Super Graphic Electronics Question

Discussion in 'Large Format' started by henry_finley|1, May 20, 2020.

  1. My question has to do mostly with battery life. The Super Graphic has no on/off switch. So that means it is entirely dependent on capacitor quality to keep the batteries from being bled down in a short time. Speaking as a radio hobbyist, I don't believe I've ever seen a capacitor I would trust to have zero leakage. I have cut electrolytic caps open. I understand their construction of 2 rolled up foils separated by paper. I understand all that. But capacitors leak anyway, even brand new. All that said, I would very much like to order a set off 22 1/2 V batteries for my Graphic, but I don't want to install them, just to use the camera occasionally and have them to be dead the next time. I'm perfectly willing to open up the camera and install brand new capacitors. But what good would it do? As soon as I put 2 new batteries in the camera, the caps will charge up and bleed down slowly till the batteries are dead. That's my thinking. Unless someone would care to enlighten me. Thank you.
     
  2. You could either fit an on-off switch or remove the batteries after each session.
     
  3. The battery is only used to fire a flashbulb, right?

    So unless you're a reincarnation of Weegee, I don't see any problem in keeping the battery out until it's actually needed for a flash exposure.

    Or you could replace the wet-electrolyte capacitor with a modern low-leakage polyester one. The capacitor is only there to provide a brief burst of high current to ignite the flashbulb filament.

    If you don't use flash at all, you could remove the synchroniser, if fitted, completely.
     
  4. Thank you. Now that we've covered the 2 replies I knew I'd get, hopefully there will be more posters. 1) taking batteries out or installing a switch is not something I'd be interested in. 2)The batteries have nothing to do with flash. They power the shutter trip solenoid only. Thank you.
     
  5. I wouldn't leave batteries in anything I cared about just because of the leakage issue. The manual for the camera even tells you flat out not to do this. They seem to leak randomly these days, any brand and any discharge including zero. I don't know the value of the caps, but a true low leakage cap just isn't going to be an issue. Maybe Nichicon KL series? There are probably others. The leakage of even non-low-leakage caps should be extremely low after they've been formed for a while.

    IMO, the intrepid radio amateur would whip up a simple boost circuit using any of the suitable modern chips and use a more standard (and cheap) battery, sensibly removing it when not in use. There might also be some clever way to arrange a "power switch" in the form of a reed relay tube and external magnet that you move to close it. No holes or mods required.
     
  6. "Intrepid radio amateur". That's a good one. Actually I am very good with radios. I can restore them and get them in fine working order. and you ought to see my reel to reel tape recorder work. But alas, I am not trained and can't do something as rinky-dink as designing a new replacement for the original electronics of this camera. For one thing, since it takes 2 batteries at 22 1/2 V, I would assume it is a 45V solenoid. But why would Graflex have put in a 45V solenoid when ordinary Graphics just had a 6V one on the lensboard? And it didn't even have capacitors. It just took the 6V from the batteries straight to the solenoid. Why are those capacitors even there at all? All those questions aside, I have experimented and discovered that the Super Graphic battery compartment can hold 4 AAA batteries in the same space that the 2- 22.5V ones occupy. So, why can't i just solder up a little Eneloop pack with 4 AAA's? Then all I'd have to do is design a little op-amp circuit or somesuch that would kick up to 45v. If I took the original guts out of the body, certainly such a circuit could be fit in that space. But I have's a clue as to how to design one. Of course I'd still need a switch. But with some little pieces of wood from my RC airplane parts, I could fashion another battery compartment cover with a little slide switch of some kind mounted in it. But back to the circuit. And i'm clueless how to design it.
     
  7. But the solenoid has everything to do with the flash. It's a synchroniser that pulls the shutter release while simultaneously firing a flash. It's totally not needed to trip the shutter, which can be done digitally (using a finger) or with a bowden cable type release.

    The solenoid was specifically designed for use with old shutters that had no flash synchronising contacts built in, and was, I believe, an 'aftermarket' attachment.

    If you insist on using the synchroniser solenoid, then the suggestion to pull the batteries between use, or fit a switch, seems like the logical solution. I'm not sure what other answers you were expecting. A solar-powered charger perhaps?

    BTW, you can buy voltage boost circuits ready built from ebay and the like. They cost about £3 and are the size of a postage stamp. You couldn't buy the individual components for that price. But without a switch, your voltage multiplier circuit is still going to permanently use power.

    Then there are miniature 12v alkaline batteries, about half the size of a triple A cell. They cost peanuts, even for four of them.
     
