Danger of using old strobes?

[argos33]

I've always heard that old strobes can be very dangerous but cannot remember exactly why. Is it just because they do not have as many safety features preventing accidental shock? Or because cords can get old and expose wires, etc? Anyone want to shed some light on the issue?

I am thinking about playing around with an old 800W speedotron and well....don't want to die.

Thanks for any input/advice

Evan

[Peter De Smidt]

Well, any of the electrical or mechanical parts can go. Seeing one start arcing can be quite the sight. Black line packs are very rugged, although I don't know if that's what you have. I've used some that are older than me, and I'm not that young ;) Look for areas of damage, especially around the sync plug and the plugs for the heads. If there is some, get it fixed. Be careful when you turn it on. :)

Never unplug/or plug in heads with the power on with Speedo equipment.

[Richard Wheat]

I use three old flash units fairly regularly for extra fill. As far as I know, old strobes can be dangerous for three reasons.

A) the general electrical condition of the unit - eg. frayed power cords, earthing, damage to the unit which may have compromised its electrical saftely, etc.

B) the trigger voltage present

C) the condition of the flash tube

The first can be mitigated by submitting the unit to an electrical safety test and inspection. In Australia you could have the unit certified electrically safe against an Australian standard.

The second is only a problem if you are using modern electronic equipment to trigger the flash - eg. a digital SLR - and in this case you can obtain some sort of slave circuit to go inbetween which can handle the high voltages present. Just don't connect an old strobe directly to a modern camera. I have made a couple of circuits to go inbetween modern cameras and old strobes - they are quite simple - but you need to get them right.
If you are triggering directly from a large format mechanical shutter - no problem. As these are a mechanical switch, there is no danger from a higher trigger voltage.

The third I have no experience with but I believe that older flash tubes are liable to explode.

I also understand that an older flash tube may give you a different temperature of light - ie. one that you may find it hard to balance with a 2nd unit. I have never had this problem though. I use two modern Bowen heads with three old Courtney units and have not had any problem.

Hope this helps,
Richard.

[Jason Greenberg Motamedi]

The capacitors of any flash unit can carry enough power to kill, even when unplugged. Never open a power supply unless you know what you are doing. From what I understand, the newer ones automatically discharge the capacitors once turned off.

[Kirk Gittings]

Not sure what you mean exactly by old. I use
old strobes weekly. 30 year old ones to be exact. Many of them I am the original owner. Old Normans actually. Like my old bones, they work fine with a little TLC. Hear a weird noise? Smell something funny? Run it in to the repair place.

[ic-racer]

Not sure about old strobes in particular, but the thing to remember with any strobe is that unlike a regular light bulb, the voltage is already applied to the leads of the bulb before you turn it on.

[Frank Petronio]

I've regularly used unmaintained cheap beater ca. 1979 Dynalites without problems.

What happens with a lot of older strobes is the connectors will get compromised or some fool will unplug a live cable from a pack and you'll get arcing and explosive discharges that will send the cable through drywall on the other side of the studio (or through you...) Speedotrons, Ascors, Normans are all noted for this.

I think the European and Asian packs are safer in this regard but it's a good habit to turn them off before swapping cables no matter what.

[Struan Gray]

I have an old Courtenay unit that I regard with deep suspicion, but which has yet to give any trouble. Golden rules seem to be to turn it off before plugging or unplugging anything, and to let it discharge for a long time connected to ground before doing any McGyver stuff with the case open.

In fact, unless you have a background in electronics, and high-voltages at that, I would say don't ever take the top off. The capacitors are lethal for some time after turning off, and they're more lethal than other commonly available HV sources like vacuum-tube TV screens. Proper repair shops have a shunt to discharge them safely, but it's not something you want to jury-rig.

If you do have electronics experience it's worth having a look inside because the capacitors are the elements that are most likely to have gone wrong in long-term storage. Check them over carefully for any signs of leakage or corrosion.

That said, the only bad point on mine was the lead that connected the pack to the head. The insulation was completely shot - dry, hard, cracking - and it obviously had to be changed. The plugs were also brittle, but they were commonly-available valve-base plugs so were easy to find replacements. If you have, or can get hold of, a HV insulation tester, it would be well worth checking your cables.

