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TML74
27-Feb-2014, 10:15
I have just bought a shutter that looks like a packard shutter, but in fact it is not a Packard one. I have bought it without the power source that could (I hope) open and close the shutter and I wonder what would be the voltage to use it ? Is it 110 v or maybe less ?

Here is a link to see it...
http://www.ebay.com/itm/291068335804?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
Any advice or help would be really appreciated !

Thierry M.L.

goamules
27-Feb-2014, 10:38
I don't know that shutter, hope someone can tell you what voltage. Because I DO know solenoids. If it's made for say, 12VDC, and you apply 110VAC, you will probably shoot the parts across the room. I've seen it done, in my engineering days. If you want to experiment, try LOW DC voltage and see if you can get it to actuate. Like 5VDC to start.

TML74
27-Feb-2014, 10:45
I have tried 6 and 12 V and it doesn't work... So as the hole is very large and it is a bit hard to open it, I wonder If I need a bigger voltage ?
Maybe someone else can give me other information. Thank you for your answer, Thierry M.L.

William Whitaker
27-Feb-2014, 11:01
I wonder If I need[s] a bigger voltage

If it was intended for aerial work as suggested by the description, then possibly it was set up for 24vdc. If I had to diagnose this relic, I'd start by examining the plug connections and checking for continuity in the solenoid coil. It's odd that the shutter is hard to open. Perhaps it is dirty or gummed up. Don't just keep pumping more voltage at it.

Honestly there has to be an easier way to make a photograph.

Randy Moe
27-Feb-2014, 11:18
I have one similar but not exactly the same. I opened up the solenoid, without damaging it and the coil was marked 117 VAC. I applied the voltage and it was too weak to work. I have a thread on RC servo control of that shutter. However I am only achieving 1/2 second, also working on flash sync is by adjustable servo relay.

Randy Moe
27-Feb-2014, 12:16
Also, if the shutter itself is sticky, do not be afraid of taking it apart. These are dead simple, careful disassembly and cleaning will help. I just did that to a 4-1/2" shutter that had lots of rust under the outside felt and inside. These were made from plain steel sheet metal without paint or sealant on the inside surfaces. They do rust, don't get these things wet. Clean everything and use NO lube anywhere. Dry and clean only. Dry Molybdenum could be used at pivots but I don't think it is necessary.

Amedeus
27-Feb-2014, 13:23
Those shutters are indeed very easy to open, clean and re-assemble.

As for voltages, I have quite a few electrical Packard shutters of various origins and they either use 110-117VAC or 24 VDC.

The AC ones are easy to operate. For the 24VDC ones you need to find a power supply that can deliver 24 Volt at rougly 500-600mA. This has worked for all my shutters so far.

This one is nice in that it has a 5" opening ...

My largest electrical one has a 4.5" opening and works on 24VDC.

domaz
27-Feb-2014, 14:08
If you need a power source in the 5VDC - 24VDC range today's Lithium Ion batteries might be a good option. They can provide a lot of instant amps that a solenoid is likely to need in a fairly portable package. Just be careful you don't pull to many amps from them or over discharge them or they can literally catch fire.

Harold_4074
27-Feb-2014, 16:50
For high-current, short duration use like a shutter solenoid, a big capacitor is probably more reasonable than lithium batteries. For example, a 68000 microfarad, 25 volt electrolytic capacitor costs only about $10US, and will deliver far more current than any comparably priced power source. Of course, under load the power output drops rapidly, but this is just what is needed for a shutter solenoid--a big kick to get the blades moving, then much less current as the solenoid retracts.

goamules
27-Feb-2014, 18:00
If the OP bought an electronic device with no idea how to use it, you really want him to be playing around with high farad capacitors? This is going to get interesting.....sheeze. He needs to put it away and buy one with nice, safe, pneumatic actuation like the rest of us.

Garrett (former Navy Electronics Warfare Technician whose equipment had 4,000 volt power supplies).

Randy Moe
27-Feb-2014, 18:27
Yes, capacitors can be extremely dangerous. I always use extreme caution as I really don't know when they become dangerous, meaning by capacity.

It is the amps that kill.

Old motorcycle magnetos were always a shocking experience.

We do need to be careful what we advise.


If the OP bought an electronic device with no idea how to use it, you really want him to be playing around with high farad capacitors? This is going to get interesting.....sheeze. He needs to put it away and buy one with nice, safe, pneumatic actuation like the rest of us.