    Last edited: May 20, 2020
  8. Thank you for these answers. This is a project that I worked at approx 3 or 4 years ago and put aside, leaving the camera in complete working condition as it was. Some of these ideas have refreshed my memory. I DID order a Chinese made circuit board, but when it got here, I saw it was too big to fit the space available. So I abandoned that idea and bought a used solenoid from an ordinary Speed Graphic lensboard. The idea was to convert the Super Graphic over to the old style Speed system. The solenoid was a hair too big to fit in the space where the Super Graphic solenoid is. But with a small amount of grinding on the lower part of the solenoid, I could make it fit. This is where the project was put aside. But the idea was to bypass or remove the original Super Graphic electronics and simply solder up an Eneloop pack of AAA's for 6V and go straight through the red button on the camera to the solenoid, with no electronic parts at all. Obviously with 4 AAAs I would have very little capacity, but at least I could recharge. I never planned on a full day of negative shooting. Now ready to pick up where I left off, I believe I recall my original question that I never sought an answer for. "Why does the Super Graphic have capacitors" With that question answered, I can proceed or abandon the idea. Are the capacitors there to give a big kick of juice to the solenoid to insure its dependability? Or, are they there to simply at as a switch to keep the batteries from being bled down? Remember, the red shutter trip button is NOT on the battery side of the capacitors. It is on the other side of them. This means that good strong non-leaking caps are all this camera has to keep from bleeding down batteries.
     
  9. I'm guessing, without knowing the circuit, that a battery doesn't have a low enough impedance to really kick the solenoid. The capacitors provide the current pulse. That said, it takes quite a lot of capacitance to accomplish anything useful in that department. I like the Eneloops a lot, if you can use them. They hold their charge for a long time. Here's another crazy idea. I know nothing about the solenoids, but could it be possible to rewind one to operate on lower voltage?
     
  10. Now you hit on something. Back then the Graflite flash unit on the regular Speed/Crown cameras was used to trip off the lensboard mounted solenoid, which was 6V plus or minus. Graflite had no capacitors that I am aware of. So instead, the special Photoflash batteries provided that kick. Back then there was ordinary carbon-zinc flashlight batteries, and Photoflash batteries. Everybody knew carbon-zinc was unsatisfactory. You HAD TO HAVE "Photoflash batteries". That was the only thing that provided enough kick to set off a flashbulb. And probably the only thing that would trip the solenoid. The 22 1/2V catteries were NOT photoflash batteries. Without capacitors, they would have been too undependable to reliably kick the solenoid to trip the shutter. The Super Graphic was totally new camera technology at the time. Now, in 2020, there is no such thing as a Photoflash Battery. Nothing made today can give that kick. Modern batteries simply can't unload their juice in a big enough kick. So Graflex decided on 45V plus a capacitor when they designed the camera. Back then every drugstore has 22 1/2 V batteries and tons of 4x5 film to boot. And there was no such thing as AAA batteries. So a 6V system was not feasible, given the space available in designing the camera. And 9V was only just being invented. I believe that's why they did the 2 x 22.5 + capacitor system. Dependability, capacity, and "kick".
     
  11. No, in the case of the bare Super Graphic it's for a body-mounted shutter release. Anyone who has used these cameras knows that the trigger is convenient when focusing with the right hand.

    On the Super Graphic the solenoid is not external. It's not even on the lens board. There's nothing sticking out and no wires showing. No muss or fuss; you just press the little red button and the shutter trips. If you have another lens (mounted on a Super Graphic lens board) you just swap lens boards and the little red button will still trip the shutter.

    Now, if you DO use a flashgun there was a special Y-cord for the Super Graphic. One end plugged into a 3-prong connector on the camera body; the other end split into two connectors that both plugged into a Graflite flashgun.

    With this configuration you could use the flashgun button as a trigger. If you use a flashbulb then the flash and shutter both fire. Without a flashbulb it's still a convenient way to trip the shutter. My memory is fuzzy, but I think that pressing the red button would also fire both the flash and shutter (one of the "Y" cables was plugged into the "remote" or "external" outlets on the flashgun?).
     
    lance_blakeslee likes this.
  12. Hi, I grew up using flashbulbs with Graflex-type flashguns, and never had any problems, that I know of, with standard batteries.

    Having said that, my first camera was a TLR (used Voigtlander Brillant) with no flash sync. I later had an accessory solenoid that threaded into the cable release socket along with a two-cell Graphlite. Now, with that, I always did an exposure test before wasting a roll of film and flashbulbs (I was a kid with little money to throw away, so I'd unwind the roll of 120 film, clip off a frame, more or less, then rewind the roll and stick the piece of film in the back of the camera. Then shoot a test shot, using the guide number for that exposure time, and develop in a tray.)

    I never had any exposure problems with Speed Graphic, etc., and the three-cell flashguns.

    I had always assumed that the Brillant solenoid adjustment was responsible for timing/exposure variations, but in retrospect, perhaps the state of the batteries was affecting the light-off time for the flashbulbs. Who knows, at this point? When I finally encountered electronic flash, whoa! The price of flash pictures went way down.
     