[Sascha Welter]

Broncolor units have a flap over the cable connectors. When you lift the flap to swap a cable, the unit is turned off. Of course... lift it just a little bit and wiggle the cable and you will be able to disconnect the cable with the unit still on. Wiggle space probably gets worse as they get older.

[rdenney]

I've never opened my Speedotron 1600. But the general theory behind fixed-ouput strobes is that they charge a very large electrolytic capacitor, and the discharge it into a xenon tube at very high voltage.

The danger is in the electrolytic capacitors. A capacitor is a storage device for electrical charge, and it can store that charge for quite a while. The charge that can be stored by the large capacitor in a flash unit (or in power supplies for devices that use vacuum tubes that require a very high biasing voltage) can kill you. Do not work on one unless you know what you are doing, such as how to discharge a large cap with a grounded high-voltage probe. They may be equipped with bleeder resistors, and the cases may have a shorting bar for safety. If you don't know what those are, step away from that screwdriver.

The electrolytic capacitors can also die of old age. They work by coating aluminum foil with a layer of oxide that acts as a dielectric, and then rolling it up so that the dielectric is between layers of the foil. They require a basic voltage to be applied to maintain the oxide layer. When they are left unpowered for very long periods, that dielectric layer can sometimes degrade, which allows the layers of the foil to touch, shorting out the capacitor. This results in a loud bang, followed by the release of smoke. The smoke cannot be reinserted, unfortunately. But you'll know if this is a problem--just set the power unit (no heads plugged in) in the middle of your garage, walk away from it, and then plug it in. If the cap is shorted, you'll hear and see the problem. Send it to Mr. Speedotron to have the smoke replaced.

If you don't get fireworks, then just let it sit, powered up, for a couple of days, and it should be good to go. If you haven't bought the unit yet, ask for a demonstration. If it works in the demo, then you should be good to go, at least as regards the electrolytic capacitors.

Very old capacitors used waxed paper as the dielectric, and those dry out and short. But I am sure that predates any electronic flash system.

The trigger voltage on these is about 300 volts. Speedotron makes a low-voltage switch interface that you should buy before using this with any electronic camera, though it should be fine with mechanical view-camera shutters. That device is only about a 1" cube and plugs into the dual-spade receptacle for the sync cable. Note on that receptacle: It looks like a regular 120VAC plug. BUT IT ISN'T. Confusing the two can have disastrous consequences. I bought one of those interfaces from B&H a few years ago and have used my 1600 Brown Line head with digital cameras with no issue. Install that device and leave it--it will work fine with all shutters.

I would not worry about the flash tubes. I suppose they can get old and gassy, but I've never seen it and mine are still perfect even after periods of both intense use and inactivity. Also, the tube itself is enclosed in a glass enveloped that will at least eliminate any reference to the word "shrapnel". Flash tubes can always burn out, though. Tubes for the MW3R and the M11 heads are still made and available from B&H, as are all the accessories for both the Brown Line and the Black Line. But if your power supply is an 800WS model, I'd be willing to bet it's a Brown Line.

Finally, check the extension cords for the heads. If they are cracked, replace them. They carry high voltage and cracks will give that voltage a place to leak out if there is something attractive (like your hand) to leak to.

Rick "whose Speedotron 1600 system has been a real workhorse" Denney

[Gene McCluney]

In actual fact, any electronic equipment that uses large electrolytic capacitors, such as studio strobes benefits from use. If you use the equipment regularly, it keeps the capacitors "formed". Lack of use over a period of time can cause the capacitors to fail.

[argos33]

Thanks everyone for the info/replies. The unit is a speedotron 1200Ws. I put it in the center of the garage and plugged it in from a distance and no bang, smoke, fireworks etc.

It looks like someone replaced the cable connection points, however the pins are bent on most and won't even plug in. What a pain. I suppose I will just bend them back and guess and check until they plug in. Would a small amount of dialectic grease on the pins be a bad idea?

