Carl Vogt , Feb 10, 2001; 07:18 a.m.
The answer to your question ". I was wondering if it would be possible to retrofit these units with an electronic flash instead of a bulb. The answer is yes, but first you need to have a little information. Older Box cameras with flash bulbs only used M sync. The more sophisticated cameras often had a selector lever to switch from M to X sync.
M sync for flash bulbs ...shutters setting to syncronize the shutter for SLOW burning flash bulbs. Simply put, the contacts to fire the flash are closed the moment the shutter starts to open, thus the shutter would be fully opened when the light from the flash bulb hit its peak intensity.
X sync for Electronic Flash, there is a delay, the contacts are closed only when the the shutter is fully opened. This is because the Electronic Flash units fire VERY FAST often less than 1/10,000 of a second!!!
The problem is if you just hooked up an old electronic flash unit to the contacts on the camera and fired the shutter, the light from the flash would be gone before the shutter was fully opened causing a gross under exposure...
This problem can be fixed, assuming you are handy in basic electronics. I once set up a Polaroid camera to use electronic flash by having the shutter contacts trip a relay, which then fired the electronic flash. With some adjustment of the contacts,the relay provided the necessary delay required to achieve good exposures. A better apporach is to use an adjustable delay circut to provide the time delay (although a little more complex). A site to find a delay circuit is https://www.pacsci.org/public/education/gallery/high_speed_photos/nfpaper.html
With some experiments this circuit after getting the timing right should do the job. To check the timing, when you have the connections from the flash to the camera connected, open the back of the camera (with no film) place a piece of white paper on the film plane, point the flash at the lens look at the back of the camera viewing the paper on the film plane and flash the shutter, with out the delay the light will be dim but will be much brighter when the sync is correct. Try this with a camera with X and M sync first to see how it works.... Hope this helps Carl
Carl Vogt , Feb 10, 2001; 08:24 a.m.
Upon rereading your question, sounds like you also wanted to make an electronic flash unit. I recommend finding an older unit complete and ready to go. Often available cheap at flea markets, garage sales, etc. If you still want to create something, a Great source of information is https://www.misty.com/people/don/samflash.html
This site has tons of information, Including sources of parts. Please note the WARNING, electronic flash units use HIGH VOLTAGE if you are not careful you can get a serious shock from even small units.. Even though the flash is unpowered the capacitor can still holds HIGH VOLTAGE (300-500v) charge. If you understand Electronics and are careful a neat source of Free flash units is your local mini photo lab, you can often get a few used shingle use flash cameras to play with... READ SAM'S STROBE FAQS AT THE ABOVE LINK FIRST
Hope this helps, Please be careful!!!!!!!!