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cyberjunkie
4-Nov-2010, 19:57
Hi.
I just found on Ebay this Copal shutter:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120638087259
I have a shutter at home that t looks exactly the same!
I removed it from a very big reprocamera lensboard, with diaphragm scales and a huge bajonet attachment to exchange the lens.
Even the plug (with three pins) is the same, and on the shutter body there is the same engraving: D.S. Copal.
I am attaching a picture if the reader is too lazy to have a look on Ebay:-)

At first i didn't even know if it was for AC or DC, then i figured out that originally it should have taken the juice from a power adapter, so DC was more likely.
From the text of the auction i get that it needs 24V, while my guess was for 12V.
The simplest way to use it should be to find two rechargeable batteries with 12V output, connect them in series to get 24V, and use one of those pushbuttons used in electronics to control the length of the power burst with your thumb.
With a little of exercise, it should be as easy (or maybe as difficult) as operating those Packard shutter that don't come with the "instant" pin.
I can't foresee any possible problem, because the the rod that transmits the movement to the shutter blades has a spring, so when the electricity is cut the shutter should close by itself. That's theory, i'd like to get some input from somebody who actually did some experiment with this type of shutters.

The best thing would be to find some kind of DIY electronic project that would allow to control the timings.
It should be fairly simple for somebody who knows a little about electronic circuits, but i haven't found anything useful online.
Recently i have seen for sale a control box for Ilex Electronic Shutters, it's the first time i have seen such a device sold alone, but i don't have the slightest idea about its functionality and in which way electronic shutters made by Ilex were controlled.
In the end it didn't sell for too much, but my budget is too tight, so i refrained from buying something that MIGHT be useful (and that would require a 110V to 220V AC converter).
What's for sure: the D.S. Copal electromagnetic shutter could be a true lifesaver, for those (like me!) who own cheap process lenses in barrel... if there is some way to operate the shutter in a controlled and repeatable way :D

I have read somewhere that some electric shutters open and close the blades in rapid succession, when powered. That would make the manual release of the shutter a difficult task, cause only one time would be available, and the pushbutton should be operated very fast, to avoid multiple exposure!
Any first-hand experience with the D.S. Copal?

have fun

CJ

domaz
5-Nov-2010, 08:27
Making controllers for them is a little tricky because you have to provide an initial burst of high voltage power and then a lower voltage to hold the shutter open. This link (http://www.chemie.unibas.ch/~holder/shutter/index.html) details construction of a controller.

Jason Greenberg Motamedi
5-Nov-2010, 10:17
I have the same shutter, also pulled off a reprocamera. I showed it to my brother who is an electronic engineer, and he said that he could probably figure out how to run it and build a controller, but that it might take a while. Let me know if you figure it out, and if he ever gets to it I will let you know.

BetterSense
5-Nov-2010, 11:36
Making a controller would be a piece of cake. I would probably just use some small SLA batteries, some electrolytic caps, a darlington transistor or two, and a microcontroller.

Ernest Purdum
6-Nov-2010, 12:11
I don't think you can count on the solenoid voltage. I am away from home and don't have the info at hand, but my recollection is that they were available at different working voltages and perrhaps even either AC or DC.

I would try to find someone with a variable power supply to try it out.

The Ilex (and Compur, I think) high voltage opening and lower voltage holding arrangement is a way of reducing battery size for out door use. The DS Copal shutters (and similar shutters made by Prontor) were mostly used indoors.

cyberjunkie
7-Nov-2010, 05:22
I think that a test with a variable voltage power supply is the only way to go.
That way it is possible to find out which voltage opens the shutter, and at which (lower) voltage it closes.
I have contacted the talented technician who published on his personal site (http://www.chemie.unibas.ch/~holder/shutter/index.html) a project for controlling a Melles Griot electronic shutter (good also for Ilex).
He promptly answered my request for help, and gently provided a few basic advices.
The project he made is based on an integrate that isn't available anymore, other way it could have worked with some minor modification.
I guess i could be more than happy with a less sophisticated device, so a simpler solution could be the way to go.
I was given the advice to use a NE555 IC, a timer that could be used with a rather simple circuit. I have found some documentation on Wikipedia:
http://www.kpsec.freeuk.com/555timer.htm#monostable
The link refers to the "monostable" operation, that should be exactly what's requested to operate a shutter.
I have no experience at all about electronics, i even forgot the very little general informations i did learn at school. So if somebody with similar needs, and with some familiarity with circuits, can provide some help, it would be great.
Even better: a simple circuit, with a reference to all needed components, that could be made by any technician with a minimum of expertise.