Evan

[rdenney]

It looks like someone replaced the cable connection points, however the pins are bent on most and won't even plug in. What a pain. I suppose I will just bend them back and guess and check until they plug in. Would a small amount of dialectic grease on the pins be a bad idea?

Oooh. I don't like bending those pins on the mil-spec round connectors, especially if the power supply has been charged up. I'd wait a day or so to let those caps dissipate before attacking those pins. Or, if you can get one of the heads to connect, fire the power supply to make sure the charge has been dissipated. Make sure you use one of the big heads (an MW11) if you just plug in one. Then, I would bend them very gently with needle-nose pliers.

It does not bode well that the power supply has lived so hard a life that those pins are bent!

Do you have a photo showing the top of the power supply that shows some detail? Posting that might lead to more specific advice.

Rick "glad no smoke escaped" Denney

[Steven Barall]

It's what Frank says about the arcing problem with old strobes. I believe that Dynalites were the first strobes that were protected from this. Back in the day I arced out an old Thomas Strobe unit and almost killed myself. All the connecting pins in the pack and the head melted. Old timers still turn off power packs when they plug in and unplug heads.

Just as an aside, I worked for a guy who used Norman strobes and the pack, for some reason, discharged the power through the sync cord and into the camera and into him. It stopped his heart and almost killed him.

[Frank Petronio]

I've felt a tingling Copal before too!

[Jason Greenberg Motamedi]

I was reading somewhere on the web that to reform an capacitor that has not been used for a long time, one should plug in the power unit for five seconds or less, then let it sit for a 10 minutes, and repeat this process a few times. It sounds like a bit of internet pseudo-science, but I can't be sure... Any opinions?

[rdenney]

I was reading somewhere on the web that to reform an capacitor that has not been used for a long time, one should plug in the power unit for five seconds or less, then let it sit for a 10 minutes, and repeat this process a few times. It sounds like a bit of internet pseudo-science, but I can't be sure... Any opinions?

For people who live and breathe this stuff--radio amateurs who revive old vacuum-tube transmitters that have 2 or 3 kilovolt power supplies with enormous filter capacitors--they would tell you that the best way is to power up just the power supply using a Variac, increasing the voltage slowly and gradually up to full service voltage, and then leaving it that way for a couple of days. This allows the dielectric coating to rebuild at voltages too low to arc.

Doing that with a Speedotron power supply is silly, though. First, you can't separate the power supply from the rest of the circuitry, and the low voltage wouldn't be good for it. Secondly, they aren't that old. Thirdly, who has a Variac? And finally, radio amateurs are tested (sort of) and licensed to do that sort of thing, along with receiving ample warnings about the various dangers involved in messing about the innards of a kilovolt power supply.

So, just plug the thing in. If it pops and smokes, send it to Mr. Speedotron or find another used one.

Rick "no stranger to the chicken-stick and the one-hand rule" Denney

[Greg Blank]

I have a Variac :)

[QUOTE=rdenney;528949] Thirdly, who has a Variac?

[BrianShaw]

I have a Variac :)



Thirdly, who has a Variac?

me too. :o

[erie patsellis]

Broncolor units have a flap over the cable connectors. When you lift the flap to swap a cable, the unit is turned off. Of course... lift it just a little bit and wiggle the cable and you will be able to disconnect the cable with the unit still on. Wiggle space probably gets worse as they get older.

From the 404 on there is either a flap or handle. Probably the most dependable and prevalent classic Bron pack out there, the 304, doesn't have this interlock. Even with it, it's a good idea to get in the habit of turning the pack off (and firing the open flash, if possible) before plugging or unplugging a head.

[rdenney]

me too. :o

Well, then both of you guys know what to do.:cool:

Rick "yeah, yeah, yeah" Denney

[Jason Greenberg Motamedi]

Well, as it happens I also have one...

[erie patsellis]

I have a Variac :)

[QUOTE=rdenney;528949] Thirdly, who has a Variac?
Hey! I have two, though one lives in my Devere Enlarger. I have another wired with a male and female 20A plug/jack just for these kinds of projects.

