Post by thread:[EE]:Flash tube lifetime

Hi ya Jinx, ROFLMAO, sorry I had to laugh, the DSE and Altronics tube, are not suitable for 50J, I am currently doing strobe design for high speed digital photography. These units are only rated at 0.6J IIRC. I have run them at 6J, but not continuous. If you want continuous, I would recommend the linear strobe tube that DSE sell (as a spare part for 1's and 2's from the spare parts division, if you want more, you must buy 500+ from the wholesale division in Sydney) they are for around 6J IIRC. If you can find a wholesaler who supplies other types, I would love to know (I do not really want to use amglow or any of the other USA based companies, would prefer to use NZ or AU supplier) Regards, Kat. ____________________________________________________________________________ /"\ ASCII Ribbon Campaign | K.A.Q. Electronics \ / - NO HTML/RTF in e-mail | Software and Electronic Engineering X - NO Word docs in e-mail | Perth Western Australia / \ | Ph +61 419 923 731 ____________________________________________________________________________ {Original Message removed}

> Hi ya Jinx, > > ROFLMAO, sorry I had to laugh, the DSE and Altronics tube, are not > suitable for 50J, Nice to know that someone else is currently at it. But when you say not suitable for 50J, does that necessarily mean you have to use 50J ? As I understand it, the tube is more or less a short when ionised and the energy through it would depend on what was available (ie the reservoir cap). I don't really need the mother of all flashes, so a smaller cap is quite acceptable, perhaps in the 5u range like I expected. The tube in the original was not specified, so thanks for the info As for suppliers, if I hear of anything I'll give you a buzz -- http://www.piclist.com hint: To leave the PICList spam_OUTpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu

Hiya Jinx, If say a 0.6J flash is what you want, run a 5 or 6.5uf 440V polly capacitor (the ones they use for cap start on motors) this will give you a great little strobe. I have built strobes with 22uF 450VDC axial capacitor, 680R 11W current limiter, and a standard trigger with a 4N28 opto driver. Regards, Kat. ____________________________________________________________________________ /"\ ASCII Ribbon Campaign | K.A.Q. Electronics \ / - NO HTML/RTF in e-mail | Software and Electronic Engineering X - NO Word docs in e-mail | Perth Western Australia / \ | Ph +61 419 923 731 ____________________________________________________________________________ {Original Message removed}

Jinx I would suggest you go down to your local photographic shop which has an in house D&P service, and ask for a disposable camera with a flash in it, that they have developed the film from. This will give you a complete flash unit with the sort of light output you are seeking, and a cycle time that would suitable. Something to remember about these flash tubes is that if not used for some time they will go "soft" and not work properly. This is typified by seeing the trigger pulse arc along the outside of the tube from the trigger electrode, but the main flash does not occur. This problem only tends to occur in units put away in storage for some time. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> I would suggest you go down to your local photographic shop which > has an in house D&P service, and ask for a disposable camera with > a flash in it, that they have developed the film from. This will give you > a complete flash unit with the sort of light output you are seeking, and > a cycle time that would suitable. The price sounds right !! > Something to remember about these flash tubes is that if not used for > some time they will go "soft" and not work properly So they leak like valves ? -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

>> Something to remember about these flash tubes is that if not used for >> some time they will go "soft" and not work properly >So they leak like valves ? I suspect they do - I cannot recall I ever saw the reason for it, I just know it was a common complaint when my father was repairing them in Wellington (which is where I grew up). If you were in Wellington I would get him to look some disposables out for you. I believe the itty bitty ones like in disposables and the other built in ones run to about 200-250V on the tube. The older Japanese separates that slide onto the camera were pushing the tube technology using 300-350V, where most of the German stuff used 500V. I understand that the units commercial photographers used in the early 1950's used about 2000V on the tube, and with oil filled paper capacitors as the reservoir had an extremely short flash time - as in being able to get a sharp in focus image of the outer edge of a ballerinas dress while she was doing a spin. The later 500V units with electrolytic capacitors had too much esr in the capacitors to achieve this short a pulse of light. You may find that the wiring to the tube from the reservoir capacitor seems to take a long route around the camera, when you dismantle it. This is because the self inductance of the wire is used as a current limiting impedance when the tube flashes, so the capacitor and tube are both operated within safe limits. Some early flash units that could turn off the flash tube used this inductance as part of that function, it may still be done that way if the function exists on the flash. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

If they don't have the used camera, buy a new one, carefully remove the outer carton, crack open the case and you will get a 35mm roll (with a few frames ruined), a nice AA alkaline battery and the flash unit. The 35mm roll can be used in any 35mm camera. :-) > I would suggest you go down to your local photographic shop which has an in > house D&P service, and ask for a disposable camera with a flash in it, that > they have developed the film from. This will give you a complete flash unit > with the sort of light output you are seeking, and a cycle time that would > suitable. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> Wellington (which is where I grew up). If you were in Wellington I > would get him to look some disposables out for you I'll nip off down to the photo shop in New Lynn today and find out where all the disposables go to be dissected. Already have visions of a field of flash bulbs. Wouldn't that be the Christmas gift for the super-ego ? Detector across the driveway, dozens of flash bulbs going off like arriving home is a gala event !!!! Or an imaginery throng of worshippers with their Instamatics waiting as the conquering hero exits the loo after a well-executed whizz Actually, (assuming I can get my hands on them), have a few serious uses for a pile of small re-usable flash units. That was a great idea Alan (and you too Chetan). Thanks -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