Garrett (former Navy Electronics Warfare Technician whose equipment had 4,000 volt power supplies).

Harold_4074
27-Feb-2014, 20:06
Garrett, the OP asked about a solenoid that is almost certainly line-voltage AC or low voltage (<24V). My suggestion is irrelevant in the first case, and, I think, pretty innocuous in the second.

We are not talking about photoflash capacitors here, much less Tobe-Deutchmann low-inductance multi-kilovolt pulse capacitors. In the grand scheme of things, a novice is probably more likely to be hurt with a big lithium battery (or even nicads or a car battery) than with a capacitor that stores less than 22 joules at 24 VDC. It's easy to get badly burned with the former, but unless you have a break in the skin or a pretty large area of skin wetted with electrolyte, you are going to have a hard time electrocuting yourself with a 24 volt capacitor. The current capacity is there, but the voltage to push current through the skin is not.

In addition to the risk of a lithium battery overheating, with any high-current battery there is the risk of a fire or burn from inadequate wiring and the absence of suitable protective devices. Hence the time honored advice to remove jewelry before working on an automobile--a wedding band can do a number on your ring finger if you get it wedged between the battery lead on a starter and ground.

Randy, I can give you a fairly good idea when they become dangerous. It's around 40--50 volts, usually, because that's high enough to produce a "sensible" shock. The size of the capacitor is less important at the low end of the voltage range, because if you can feel something, your reflex actions can lead to worse injury than the shock. Of course, if you are talking really big capacitors then arcing or simple resistive heating come into play, and if there are inductors involved then you can develop higher voltages through magnetic field collapse.

But this is a photography forum, not one on industrial safety. So I will point out that the energy storage in the aforementioned capacitor is comparable to that of a Swedish medium-format reflex camera held at about waist height. Isn't that why we all stick to large format? :)

TML74
28-Feb-2014, 10:01
Well If I could have found a 5" opening without electric shutter, It would have be the best choice but very large opening packard shutter are rare, and new they cost too much. I think of someone who may have the knowledge to help me, and hope I will be abble to use this shutter with my apo nikkor 1210 mm...
I undertsand that it won't be so easy to make it works... Well thank you for your advice, Thierry M.L.

Jim C.
28-Feb-2014, 10:56
If the solenoid is of unknown value why not replace the solenoid with a new one of known voltage ?
Should be easy enough to find a one that has the same throw when energized.

Randy Moe
28-Feb-2014, 11:16
That depends on duty cycle. I have been looking into just that and have not yet found one that does a 10 minute hold the shutter open for focus cycle and then works quickly for a 1/30th shutter speed. That's why I am trying RC servo control.

We both would appreciate any suggestion on a solenoid replacement.


If the solenoid is of unknown value why not replace the solenoid with a new one of known voltage ?
Should be easy enough to find a one that has the same throw when energized.

Harold_4074
28-Feb-2014, 14:11
Packard shutters are inherently bi-stable devices; you open them, and they stay that way until you close them. The "instantaneous" feature uses spring tension to give the brief opening but in a way they are still bistable, in that there is a stable "closed" state with the cylinder unpressurized, and another closed state maintained by pressure after the exposure. For the one Packard I use with the instantaneous pin, gentle bulb pressure will open the shutter and leave it that way, which is great for focusing.

The obvious way to have both functions is to use a solenoid or motor to drive an air cylinder, and either put a rubber bulb in parallel for focusing or arrange an intermediate "stop" position where the blades are open.

I arrived at the solenoid/cylinder solution because I wanted to be able to do long exposures and didn't want to hack the shutter(s) to put in dual solenoids. An early version of the resulting setup, with all of its electromechanics, looks like this:

111339

It ain't pretty, but it works. Presently, it also has two 68,000 mfd capacitors to buffer the battery, because the 12V gel cell becomes polarized pretty quickly by the large pulsed current draw. The solenoids are energized only to open and close the shutter, so the average power draw is very small. For focusing, I just manually shift the linkage to open the shutter.

The best solution, I suspect, would be to use a gearmotor with an eccentric to drive an air cylinder. Stop switches on a cam would allow either a full cycle for use with the instantaneous pin, or a "halt" at just the point where the blades are open. This would be pretty easy to rig, and would avoid the key problem with solenoids: the ratio of force between the beginning and end of stroke is pretty large, and it is the minimum-force point that dictates the current requirement unless you provide some sort of nonlinear force/position conversion (a cam or multibar linkage, for example).

goamules
28-Feb-2014, 14:13
Most of the photographers I hear from on forums can't calculate the lens speed from the focal length and apparent iris. Many ask how to cut a hole in a lens board. You want to talk about engineering an electrical shutter you're probably talking to yourself or a couple others. Without the proper background knowledge and test equipment no one will ever figure this all out. PM the OP and offer to make his shutter work, or skip it.