[rdenney]

So, large-format photographers have the largest collection of Variacs outside of professional electronics labs, repair shops, and ham shacks. Who knew?

Rick "no good darkroom or studio is complete without one" Denney

[Diane Maher]

I think I have a Variac too.

I have some old strobe lights. Maybe if I post some pics here someone might be able to help me with them. I have no idea what to do with them, but know that one of them plugs into a board that has one of my lenses on it for my Century 7A Studio 8x10. It would be cool to get it to work, but I have no idea how to go about that.

[Jim Jones]

Early electronic flashes (Kodatron, Ascor, etc.) charged an oil filled capacitor up to a few thousand volts, and often put a few hundred volts through the shutter sync contacts. They should be used with utmost caution. Only one of my three Sylvania Wabash flash units from about 1950 is still working. The power transformers in the other two have failed. Also, insulation on the wiring is failing. At 2000 volts, this is serious. Their flash tubes are expensive when available. Newer electronic flashes can store a lot ef energy in electrolytic capacitors at maybe 300 volts. This can be as deadly as the older high voltage flashes, despite improved safety features. In normal use modern flashes should safe, but one should read the instructions and use them with care. Heed the warnings in previous posts.

[eddie]

interesting read. electricity tried to kill me when i was 9 months old....i guessi better be careful now with my flash units....it may try it again.

mine are "old" photogenic strobes. with the cats iron rollers and the "power box" i all do is plug in the release cable and occasionally up plug them from the wall to role em around. so far so good....now i am worried. they have power to them all the time and i use em a couple times per week......

e

[rdenney]

now i am worried.

No need to be. Just keep an eye on the cords and have them replaced if they start to crack. The old stuff is in a metal enclosure that will contain any startling failures. If it is of the vintage to have oil-filled cavity capacitors (which I didn't even know existed until two posts ago), then maybe it's time to upgrade.

If you leave it on and use it, those caps will last much longer than if it sits unused...

...like my Speedotron unit.

Rick "sigh." Denney

[henrysamson]

Years ago I built some strobes from scratch. I used them a few times but they were dangerous and I did not trust my homebuilt power pack. The ones I built were pretty simple and the capacitors were charged at 300 volts (or about that). This voltage is applied to the connectors at the ends of the flash tube. But nothing will happen because the xenon gas will not conduct until it is ionized and that is what the wire wrapped around the tube does. When fired very low current but very high voltage (10kv?) is applied to the trigger coil which ionizes the gas and then the charge stored in the capacitors dump through the xenon gas and make it "glow". The problem is that the 300 volts is applied across the plug pins for the heads when the pack is charged and pulling the cord on a charged packs allows the charge to arc across the pins as they exit the plug. BANG!

I bought a 1200 WS Speedotron set over 20 years ago and only had trouble once. I heard some arcing inside the power pack and smelled something burning. It was pretty obvious that something was wrong. I turned it off and fired it and sent it off for repair. No trouble since then and that was about 7 years ago. I think the capacitors were arcing internally. BTW, the speedatrons fire when you turn them off to avoid the capacitors staying charged. I would not worry about your 800ws speedatrons.

[rdenney]

BTW, the speedatrons fire when you turn them off to avoid the capacitors staying charged. I would not worry about your 800ws speedatrons.

Yes! I had forgotten that--thanks for the reminder.

Rick "wondering if that repair was expensive" Denney

[Armin Seeholzer]

I hade for about a year ago some exploded capacitors inside my Hensel 1000 Ws and a brown soup was running out from the front and ruining my embrella and it smoked quit a bit. Maybe I flashed it to fast at full power for macro work.
Is it really better to use them regularly I heard thad booth ways.
Some sayed regularly is the best an other told me ether way, the capacitors will get worse with age!
Whats true?

Cheers Armin

[rdenney]

Some sayed regularly is the best an other told me ether way, the capacitors will get worse with age!
Whats true?

It depends on the quality of the capacitors, among other things. But if it's true, then the only thing to do is use them until they die.

I'm assuming that the brown soup was dielectric oil, which would signify a very old design.

