SYCHRO COMPUR ELECTRIC

[Philippe-Georges]

I am looking for a solution for this shutter.
There are no more 4,5 V batteries made/sold for this shutter so I can't use this lens anymore.
Does anybody has an idea?

 

[AgX]

Just insert three 1.5V cells in series.

 

[gone]

Here's more than you need to know on Compur shutters, and S.K. Grimes would seem to be one of the leading experts on them. As mentioned, just use 3, 1.5V batteries, although Grimes mentioned there were replacements on the internet for PX21 batteries. Does your shutter work w/ a battery in it? He also mentioned that the majority of them didn't work.

https://skgrimes.com/products/shutters/compur-shutters/

 

[AnselMortensen]

Is it a #1 size shutter?
If so, and if it was mine, I'd put the lens cells into a Copal #1 shutter...same lens cell threads.
It would require new aperture scales to be made, however.

 

[AgX]

Why acquire a new shutter, new scales, and exchange it for the old one, when basically all the old one needs is a new battery?

 

[wiltw]

Exell Battery A21PX 4.5-Volt Alkaline Battery (White)

https://www.amazon.com/Exell-Batter...t=&hvlocphy=1013581&hvtargid=pla-837297237736

 

[AnselMortensen]

OP didn't specify whether it actually works with a battery.
According to the Grimes link, most don't.
If it were mine, I'd put the elements in a Copal & be done with it.

 

[btaylor]

I have one of these shutters. I found the correct battery somewhere on the internet like the one linked above. It works perfectly, the shutter speeds are more accurate and repeatable than my non-electronic shutters in fact except for the long (over 1 second) times. They are wonky but completely repeatable.

 

[AgX]

OP didn't specify whether it actually works with a battery.
According to the Grimes link, most don't.
If it were mine, I'd put the elements in a Copal & be done with it.

-) Based on its design I got not reason to espect them non-working. I got two such shutters.
-) As indicated substituting a shutter just because it has not got an escaspement, but is electronically controlled seems absurd to me. Even if it was dead I would rather consider a repair. Unless it is to be expected to fail again.

 

[Philippe-Georges]

Hallo all,
I found the solution.
As I needed 4,5 V to operate this shutter, I thought that 3x1,5V might do.
So I Googled for a battery holder for 3 batteries, and found something on Amazon.de.
It was an offer for a set of 5 little holders with a switch built in for less than € 10,-, which took about 4 days to be delivered.
With some phantasy and fiddling, it doesn't look that 'pretty', but it works as a good as could be, see the picture.
I opted for rechargeable AAA batteries as they have only 1,2V but a lot of Ampères, perhaps to much, and I was afraid to burn the electromagnetic resistors in the shutter mechanism.
What do you think?

The only thing I have to figure out is hou to attach that battery holder to the camera (a Linhof Kardan GT 4"x5"), right now I use a rubber band...

 

[abruzzi]

The only thing I have to figure out is hou to attach that battery holder to the camera (a Linhof Kardan GT 4"x5"), right now I use a rubber band...

A ruber band sounds like a good approach, if there is an easy piece to attach to. Slighly more pemanant would be to use velcro somewhere. I assume you might change out the lens for another at times, and if those lenses don't need the battery, I'd definitly want to quick to attach and quick to remove.

 

[wiltw]

With A21PX 4.5-Volt readily available at about $12, what was the point of the jury rig?

 

[Philippe-Georges]

With A21PX 4.5-Volt readily available at about $12, what was the point of the jury rig?

That battery might be available in the San-Francisco bay area but not in the EEC.
I saw two on the internet: one at Aliexpress and one on Amazon.com, which was'n available at the moment. Both weren't exported to the EEC nor to Belgium.
A specialised firm in the Netherlands (->EEC) couldn't provide anymore, neither could Schneider-Kreuznach, and I think that COMPUR doesn't exist anymore...

So, to quote Werner Herzog: "Jeder für sich und Gott gegen alle"...

 

[Philippe-Georges]

This is a good way to verify if the shutter works. A frequent seller on the 'Bay listed a 240mm lens in one of these shutters for months. I wrote her several times and could not get her to expend even a calorie on connecting some 1.5 volt batteries to test the shutter. Odd, as if she really didn't want to sell it.

The shutter works good, I can't check the speed accuracy, but I will assume that's allright.
According to a technician of Linhof I mailed with, these shutters are rather robust. Linhof used them in their Aerotechnika camera's and at a power of 6 V!
As aero camera's have to undergo an intensive use, heavy environmental changes like pressure and temperatures, and vibrations, I am confident.
The main reason I want to keep this shutter running are the long exposure times, this one goes till 32 sec.

 

[wiltw]

That battery might be available in the San-Francisco bay area but not in the EEC.
I saw two on the internet: one at Aliexpress and one on Amazon.com, which was'n available at the moment. Both weren't exported to the EEC nor to Belgium.
A specialised firm in the Netherlands (->EEC) couldn't provide anymore, neither could Schneider-Kreuznach, and I think that COMPUR doesn't exist anymore...