----- Original Message ----- From: Jinx <joecolquittKILLspamCLEAR.NET.NZ> > > Wellington (which is where I grew up). If you were in Wellington I > > would get him to look some disposables out for you > > I'll nip off down to the photo shop in New Lynn today and find out > where all the disposables go to be dissected. Already have visions > of a field of flash bulbs. Wouldn't that be the Christmas gift for the I thought that a lot of the innards get reconditioned and re-used whenever possible. That's what I remember hearing from a Kodak engineer. Jeff -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> I would suggest you go down to your local photographic shop which > has an in house D&P service, and ask for a disposable camera with > a flash in it, that they have developed the film from. This will give you > a complete flash unit with the sort of light output you are seeking, and > a cycle time that would suitable. Been there, done that, this very morning. Well worth the trip. Definitely Not the biggest flash bulbs, and they do take a while to get ready, but stagger the firings of a boxful and you've got something approaching a strobe -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> I thought that a lot of the innards get reconditioned and re-used > whenever possible. > > That's what I remember hearing from a Kodak engineer. > > Jeff True - however there are just so many of them it is very easy to get what you want for next to nothing. And with the Southern summer just around the corner there will be truckloads available over the coming weeks -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> How much did they charge for a empty camera? Nuffink. Staff suggested that a boxful could be had for a few dollars. Everything is there except the battery. Lens, viewfinder, numbered wheel, battery holder, springs etc etc could be used in other projects. Yet to pull the circuit apart, but it's very simple and could be re-worked onto a much smaller PCB if necessary -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Exercise caution in the disassembly process because sometimes the flash capacitor will still have a very nasty charge which bits badly. I had a small photo shop in a town I went to every week or so collect them for me. Finally had to stop it because I was running of places to put them. Never been charge a dime! Would not advise disassembly while driving even thought they generally pop apart easily due to capacitor charge! Ouch! :( Larry At 01:19 PM 10/25/2001 +1300, you wrote: {Quote hidden}> > How much did they charge for a empty camera? > >Nuffink. Staff suggested that a boxful could be had for a few dollars. >Everything is there except the battery. Lens, viewfinder, numbered >wheel, battery holder, springs etc etc could be used in other projects. >Yet to pull the circuit apart, but it's very simple and could be re-worked >onto a much smaller PCB if necessary > >-- >http://www.piclist.com hint: PICList Posts must start with ONE topic: >[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads - Imagine it / Achieve it - Dream it / Become it - Larry P. Thomas wa0gwa voice : 1 913 888-0282 Krell Technologies fax : 8960 Bond pager : 1 913 617-HELP Overland Park, KS http://www.krell.com 66214-1722 USA .....lpthomasKILLspam.....krell.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> Exercise caution in the disassembly process because sometimes the > flash capacitor will still have a very nasty charge which bites badly. Yes, that crossed my mind yesterday. The cap is a 330V 120u which as you say will make you think twice about where you poke pudgy pinkies > small photo shop in a town I went to every week or so collect them for > me. Finally had to stop it because I was running of places to put > them. Never been charge a dime! Apparently someone around here is re-filming (aaagh another noun verbalised) them. Maybe for sale at flea markets, dunno. Not a bad bit of weekend pocket money, make a few bucks on each one -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Jinx wrote on 25/10/01 21:43: > Exercise caution in the disassembly process because sometimes the flash capacitor will still have a very nasty charge which bites badly. >Yes, that crossed my mind yesterday. The cap is a 330V 120u which as you say will make you think twice about where you poke pudgy pinkies In my experience the trigger voltage causes muscles to contract but is not particularly painful. The voltage across the tube when fully charged doesn't cause contraction but is significantly more painful- like having a needle put down the end of your finger..... Don't ask..... Ben -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

>In my experience the trigger voltage causes muscles to contract but is not particularly painful. The >voltage across the tube when fully charged doesn't cause contraction but is significantly more >painful- like having a needle put down the end of your finger..... >Don't ask..... Now imagine the effect when touching a 500uF 500V capacitor bank when fully charged .... again don't ask Or being out on a callout to fix the flash tube in a microfiche duplicator around midnight, and carefully turning the machine off, to do things around the tube, touching both ends to find that there is still about 3kV DC between the ends of the tube because turning off the power did not turn off the DC supply..... This one was a real danger as I had shorted each end of the tube to chassis in turn to make sure there was no energy left, only to find that the whole supply was isolated from chassis by several megohms, so my shorting trick did not work. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> the tube to chassis in turn to make sure there was no energy left, > only to find that the whole supply was isolated from chassis by > several megohms, so my shorting trick did not work Well, the second one did ;-))) -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