Rick "who has always seen large aluminum-film electrolytics inside strobe circuits for the last 30 years or so" Denney

[Armin Seeholzer]

The Hensel Flash was new in 1996 so not thad old by the way!


Cheers Armin

[rdenney]

The Hensel Flash was new in 1996 so not thad old by the way!

Even aluminum electrolytic capacitors have an electrolyte that is in liquid (more like a paste) form. That stuff, though, is usually either contained in the cap case when it arcs over or it goes up in smoke, and least for the small caps I've blown up.

Rick "whose experience with blown electrolytics does not include large power supply capacitors" Denney

[jp]

So, large-format photographers have the largest collection of Variacs outside of professional electronics labs, repair shops, and ham shacks. Who knew?

Rick "no good darkroom or studio is complete without one" Denney

No crackpot practitioner of science is complete without one. I've got one. If the variac has a floating output (neutral not grounded), it would be much safer to use a strobe with it, as you would be using isolated electricity.

[argos33]

Here are some pictures of the unit. You can see that some of the pins were misaligned enough that they got pushed in when the connection was screwed on. The others are bent enough that they will not plug in... I'm guessing I won't be able to just pull them back out and will have to take the piece apart to reattach/secure them.

Or maybe it's worth just buying new attachments (or taking it in someplace) assuming the parts are available? Any suggestions?

[argos33]

Picture of light and strobe type:

[brian mcweeney]

You have a 2400ws Speedo pack not an 800 ws pack. It's probably 25 years old. The strobe head looks ancient. Looks like that's where your problem is.

[argos33]

Yes, sorry I had only glanced at it when making the original post. I'd say the main problem is that I can't even plug them in to try them. Although old, they look like they are in working condition. I figure I could just use them until they went out and if I can't find replacement parts no big deal.

[Peter De Smidt]

I've used Speedotron packs much older than that. Send the light/cord in to have it checked out/fixed.

[rdenney]

Here are some pictures of the unit. You can see that some of the pins were misaligned enough that they got pushed in when the connection was screwed on. The others are bent enough that they will not plug in... I'm guessing I won't be able to just pull them back out and will have to take the piece apart to reattach/secure them.

Or maybe it's worth just buying new attachments (or taking it in someplace) assuming the parts are available? Any suggestions?

That is a Speedotron Black Line 2401, not a Brown Line 1201 like you thought. It's capable of 2400 ws total, and will run six heads instead of four that the Brown Line power units support. This one is an older one (anout the same vintage as my Brown Line D1601)--you'll definitely need the low-voltage trigger interface for modern electronic cameras.

But that isn't the problem. The problem is that you are trying to plug Photogenic heads into a Speedotron power pack. I don't know if there are any pack/head systems that are interchangeable--I've never explored it. But in this case, the fact that I count six pins in the head's plug and 7 holes in the power pack's receptacles is not a good sign vis a vis compatibility.:rolleyes: I have this feeling I can explain the bent and broken pins.

Used Speedotron 102 heads, which is what you need for this pack, seem to run in the $100 range.

Rick "hmmmm." Denney

[Peter De Smidt]

Good catch, Rick! I should've been paying more attention. 102 heads are what you want. It's a good pack. Make sure to use it on "slow" recharge with 15 amp circuits. Check out the sync connection, these are often a bit dodgy. I've seen the packs start sparking at that point. The replacement socket isn't expensive. If you put a photo eye with a household plug in the sync socket, you can fire the pack using a small flash on the camera.

[Frank Petronio]

Dang should it be commonsense that one brand of head is not going to fit another brand of pack?

There is no such thing as a stupid question but... this one is awfully close!

[argos33]

My apologies, I should have looked it over more before posting. I just didn't know anything about these and didn't want to electrocute myself. Thanks for the help regardless.

[neil poulsen]

I wouldn't mess with older strobes for anything.

Here's an experience that I had. After taking an architecture workshop with Norman McGrath, I was ready to buy some strobes and found a pair of older Norman P4000 packs at our local pro photo store. After a quick explanation, the sales person turned his back and let me experiment. I thought I was being careful: The strobes had powered up, and I was interested in trying a different power setting (watt-seconds). I turned off the pack, pressed the discharge button a few times, and changed the power setting. Ker-whapp! That P4000 lit up like a Christmas tree.

