Graflex.org

[Stilagrrl]

I have a Super Speed Graphic with the Optar 1000 lens/shutter on it. Everything on the shutter works fine and I've taken the advice posted here about being very careful with it. The problem that I'm having is that the batteries that trigger the shutter mechanism die after only a few short weeks, even if the camera isn't used. With the first set, I thought it was just a fluke. I monitored the second set and there was definitely a constant drain on the batteries until they too went dead.

So, I thought I had some type of short, but after investigating further, it seems that there is some type of capacitor in the system. What I mean by that is if I remove the battery cover and batteries, then press the shutter button, the little trigger latch still fires once more, albeit without much oomph. So, there must be power stored up somewhere in the system. If power is being stored up, then is that the source of my battery drain? I've looked all over my camera and there isn't a power switch any where, so am I supposed to remove the batteries when it's not in use? I've come up with a kludge for now, by installing a switch on the battery door that enables/disables the battery connection, but I was wondering what the right thing to do is. Any help would be appreciated.

Thanks,
Rachel

[t.r.sanford]

I'd expect there to be a capacitor in the circuit, to serve as a reservoir for electrons when the battery is a bit run down and the solenoid makes a sudden, brief demand for current. If there is, its dielectric may be failing, after all these years, and thus may be "shorting" the circuit in an unobtrusive, insidious way. Your kludge sounds like a very good idea to me (I'm surprised Graflex didn't provide an on/off switch), but you might want to locate and test the cap.

[45PSS]

The way this board rearranges spaces it it impossible to draw a diagram so here goes with a written:

Negetive terminal of battery is in series with a 2.7K ohm 1/2 watt resistor. Positive terminal of battery is a common leg(x) to upcoming components. The end of the resistor not connected to the battery is a common leg to other components and is labeled Contact B.
In parallel with batery/resistor is two 80mfd 50 working volt electrolyic capaicators, each caps positive end connects to positive battery leg(x), neg to resistor leg B. Zener diode is in parallel with the above components with cathode to positive batt. leg(x) and anode to one side of camera switch and is lableled contact A. The other side of camera switch is connected to resistor/cap leg B. Both legs of components form two of the bellows contact strips. Selonoid is in parallel with zener diode when lens board is installed. One side of shutter sync contact connects with selonoid leg to leg contact A. The other sync contact goes thru the third bellows contact and becomes contact C.
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While a picture may be worth a thousand words, a quality photograph is worth a million.



[ This Message was edited by: 45PSS on 2004-08-03 13:20 ]

[45PSS]

The circuit components are in the rangefinder housing left of the batteries. The bellows and back must be removed as well as the Flash indicator needle in the top to remove the rangefinder housing to gain access to the components. The switch you added is a good idea and I would wait until the circuit quit working completely before opening it up, its a PAIN!
Charles

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The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

[t.r.sanford]

Any chance of cobbling up a rechargeable battery pack of some sort?

[worldphoto]

[Stilagrrl]

Thank you all so much for the information. Charles, as always, you're a wealth of information and while I probably won't do anything now, I'll definitely save your message as I'm sure I'll have to do it eventually. I guess my switch is going to be permanent, so I'll get rid of the tape and use some epoxy.

T.R., your suggestion of building a rechargeable battery pack sounds interesting, I'll have to look into it. There isn't much space in the battery compartment (just enough for two 22.5V rectangular batteries), but perhaps some type of external system would work.

Thanks Again!

Rachel

[Les]

I looked into creating battery packs from NiMHi, LiOn, and the rest of the new generation batteries....

I never could get that much voltage in that small of space and have any kind of reserve power, so external packs are a must.

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"In order to invent, you need a good imagination and a lot of junk" Thomas Edison