  13. Ever since I was a kid in the flashbulb days, I always remembered reading what I wrote above. Further, I build model rockets, and Estes always said photoflash batteries were needed in their launchers. I found it to be true myself. The best interpretation I can relay is that photoflash batteries were capable of pouring out the juice in large quantities quickly compared to regular carbon-zinc. As an aside, they corroded like crazy. Now we're discussing capacitors in the shutter trip circuit of Super Graphics. So everything adds up. So far as the above post, I would think that solenoid timing consistency could be very related to battery condition.
     
  14. Yes, I was unaware of that model of Speed Graphic that used a solenoid for the body release. Graflex cameras aren't that common in this part of the world. I've now looked it up, thanks.
    What? Have you tried shorting out a NiCd or Nickel-metal-hydride cell? They're quite capable of delivering 10 amps or more... and that's only the AA size cells.

    All flash-bulb firing circuits of any repute used a capacitor across the battery to ensure reliable firing, and the most common battery used in them was the little 22.5 volt Zinc-Carbon block. As Conrad says, the internal resistance of those little layered things was too high to deliver more than a few milliamps without the voltage collapsing.

    Any chance you could tell us what value the capacitors in the Speed Graphic are? At least then we'd know what sort of energy level is needed to trip the solenoid. An indication of size might help too.

    I also grabbed a few capacitors out of my spares bin. With standard electrolytics, it looks as if the leakage is somewhere in the region of 0.5 microamps per microfarad for values up to a few tens of uF. And a higher working voltage gets you a lower leakage - i.e. you don't want to be using them close to their rated voltage. Tantalums seem no better, and perhaps even worse leakage wise.
     
  15. I was talking about consumer non-rechargeables. Of course the nicads could pour out the juice, but because of the lower voltage, would also require recalibration of the solenoid timing om Speeds and Crowns. Remember, I'm discussing the subject in terms of what was commonly available at the time of the particular cameras design and marketing. In 1955, there was no alkaline, AAA was brand new, no 9V, no transistor batteries, and nicads were practically unheard of. Back then there was C, D, 22 1/2 and lantern batteries of various kinds. Anything else was pretty exotic and not likely to be found in a drug store or dime store regularly. And buy the time the AAA was invented, the Super Graphic was moving on from the drawing board into production. For a long time i wondered why they made the dadgum camera to take 2-22.5 V batteries. But when you put the matter into the context of the age, it make perfect sense. In 1957, 22.5V batteries were probably as common as pipe tobacco, cigarettes, film, and flashbulbs. And probably very economical. At the time, it was a very dependable design for a PROFESSIONAL camera. Now, it seems archaic and absurd, without that context of the era to explain it.
    What I am seeking is a good way to make use of that same red button to trip the camera, WITHOUT modifying (ruining) the camera with drilled holes and knucklehead filing and the like.
     
  16. Sooner or later, Dan Fromm is likely to see and respond to this thread. If anybody knows anybody who actually updated their Super Graphic cleanly to use modern batteries, and could advise you, it would be him. You could also try sending a PM to his p-net handle dan_fromm|2.
     
  17. Orsetto, thanks for the plug.

    I'm sorry, but Super Graphics are out of my range. And I don't know any users.

    The OP can get better advice than I can give by asking his question on graflex.org or Large Format Photography Forum

    Out of curiosity, I looked in the Super Graphic user manual. It recommends Everready 412 and Ray-O-Vac 215 flat 22.5 batteries. No mention of photoflash. I asked google to find the batteries. 412s are still available. If I were the OP I'd buy a pair and try them out.
     
  18. Back in the olden days, these were photoflash batteries. Being 63 in 2020, I remember them. I don't know when they quite making them. I suppose it's been nigh on to 50 years.

    index.jpg

    s-l400.jpg

    s-l400-1.jpg
     
  19. There have been quite a few non-invasive suggestions so far. It seems all that's needed is a readily available and cheap replacement for the 22.5 volt batteries that will fit in the same space.

    I draw your attention to my previous mention of small 12v alkaline cells (type 23A). They're used in little remote control zappers and the like. Locally I can buy a pack of two for £1 UK.

    I'm pretty sure that two of them side-by-side would fit in the same space as one 22.5v layer battery, giving a close-enough 24 volts.

    Using 4x 23A batteries would therefore fit the brief of requiring little to no modification of the camera, while being readily available and cost-effective.

    Replacing the electrolytic capacitors would be a good idea anyway, since they tend to dry out and lose capacitance over time. The youngest Super Speed Graphic is nearly 50 years old now, and capacitor miniaturisation and longevity has improved vastly in the intervening years.
     

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