That scared the hell out of me, and that was it. I walked out the door, and they had a dead power pack on their hands. It's a good thing it wasn't the other way around.

I purchased a set of new Dyna-Lites on a student discount, and I've never had a problem.

[Peter De Smidt]

Neil's right that new packs should be more reliable and safer than older packs. That said, I had two new Dynalite packs start strobing on me, as in like a disco light. This damaged the packs. It turns out that there was a defect with the product which Dynalite knew about, but which they didn't feel was important enough to let customers know.

[erie patsellis]

Dang should it be commonsense that one brand of head is not going to fit another brand of pack?

except for Novatron (older 5 pin) and Speedo Brown line....

[Annie M.]

YIKES!! I have an old set of 4 Photogenic Studiomaster II 200 watt-sec with all the stands booms heads etc. .... I was going to fire these up this winter... they have been stored in the garage... it is damp here... I assume that now these should be taken to the dump... yes/no? If they power up fine does that mean they are OK or are they an accident waiting to happen?

[lenser]

Annie, I just acquired an even older set of Flashmasters that dated from the fifties. They were absolutely covered in dust so I thoroughly cleaned the cobwebs and dust off all three power packs prior to trying to charge them up and had an electrician install grounded power plugs to replace the old two prong type that were not grounded. Fired them up and they work like a charm.

I was concerned about possible arcing across contact points with the cobwebs, but that was it. No problems once they were completely cleaned up.

I would not charge them up before cleaning as that would recharge the capacitors and that could be serious if you grounded during the cleaning process.

[Annie M.]

OK... here is the plan I'll give them a dusting... I'll put them out on the deck for testing and use an inside plug with a wall switch while wearing my gumboots... thanks!

PS... if there happens to be an estate sale of my photographic equipment in the next while DON'T BUY THE STROBES!!

[rdenney]

YIKES!! I have an old set of 4 Photogenic Studiomaster II 200 watt-sec with all the stands booms heads etc. .... I was going to fire these up this winter... they have been stored in the garage... it is damp here... I assume that now these should be taken to the dump... yes/no? If they power up fine does that mean they are OK or are they an accident waiting to happen?

It's easy to get panicky about old high-voltage electronics for those who don't have expertise or knowledge of electrical devices, but really it's easy enough to protect yourself. One is by making sure the devices has a grounded plug (read: three prongs) and that the receptacle you plug it into also has three prongs, properly grounded. Any arcing inside the unit because of a failure will find an easy path to ground if you do that.

With any old unit that has been in storage, just vacuum the dust off of it, put it in the middle of the garage, plug it in, and turn it on. Steel your nerves before throwing the switch. If you are particularly concerned, use a wooden stick to operate that switch. If there are fireworks, pull the plug, and then take it to the dumpster (or have it repaired). If not, then just use it and don't worry about it.

This procedure is for those who are concerned. When I bought a Brown Line power pack, it was old, but I just plugged the darn thing in and started using it. It works great.

If the insulation on the cords to the heads is cracked, have them replaced.

The real danger of these units isn't outside the box, but inside it. Don't go there if you don't have the needed expertise. That applies to the old Vivitar 283 camera-top flash as much as to studio lights.

Rick "not living in fear" Denney

[W K Longcor]

Please excuse my question -- after all the good answers -- My once technically adept brain does not process some of this stuff as well as it used to. Here is my situation. I have a Speedotron Black line 2400ws unit that was purchase new somewhere around 1990 -1992. It went into storage in 1997 and has not been touched since.

So, wanting to use it again -- I'm going to put it in the garage -- or out in the driveway on a nice dry, sunny day -- and plug it in with a long, heavy duty extention cord.

1- Should I have a flash head plugged in ?
2- How long do I leave it "on"?
3- Do I "cycle" on and off at all?
4- Do I "fire" the flash tube at all during this process?
4- Am I correct in thinking that the unit may not put out full power until the capacitors are fully formed and "exercised"?