I have seen many electronic shutters for sale on auction sites or forums (most of them sold without controller), and a few posts asking for some simple solution, so i'm not the only one looking for some help...


have fun

CJ

Jack Dahlgren
7-Nov-2010, 05:50
I think that a test with a variable voltage power supply is the only way to go.
That way it is possible to find out which voltage opens the shutter, and at which (lower) voltage it closes.
I have contacted the talented technician who published on his personal site (http://www.chemie.unibas.ch/~holder/shutter/index.html) a project for controlling a Melles Griot electronic shutter (good also for Ilex).
He promptly answered my request for help, and gently provided a few basic advices.
The project he made is based on an integrate that isn't available anymore, other way it could have worked with some minor modification.
I guess i could be more than happy with a less sophisticated device, so a simpler solution could be the way to go.
I was given the advice to use a NE555 IC, a timer that could be used with a rather simple circuit. I have found some documentation on Wikipedia:
http://www.kpsec.freeuk.com/555timer.htm#monostable
The link refers to the "monostable" operation, that should be exactly what's requested to operate a shutter.
I have no experience at all about electronics, i even forgot the very little general informations i did learn at school. So if somebody with similar needs, and with some familiarity with circuits, can provide some help, it would be great.
Even better: a simple circuit, with a reference to all needed components, that could be made by any technician with a minimum of expertise.

I have seen many electronic shutters for sale on auction sites or forums (most of them sold without controller), and a few posts asking for some simple solution, so i'm not the only one looking for some help...


have fun

CJ

There are a number of "pre-packaged" microcontrollers out there right now which include a microcontroller, power regulation, and programming interface and software. The Arduino is a good example.

http://www.arduino.cc/

Something like that is going to be a lot more flexible than wiring up a 555 timer and will be programmable to do a bunch of other things.

Using two of the ports, two transistors and two diodes you can easily trigger a high voltage pulse and then a lower voltage holding voltage of almost any duration you like. The circuit on the right side of the diagram on the site you are looking at would be what you would hook up to the microcontroller.

BetterSense
7-Nov-2010, 08:16
555 timer is one (old) way to do it. IMO, that's the way you would do it back in the '90s before good microcontrollers were cheap. For things like this, I use a microcontroller nowadays. I used Arduino for all my digital light meters and densitometers. Sparkfun.com is a good source for Arduino stuff.

cyberjunkie
10-Nov-2010, 11:23
555 timer is one (old) way to do it.

I use a microcontroller nowadays. I used Arduino for all my digital light meters and densitometers. Sparkfun.com is a good source for Arduino stuff.

I have already found references about Arduino and other programmable microcontrollers, that would be perfectly capable to do what i need, and much more.:)
Unfortunately i am in no way a programmer.
What's nice about Arduino is that it's open, and that there is a vast community of users.
My capabilities are very limited, so the only way out would be a stroke of luck, finding the solution already "pre-cooked" by somebody else!
What needs to be done is quite simple, even if you need a sync-flash (which i do not), so it should be a simple task, if somebody is a little experienced. Maybe there is even a chance that one of the forum user would choose tha tackle this problem, producing a ready-to-make project... who knows;)

have fun

CJ

BetterSense
10-Nov-2010, 11:29
A shutter-driving program should very simple to write. I could do it on lunch. I would be more than willing to write code for you, provided it stays open source. In fact, if this were a popular application we would write an Arduino library and submit it for others to use and modify. That's why I prefer using microcontrollers; the sky is the limit as long as it's open source. With some trial-and-error, a flash sync feature could be implemented handily, or intervalometer software, or a remote trigger, or...

Ernest Purdum
10-Nov-2010, 17:51
Before finalizing a design, I think it would be worthwhile to determine just how fast the blades can open and close. I wouldn't expect a very fast speed. These blades are large and comparatively heavy.

Jack Dahlgren
10-Nov-2010, 18:17
Before finalizing a design, I think it would be worthwhile to determine just how fast the blades can open and close. I wouldn't expect a very fast speed. These blades are large and comparatively heavy.

Why? The shutter is going to open as fast as it can open and a microcontroller based design should not be different if the top speed is 1/5 second or 1/500.

The microcontroller needs to do the following:

detect a button press or other signal
read the desired shutter speed (need some way to set this)
trigger the open solenoid (this is easily done by sending power to a transistor - the transistor switches on the power to the solenoid)
at the same time switch the hold solenoid (same basic thing, but another transistor)
Then it can shut off the open solenoid
Wait the allotted time
Shut the hold solenoid.

The software for triggering the shutter is really easy. The hardest part is deciding how you are going to enter the desired shutter speed (buttons, knob, pre-set, read a light meter...)

I know there are some examples of using arduino as a camera trigger, and I'd imagine they could be easily extended to include the open solenoid pulse.

BetterSense
10-Nov-2010, 18:42
Shouldn't be a problem to hack a one-button interface. This is what I came up with just now; only took me 2 LPs.