>> the tube to chassis in turn to make sure there was no energy left, >> only to find that the whole supply was isolated from chassis by >> several megohms, so my shorting trick did not work >Well, the second one did ;-))) Umm, yes, it was also between two hands - and the operator who was pregnant was standing on a stool behind me! Luckily my reaction wasn't too violent, just dropped everything in a hurry. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> >Well, the second one did ;-))) > > Umm, yes, it was also between two hands - Oooh, nasty - potential Code Blue I was surprised to learn that a defribrilator doesn't actually get the heart started. It neutralises any irregularities like spasms by over- powering them, leaving the then stopped heart to find its natural rhythm It still gives me the willies to see people like Dr Megavolt take that lightning through his suit, or those mad buggers who play around with Tesla coils > and the operator who was pregnant was standing on a stool behind > me! Luckily my reaction wasn't too violent, just dropped everything in > a hurry And I'm ready with "lucky she didn't too" -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> It still gives me the willies to see people like Dr Megavolt take that > lightning through his suit, or those mad buggers who play around with > Tesla coils Err, I thought that the point of Tesla Coils and the like was that they generate AC current of a frequency high enough to not affect the human nervous system. Hence all the neat stage tricks involving great long sparks and Fluro tubes, etc... That is, you can't get a "shock" from RF. (enough watts will still burn you of course) ....................... Zim -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> Err, I thought that the point of Tesla Coils and the like was that they > generate AC current of a frequency high enough to not affect the > human nervous system. > > Hence all the neat stage tricks involving great long sparks and Fluro > tubes, etc... > > That is, you can't get a "shock" from RF. > (enough watts will still burn you of course) > > ....................... Zim That may be so, but take a look at just the front page of http://www.drmegavolt.com/ Apart from the electricity aspect, what about magnetic effects ? There is some concern about VHT power grid lines, cell phones next to brains and even household wiring "allegedly" causing problems in body cells. I wonder whether in a few years Dr Megavolt will be riddled with cancers -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Well Dr. Megavolt is just imitating Tesla, and he made it to the age of 86. {Quote hidden}> -----Original Message----- > From: Jinx [EraseMEjoecolquittspam_OUTTakeThisOuTCLEAR.NET.NZ] > Sent: Monday, October 29, 2001 1:16 PM > To: PICLISTspam_OUTMITVMA.MIT.EDU > Subject: Re: [EE]:Flash tube lifetime > > > > Err, I thought that the point of Tesla Coils and the like > was that they > > generate AC current of a frequency high enough to not affect the > > human nervous system. > > > > Hence all the neat stage tricks involving great long sparks > and Fluro > > tubes, etc... > > > > That is, you can't get a "shock" from RF. > > (enough watts will still burn you of course) > > > > ....................... Zim > > That may be so, but take a look at just the front page of > > http://www.drmegavolt.com/ > > Apart from the electricity aspect, what about magnetic effects ? > There is some concern about VHT power grid lines, cell phones > next to brains and even household wiring "allegedly" causing > problems in body cells. I wonder whether in a few years Dr Megavolt > will be riddled with cancers > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> Now imagine the effect when touching a 500uF 500V capacitor bank when > fully charged .... again don't ask Oh but that's only 62 Joules. Try 30kV 2uF (900J). There is no need to touch it, it's enough if it is shorted at less than 1 meter of your ears & eyes. 900J is about half the energy of a M16 round at the muzzle (about 1800J). Peter -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> That is, you can't get a "shock" from RF. > (enough watts will still burn you of course) 'Enough Watts' in this case starts at about 25W. Most serious Tesla coils (the kind you see pictures of on the web) run at least ten times as much power. Peter -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

From: Jinx <@spam@joecolquittKILLspamCLEAR.NET.NZ> > I was surprised to learn that a defribrilator doesn't actually get the > heart started. It neutralises any irregularities like spasms by over- > powering them, leaving the then stopped heart to find its natural rhythm > Absolutely, if you heart has stoppped (ie flat line) then defib'ing is not good what so ever. You may as well whistle. Well actually, in real life you do CPR whilst you whistle, using the defib is only going to warm up their chest wall and smoke a few chest hairs. However, if the patient is in ventricular fibrillation (spontaneous contractions starting from all over the lower part of the heart at rapid speed) or ventricular tachycardia (rapid activity with origin in the ventricles) then a good slap with the defib often sorts things out. Of course sometimes it just sends them into asystole (flat line)..... Big doh..... Get whisling again and more CPR.... It's the day job again...... Ben -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> Absolutely, if you heart has stoppped (ie flat line) then defib'ing > is not good what so ever. You may as well whistle. Well actually, > in real life you Guess I'll get Baron Frankenstein off that pedestal then ;-((( -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.