By the way - I DO have a variac -- But I'm guessing from reading here that I don't need to bother with it.

Over the years I have experienced three different stobes go POP! -- Works better than Exlax!:D

[Annie M.]

OK... I powered one up it worked fine.... but the the Photogenic online info on this product says to keep the capacitors 'formed' the unit should be powered up every 60 days... these units have been idle for 5 years. I love the groovy retro look of this equipment... but am not interested in garnering a Darwin award... is there some kind of 'electrician' that can look at them and tell if they are safe to use.

Oh... and how does one 'discharge' the unit... I just popped the flash and unplugged it. Is the unit now sinisterly waiting to blow up in the middle of the night?

[rdenney]

1- Should I have a flash head plugged in ?
2- How long do I leave it "on"?
3- Do I "cycle" on and off at all?
4- Do I "fire" the flash tube at all during this process?
4- Am I correct in thinking that the unit may not put out full power until the capacitors are fully formed and "exercised"?

Were it me, I would plug the thing in with heads attached, and fire away, not worrying about it.

After a few deep cycles, the capacitors will be back up to snuff even assuming they aren't now.

Rick "make sure your heads add up to more power than you are putting into them" Denney

[rdenney]

OK... I powered one up it worked fine.... but the the Photogenic online info on this product says to keep the capacitors 'formed' the unit should be powered up every 60 days... these units have been idle for 5 years. I love the groovy retro look of this equipment... but am not interested in garnering a Darwin award... is there some kind of 'electrician' that can look at them and tell if they are safe to use.

Oh... and how does one 'discharge' the unit... I just popped the flash and unplugged it. Is the unit now sinisterly waiting to blow up in the middle of the night?

Do not worry about discharging it. You only need to worry about that if you go poking around inside it, and I know you are not contemplating that.

And if it works, it works. Use it and don't worry about it. Several deep cycles will reform the capacitors.

Rick "who has not found capacitors to be quite that sensitive" Denney

[Jason Greenberg Motamedi]

For what it is worth, I just got off the phone with a technician at Speedotron, asking about my 2401a (so this doesn't help Annie). Echoing what others have said here, he told me that to "reform" the capacitors I should plug it in and let it sit for two hours. He said it would be preferable to have a head plugged it, just so you can test after waiting, but it is not necessary. The older units do not automatically discharge by flashing the strobes like the the newer ones. Rather they have a some internal means to discharge it to a safe level.

They were very helpful and friendly.

[neil poulsen]

OK... I powered one up it worked fine.... but the the Photogenic online info on this product says to keep the capacitors 'formed' the unit should be powered up every 60 days... these units have been idle for 5 years. I love the groovy retro look of this equipment... but am not interested in garnering a Darwin award... is there some kind of 'electrician' that can look at them and tell if they are safe to use.

Oh... and how does one 'discharge' the unit... I just popped the flash and unplugged it. Is the unit now sinisterly waiting to blow up in the middle of the night?

I haven't powered up mine for a while. At the advise of a Dynalite technician, I form my packs by powering them through four high wattage resistors connected in parallel. I forget the actual resistance and wattage, but the effect is to slowly build the potential difference. (I'm away from home.) It seems to work just fine.

In my case, the resistance and wattage is appropriate to two used M2000 packs I bought from Dynalite.

[Discoman]

if the unit itself is safe enough, the only main danger is to digital cameras. these old flashes can easily kickback 250+ volts through the sync. current digitals can handle at most 6 volts. camera cookin'

[marcojoe]

I have had all kinds of strobes in my studio over the years. I even had 10 Ascor high volt-age capacitors which drew 800ws each. Along with 4 heads and 1 sun head, the floor would shake everytime we fired it. But with shooting 8x10 Ektachrome, working at f64 was a advantage.
The Balcars and Speedatrons at 2400ws was no problem. Just remember to discharge the unit and head at the same time you turned off the unit. Never add or take off heads with the unit on. Make sure you charge the unit if it has been sitting unused for a month or two.