Electrical solenoids on LF shutters are a solution looking for a problem. Duty cycles, megajouls, and electron hole flow theory only matter to electrical engineers. Disable the solenoid spring and actuate the shutter manually somehow.

Or use this: http://www.youtube.com/watch?v=pb7OWlVYYRw

Randy Moe
28-Feb-2014, 14:39
Harold, I love this this design! Thanks for sharing!

I never would have thought of the air cylinder you did. We used to use air switching relays to hammer 100 PSI to actuate 2" water valves open and shut for elaborate cooling systems. We needed to switch from -40 degrees to 250 degrees quickly to thermal shock automotive engines. I was the plumber, not the programer, but I did do loop tuning.

Here's my rig, not quite fully realized. Right now it runs on 4 AA battery pack and it's programed to run one shutter cycle when I switch the power on. 1/2 second shutter with flash sync. If I switch the power on and off quickly it leaves the shutter open. The microswitch is not yet functional, I am hoping to program it to reduce actuation lag.

111342111343

goamules
28-Feb-2014, 15:14
You two need to watch the video I posted. It might give you some more ideas.

Randy Moe
28-Feb-2014, 15:39
What is your solution?


You two need to watch the video I posted. It might give you some more ideas.

goamules
28-Feb-2014, 16:05
Just put together a Rockwell system like the video describes.

Randy Moe
28-Feb-2014, 16:08
I know you use a hat, some us want to wear our hats.

Obviously at least 3 of us are working on the same problem, so helpful advice is desired.


Just put together a Rockwell system like the video describes.

Harold_4074
28-Feb-2014, 16:27
Randy,

If you have the skills to program a Basic Stamp or the equivalent and interface to a couple of solid state switches, I'd be surprised if you couldn't also put together the essential parts of the setup I use---the air cylinder, solenoids, and lever. I have since gone from a plastic syringe to a home-made glass cylinder with a graphite piston, but the original worked well enough. The rest of what you see in the picture I posted amounts to a finite-state machine implemented in industrial timing relays. I have a self-timer function, programmable open, delay and close intervals for the solenoids (to accommodate different size/vintage shutters) and both front- and rear-curtain sync. The most elementary micro controller could handle all of this in a walk. :)

Why make it so complex? Because I can, and it's FUN!

Randy Moe
28-Feb-2014, 16:45
Exactly, some of us enjoy learning and doing. Since 90% of any photography I do is studio or indoors, I need to use lighting, old Sol is simply not there.

I am not a programmer, but I tend to learn enough of anything to do what I want. This BaoFeng radio in my hand is an example. I have had a Ham license for 5 years and finally bought a radio. It does need programming...

I work on my Pi and will get Ardino soon enough. They will do anything I need, shutter wise.

That Rockwell, is simply too antiquated for this old man.


Randy,

If you have the skills to program a Basic Stamp or the equivalent and interface to a couple of solid state switches, I'd be surprised if you couldn't also put together the essential parts of the setup I use---the air cylinder, solenoids, and lever. I have since gone from a plastic syringe to a home-made glass cylinder with a graphite piston, but the original worked well enough. The rest of what you see in the picture I posted amounts to a finite-state machine implemented in industrial timing relays. I have a self-timer function, programmable open, delay and close intervals for the solenoids (to accommodate different size/vintage shutters) and both front- and rear-curtain sync. The most elementary micro controller could handle all of this in a walk. :)

Why make it so complex? Because I can, and it's FUN!

TML74
9-Mar-2014, 02:51
Well I have tested the shutter with low voltage then I increase them and found that the shutter work just fine with 120 V Probably it is a 110 V one. Iwill see now how to make it work just a short time and add a flash possibility... I have asked on the Galerie-Photo forum, they also told me not to do stupid thing in order not to finish like Claude François...
Thank you for your advice, Thierry M.L.

Louis Pacilla
9-Mar-2014, 08:06
What is your solution?


You two need to watch the video I posted. It might give you some more ideas.



Or use this: http://www.youtube.com/watch?v=pb7OWlVYYRw