So, to quote Werner Herzog: "Jeder für sich und Gott gegen alle"...

Odd, I wonder what the reason for non-importation of a chemistry battery available in other Voltages. Perhaps testing or documentation (in all EU languages) or some other requirement. I know European models of cars are often not available in US for testing cost reasons.

 

[Philippe-Georges]

Odd, I wonder what the reason for non-importation of a chemistry battery available in other Voltages. Perhaps testing or documentation (in all EU languages) or some other requirement. I know European models of cars are often not available in US for testing cost reasons.

Most of the time in has to do with environmental regulations, public health and, last but not least, import taxes. Import from China, as Aliexpress is, is subject of a new tax regulation.
But, really, I wouldn't know for sure as things change all the time and sometimes getting overly complex.
Anyway, that shutter is firing well now.

 

[wiltw]

Most of the time in has to do with environmental regulations, public health and, last but not least, import taxes. Import from China, as Aliexpress is, is subject of a new tax regulation.
But, really, I wouldn't know for sure as things change all the time and sometimes getting overly complex.
Anyway, that shutter is firing well now.

But it is an alkaline battery!
4.5-Volt Alkaline
I looked up Exell company, and it is a US company that probably imports product from China. That could be the issue, that they have not attempted to enter EU market.

 

[reddesert]

Generally a battery will only supply as much current as the device will draw, that is the current draw is set by the device's internal resistance, not the battery's current capacity. Thus powering the shutter with 4.5V in 3 AAAs should not harm a device intended to run off a 4.5v small battery. You might be able to make a smaller battery by running it off a stack of 3x LR44 or SR 44 button cells. I bet if you could get an A21PX 4.5v battery and rip off the outer covering, you'd find 3 button cells inside anyway. Alkaline batteries are naturally 1.5v so higher voltages are made by wiring cells in series.

 

[Philippe-Georges]

Generally a battery will only supply as much current as the device will draw, that is the current draw is set by the device's internal resistance, not the battery's current capacity. Thus powering the shutter with 4.5V in 3 AAAs should not harm a device intended to run off a 4.5v small battery. You might be able to make a smaller battery by running it off a stack of 3x LR44 or SR 44 button cells. I bet if you could get an A21PX 4.5v battery and rip off the outer covering, you'd find 3 button cells inside anyway. Alkaline batteries are naturally 1.5v so higher voltages are made by wiring cells in series.

Thank you, Reddesert, for the enlightenment.
I had that impression too that there was no real problem with the Ampèrage of batteries, but as a shutter is so tiny and most (electronic-) camera's work with even small batteries, I was in doubt.
Anyway, with that capacity, this shutter might run fo ages...
I only have to take care the the batteries will not leak over time.

 

[grat]

A21PX is probably an American designation. I've also seen it called, I believe, A133 or 523. One site lists:

Cross Reference: A133, 523, PX21, EN133A, PC133A, V21PX, TR133A, 3LR50

And the last part tells me it's 3x LR50 cells.

 

[wiltw]

A21PX is probably an American designation. I've also seen it called, I believe, A133 or 523. One site lists:
And the last part tells me it's 3x LR50 cells.

I did some digging and found this information pertaining to the A21PX:

This 4.5V alkaline battery is also known as:
- V19PX
- 531
- 3LR50
- 1307AP
- RPX19
- A19PX
- EPX19

Used in older Polaroid Cameras Models: 100, 101, 102, 220, 225, 230, 240, 250, and 340
The PX19 battery is an uncommon battery found in older polaroid cameras. This 4.5V alkaline battery has snap terminals (similar to a 9V), with the positive on one end and the negative on the other.
Chemistry: Alkaline​

The mention of snap terminals is somewhat puzzling, since the Amazon ad battery does not have terminals.

 

[grat]

The fact that your cross-reference says it's also the A19PX leads me to believe you skipped a line, somewhere. The A19PX does have snap terminals, but the A21PX doesn't.

Varta, which appears to be a European battery manufacturer, does have a V21PX in their inventory, and it appears to be a 4.5V 600 mAh battery.

 

[Bob S]

The fact that your cross-reference says it's also the A19PX leads me to believe you skipped a line, somewhere. The A19PX does have snap terminals, but the A21PX doesn't.

Varta, which appears to be a European battery manufacturer, does have a V21PX in their inventory, and it appears to be a 4.5V 600 mAh battery.

Ansmann probably also has it.

 

[wiltw]

The fact that your cross-reference says it's also the A19PX leads me to believe you skipped a line, somewhere. The A19PX does have snap terminals, but the A21PX doesn't.

Varta, which appears to be a European battery manufacturer, does have a V21PX in their inventory, and it appears to be a 4.5V 600 mAh battery.

I did put in '4.5V alkaline' only, which probably accounts for A19PX vs. A21PX. Thx for pointing that out.

 

[Philippe-Georges]

I got a e-mail from Linhof and they still have a few PX21 batteries left in their catalog under number 022 506 for € 38.- plus shipping.