Photoflash firing circuit

  • Thread starter Gordon Campbell
  • Start date
G

Gordon Campbell

Guest
Evening, all. I apologize if this is the wrong group to make this sort of
request, but I've run out of ideas.

I'm looking for a schematic of a circuit that will randomly fire a
collection of photo flash units.

I'm working tech for a play next month and we're looking to simulate
electronic arcing with the flash units. I can find dozens of timers circuits
to fire the flashes, but every last one uses a set time. I need random or
something approaching that. I've never seen electrical shorts that arced in
a set pattern. ;-)
 
Gordon Campbell wrote:
Evening, all. I apologize if this is the wrong group to make this sort of
request, but I've run out of ideas.

I'm looking for a schematic of a circuit that will randomly fire a
collection of photo flash units.

I'm working tech for a play next month and we're looking to simulate
electronic arcing with the flash units. I can find dozens of timers circuits
to fire the flashes, but every last one uses a set time. I need random or
something approaching that. I've never seen electrical shorts that arced in
a set pattern. ;-)
Click to expand...
Hi Gordon...

I very much doubt that I can supply the answer that you
are looking for, 'cause I'm not sure that I understand
the question :)

But, photography's been a lifelong hobby, so.... just
wondering if you've seen/considered strobe flashes.

What they do is flash in virtually instantaneous response
to another flash. So, if you set them (any quantity you
like) up in a room, then every time any single flash
fired all of the slaves would fire. Is that what you're
looking for?

If not, then they all have a "test" button. If they
have to fire independently, then you could perhaps
think about extending the test contacts, use that to
set them off with. Caveat: I'm not sure what kinda
voltage is switched; but if you like I'll be happy
to take one apart and check for you.

On the off-chance you haven't seen a slave, send
me an email and I'll be pleased to send you off a
pic of one.

Take care.

Ken
 
In article <ruw1c.16726$qA2.902904@news20.bellglobal.com>, Gordon
Campbell <gordon_no_spam@cruachan.ca> writes
Evening, all. I apologize if this is the wrong group to make this sort of
request, but I've run out of ideas.

I'm looking for a schematic of a circuit that will randomly fire a
collection of photo flash units.

I'm working tech for a play next month and we're looking to simulate
electronic arcing with the flash units. I can find dozens of timers circuits
to fire the flashes, but every last one uses a set time. I need random or
something approaching that. I've never seen electrical shorts that arced in
a set pattern. ;-)

Just have a timer for each flash with a slightly different time. The
Click to expand...
flashes will run in a continuously varying pattern due to the different
flash rates. Will probably look OK.

If the timer circuits are based on the 555 chip, beware that the first
time period is longer than all the others. This might make cueing the
effect a bit difference.
--
Tim Mitchell
 
"Gordon Campbell" <gordon_no_spam@cruachan.ca> wrote:

Evening, all. I apologize if this is the wrong group to make this sort of
request, but I've run out of ideas.

I'm looking for a schematic of a circuit that will randomly fire a
collection of photo flash units.

I'm working tech for a play next month and we're looking to simulate
electronic arcing with the flash units. I can find dozens of timers circuits
to fire the flashes, but every last one uses a set time. I need random or
something approaching that. I've never seen electrical shorts that arced in
a set pattern. ;-)
Click to expand...
Little strobe lights could be used -I seem to remember from my Disco
installer days some little egg-shaped ones that screwed onto standard
light bulb sockets-, adjust every one for the slowest possible
frequency. The effect will not be random, but it will be a good
approach.
---
Ing. Remberto Gomez-Meda <gomerem@hotmail.com>
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.
 
The strobes can be triggered by using an SCR or relay in place of the
shutter contacts.

For a random sequence, how about using a PC to drive the outputs of the
parallel port in a pseudorandom sequence? There are plenty of BASIC
or other programs that will generate pseudorandom numbers. You can then
use them as the basis for delay or firing times, etc.

Probably a bit more complex than needed for a single production but it
would be fully customizable for the future.

Easiest would be to just have some extras firing the strobs manually. :)

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the feedback form on the S.E.R FAQ Web sites.
 
"Sam Goldwasser" <sam@saul.cis.upenn.edu> wrote in message
news:6wznawsgmk.fsf@saul.cis.upenn.edu...
The strobes can be triggered by using an SCR or relay in place of the
shutter contacts.

For a random sequence, how about using a PC to drive the outputs of the
parallel port in a pseudorandom sequence? There are plenty of BASIC
or other programs that will generate pseudorandom numbers. You can then
use them as the basis for delay or firing times, etc.

Probably a bit more complex than needed for a single production but it
would be fully customizable for the future.

Easiest would be to just have some extras firing the strobs manually. :)

--- sam
Click to expand...

I like Sam's suggestion, but I want to add one more to the heap. Get a
schematic for an old-fashioned color organ. Google for color organ
schematic and you'll find several to look at.
They are driven by music, pulsing a set of lights in response to the music.
Build it and play with the sensitivity and filters that make them work. you
might also try different types of music to give you a random effect.
Actually, they are pretty simple circuits, and should be easy to build.
http://www.discovercircuits.com/C/color-org.htm
http://www.commlinx.com.au/schematics.htm

Color organs became somewhat popular during the disco period, and you might
be able to find a copy at radio shack if you can find a store that still
stocks electronic stuff.

--
Dave M

Never take a laxative and a sleeping pill at the same time!!!
 
you just brought back some long gone memories, those were cool! they used
to screw in the socket the the lighbulb into them, ceramic. would like to
have a few of those myself, very neat!
wolf
"El Meda" <gomerem@hotmail.com> wrote in message
news:naie409o0d5al1mfa62ppij31aqeflf95m@4ax.com...
"Gordon Campbell" <gordon_no_spam@cruachan.ca> wrote:

Evening, all. I apologize if this is the wrong group to make this sort of
request, but I've run out of ideas.

I'm looking for a schematic of a circuit that will randomly fire a
collection of photo flash units.

I'm working tech for a play next month and we're looking to simulate
electronic arcing with the flash units. I can find dozens of timers
circuits
to fire the flashes, but every last one uses a set time. I need random or
something approaching that. I've never seen electrical shorts that arced
in
a set pattern. ;-)


Little strobe lights could be used -I seem to remember from my Disco
installer days some little egg-shaped ones that screwed onto standard
light bulb sockets-, adjust every one for the slowest possible
frequency. The effect will not be random, but it will be a good
approach.
---
Ing. Remberto Gomez-Meda <gomerem@hotmail.com
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.
Click to expand...
 
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