ummm... plant.....

Arch, I think that you are on to something there, the cap charging can probably draw in more current then the rest of the circuit is capable of handling. You wouldnt happen to have a nice compact current limiting circuit in your bag of tricks somewhere.. would you?

I am leaving for CA, tomorrow for my Sons graduation, so I wont be able to follow up on old Frankenstein until I get back in 2 weeks.
 

gantley

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well guys.... everyone needs to learn about caps and smoke first hand.

i was the dumb ()*& that shorted out a charded 6800 mf cap with a pocket screw driver.  needless to say, i respect caps in a much much great degree now.....

de ki5lr... and i should have known better too.....
 

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