[Bob Salomon]

I have had all kinds of strobes in my studio over the years. I even had 10 Ascor high volt-age capacitors which drew 800ws each. Along with 4 heads and 1 sun head, the floor would shake everytime we fired it. But with shooting 8x10 Ektachrome, working at f64 was a advantage.
The Balcars and Speedatrons at 2400ws was no problem. Just remember to discharge the unit and head at the same time you turned off the unit. Never add or take off heads with the unit on. Make sure you charge the unit if it has been sitting unused for a month or two.

WS is a measure of storage not how much energy it draws.

Even after the flash is discharged a capacitor can still have enough energy stored in it to make you very hurt, or dead.

[Greg Blank]

Bob

Sorry to differ, WS is output as energy discharged not storage...storage is a rather simple term for capacitance, typically measured in Farads or portions of them.

You are completely correct that capacitors can have abundant energy to kill you after a single discharge. Most flash power packs don't completely discharge with a single flash and the pack itself is drawing back the voltage it needs for the next firing in milliseconds that is say a 1,000 volts for your typical 1,000 WS "capable" pack. (or somewhere above the rating of any given power pack) & faster than household breakers can trip.



WS is a measure of storage not how much energy it draws.

Even after the flash is discharged a capacitor can still have enough energy stored in it to make you very hurt, or dead.

[Don Dudenbostel]

As pointed out the big danger is old internal wiring and unplugging a head while the pack is on and creating an arc which can destroy the plug , pack and you. I've used Speedotron black line for decades and never had a problem but I never unplug heads while the unit is on. For years I had Norman packs and heads along with the Speedo and had many problems out of the Normans. Power / high voltage diodes blew from time to time creating a large ball of fire and a bang like a shotgun being fired. I updated my Speedotron lights a few years ago and sold about fifty thousand wat seconds of packs and heads. Some were newer 4800 and 2400 ws units and a few were the old 2401 packs. A local fellow bought one of the 2401 packs and somehow managed to totally destroy it. I spoke with Speedotron about how the incident could have happened and they had no idea other than creating an arc in an explosive atmosphere. Apparently the pack arced creating a powerfull explosion in the pack. The case was balooned and totally seperated the upper and lower half and ripping the screws that held it together out of the holes. the bottom of the pack was rounded where it would not sit flat and a hole was melted in the side of the pack. When the pack blew apart one of the conectors on the pack was blown to pieces and the upper part of the pack went up like a rocket and cracked a 2x4 in the ceiling above the pack. In forty three years I've never seen anything like this and neither had Speedotron.

I think many of the stories of dangerous strobes come from the days of the old Ascor Sun Lights. These were very high voltage units with piggy back capacitor banks that could be coupled with cables and could achieve extremely high output with very short durations. These units were very unsafe and photographers lost their lives not exercising good safety practices. I've not seen any of these units in the last thirty of forty years and would imagine they are totally out of service now.

Generally old strobes are safe but like any other electrical device caution and good sense need to be used.

[Daniel Unkefer]

I have older Broncolor strobes (two 606's, 404, 1400), older monolights, on down to an Impact system. I feel pretty safe using all of it, I am very careful with the big stuff.

[Bob Salomon]

I have older Broncolor strobes (two 606's, 404, 1400), older monolights, on down to an Impact system. I feel pretty safe using all of it, I am very careful with the big stuff.

Wish you had not said "older" I was the Sinar, Broncolor, Foba, Ademco rep for the USA when the 606 was introduced in 77 or so. Doesn't seem that long ago!

[emmett]

It's what Frank says about the arcing problem with old strobes. I believe that Dynalites were the first strobes that were protected from this. Back in the day I arced out an old Thomas Strobe unit and almost killed myself. All the connecting pins in the pack and the head melted. Old timers still turn off power packs when they plug in and unplug heads.

Just as an aside, I worked for a guy who used Norman strobes and the pack, for some reason, discharged the power through the sync cord and into the camera and into him. It stopped his heart and almost killed him.

I used to work with Dynalites in the 70s and they would frequently sizzle, pop, smoke and blow up. I always turned them off and bled them before pulling the head cables out. They would arc, at least the early ones did.