/**************
shutter
**************
/*A program to drive a solenoid-controlled photographic shutter.
2010 chaz miller, this software is licensed under the gnu gplv3
see http://www.gnu.org/licenses/gpl.html for details
THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR
IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE.
*/


/*
hook the shutter relay/solenoid up to pin 12, which will go high when the shutter is intended to be open,
and will be grounded otherwise. Hook trigger switch to pin 2 (I think) so as to ground the pin
when the switch is closed. To choose a shutter speed, turn on the microcontroller while holding
the button/trigger closed. The LED will blink 5 times. Press the button N times, where 2^-N is the
desired speed (ex. press 1 time for 1/2s, 2 times for 1/4s, 5 times for 1/32s, 9 times for 1/512s).
The LED will blink 3 times. The speed will be stored in memory until updated. Speeds over 9 (1/512s)
will act as "Bulb"/*/

#include "EEPROM.h"


#define outpin 12 //hook solenoid/relay to pin 12
#define button 0 //hook button to pin 2
#define fudge 0 //amount of time in ms tacked onto shutter speeds to account for opening/closing

long fired; //increments when user presses fire button
int spd; //the desired shutter speed as 2^-spd seconds

void setup(){

for (int i=0; i<14; i++){

pinMode(i, OUTPUT); //set all pins to output

}

digitalWrite(2, HIGH); //interrupt pin
delay(20);

if(!digitalRead(2)){

spd=buttonChooser(2,0,2000);
EEPROM.write(spd, 255);
}

else{spd=EEPROM.read(255);}

attachInterrupt(button, fire, FALLING);//create interrupt for trigger button, on pin 2 I think


} //end setup

void loop(){

if (spd>9){

if(fired){
digitalWrite(outpin, HIGH);
delay(10);
while(digitalRead(button)==0){
delay(10);}
digitalWrite(outpin, LOW);
delay(100);
fired=0;
}
}

else{

if(fired){
digitalWrite(outpin, HIGH);
delay((2^(-(spd))*1000)+fudge);
digitalWrite(outpin, LOW);
delay(100);
fired=0;
}
}


} //end loop

void fire(){ //will increment when you press the fire button

fired++;

}// end fire



/*
******************
buttonChooser(customized )
******************
Watch a button and return how many times it is pressed. Useful for
program input. Will wait for
additional button presses only if it has been less than timeOut milliseconds
since the last button press, or in case no buttons have been pressed, since the
function is called. Watches for low pulses by default.
*/


int buttonChooser(int pin, boolean state, int timeOut){

int presses = 0;
long t0, t1;
t1=t0=millis();

for(int i=0; i<6; i++){ //blink 5 timees

digitalWrite(13,HIGH);
delay(300);
digitalWrite(13,LOW);
delay(100);
}

while(millis()<t0+30000){ //emergency timeout loop....could be set to 1

while(!state==digitalRead(pin)){

if (millis()>t1+timeOut){ //this loop waits for button to change state, returns if it's not pressed

for(int i=0; i<4; i++){ //blink 3 timees

digitalWrite(13,HIGH);
delay(100);
digitalWrite(13,LOW);
delay(50);
}
return presses;
}
delay(5); //we are mostly waiting around for the button press here
}
//hurray button pressed
presses++; //count a press

while(state==digitalRead(pin)){
delay(5); //stall while button is held down
}

delay(5);
t1=millis(); //reset the countdown to zero for the next press
}

return presses; //only happens when explodage of the emergency timeout

} //end buttonChooser

Jack Dahlgren
10-Nov-2010, 20:57
I'd make the led flash for the amount of time selected. So you have some visual indicator of the speed.

Ernest Purdum
11-Nov-2010, 10:46
Jack Dahlgren, "Why" is to avoid a design which promises a faster speed than can actually be delivered.

Dan Fromm
11-Nov-2010, 12:57
Jack Dahlgren, "Why" is to avoid a design which promises a faster speed than can actually be delivered.Ernest, you are completely right.

Some years ago I bought an oscilloscope camera that had a #3 Ilex electronic shutter and a built in shutter controller. Its marked high shutter speed is 1/125. This was part of its appeal. Stand-alone Ilex shutter speed controllers' highest marked speed is 1/60.

The wretched thing's top speed is nowhere near 1/125. All of its speeds, including 4 sec., run much slower than indicated.

By the way, the shutter has just one solenoid. It opens the leaves and holds them open. A spring closes them.

Jack Dahlgren
11-Nov-2010, 16:44
Jack Dahlgren, "Why" is to avoid a design which promises a faster speed than can actually be delivered.

A single line of code in that routine will limit the speed to the fastest tested speed. For example the value of spd goes from 0 to 9. If you determined that 7 was the fastest possible speed you could add a line:

spd = min(spd,7)

then plug the device into your USB port, click a button and you are done.

The beauty of a microcontroller here is that you can have the speed be anything from the max tested speed up to a day - given you have a power supply to hold the shutter open. If that shutter can open and close in 1/1000 or 1/10 you are still using the same circuit and same design. You just change the variable.

And if you need to adjust the speed to compensate for it opening more quickly than it closes you can subtract a few milliseconds here and there either as an absolute number or as a percentage or the square root or whatever you can dream up.

Adding a photodetector onto it and a few more wires and lines of code, you could even have the thing self-calibrate itself. Trigger the shutter, start a timer when the light first hits the detector, release the shutter, measure when the light stops, compare the two intervals and adjust.