Flash Design

I’m looking at ever ones flash set up and thought how bulky and awkward they all are.

Why doesn’t someone make a flash head separate from the flashes electronics and the battery pack. The battery and electronics could be mounted underneath the housing in it’s own separate

case much like some video camera housings use. This would give a better balance to the system and make the arms and flash heads much smaller and flexible. I think it would be a big seller, would you buy one ?

Marc

It's done like this for efficiency - Volts drop & power drain would significantly affect the performance.

I agree that most of the strobes are WAY to big and why I much prefer S & S Units or System flash in compact housings.

It seem to me their shouldn’t be all that much increase in resistance in a cord of lets say 3 or 4 feet, if so... It still would be possible to regulate the voltage slightly to off set the voltage drop if it had any significant increase in resistance. It’s hard to believe that if this was the only problem that it could not be over come with some ingenuity.

Marc

I think you could remote the battery if you wanted to, but the strobe electronics ought to remain near the strobe tube. I think Bob's point is that smaller strobes are frequently good enough and wouldn't benefit from the added complexity.

Usually with video lights the battery canister is either very negative or very bulky. You don't want either attached to your housing. Of course, the battery for a strobe would be much smaller.

A two piece strobe attached like the Ikelite strobe controller would make some sense. The battery would be isolated from the strobe head and controls could be much closer to the housing. I just don't think the advantages outweigh the increased number of seals that could flood. Others may see it differently. At least there would be less weight and drag on the ends of the arms.

Yes, your point is quite valid and a simple way around it is to have a bank of batteries as you suggested coupled to the strobe head by a substantial low-loss cable. However, all of the electronics need to be close to the point of discharge as the loss over a minute distance is very significant.

The ideal flash head in my opinion would be a Minolta 5600 system flash with a circular flash tube chopped up inside a tiny housing. Heat transferrence catered for by a circular heat sink fitted directly to the housing. Chopping the units up will allow for resiting of red focusing lights too.

mmmm!

Marc, I bought your old Ikelite cp5000 housing and camera...........love the way you reversed the handles to get closer to the shutter release........I want to do this to my wife's c4040 housing.............how did you get the spring pin out of the tray casting?

Karl

It seem to me their shouldn’t be all that much increase in resistance in a cord of lets say 3 or 4 feet, if so... It still would be possible to regulate the voltage slightly to off set the voltage drop if it had any significant increase in resistance. It’s hard to believe that if this was the only problem that it could not be over come with some ingenuity.

 

Marc

Another way apart from the expensive low-loss cable approach would be to use an IC voltage/current regulator system, this would ensure optimum operation criteria.

Thinking about it an L200 IC would do the job amicably. A 12V bank could be used and dropped by the IC circuitry to the optimum voltage required by the flash electronics, the IC would maintain this voltage too. This IC regulator circuitry takes up very little room. Although the LM200 would need a small heat sink it can be folded flat on its back.

I would recommend an Aluminium container for the strobe circuitry for heat sinking, this effectively reduces the need for a large airspace. The whole lot mounted on a sliding tray fitting snuggly into the housing.

1 charge should last a week!

This is a simple but effective circuit

Hi!

Nice idea. We're talking 400V. A flash in principle is a flash bulb, a capacitor that keeps the energy (at a voltage of about 400V) and a small transformer/step-up to charge it from the batteries.

Firing the flash means to get a current flowing through the flash bulb. You usually do it with a bit of higher voltage or an extra contact on the flash bulb. If you want to do TTL you need a thyristor to stop the current early.

The really big lump in the whole setting is the capacitor.

Separating the light head from the electronics means a cable that carries about 400V. You wouldn't want it to leak while under water?!

In general, higher voltage means a reduction in power loss. There are some other problems like capacity of the cable that might affect the flash timing.

It would be a nice experiment though.

Currently I use 2 video lights but I am experimenting on a strobe housing too. I love the ease of handling with the small halogen light heads. A bulky flash housing gives me the willies but I'm not sure if there's a way around.

Let's see ...

Helge ;-)=)

Helge,

This is just to trim the voltage from a 12V remote battery pack to the 6 or 9V required by the flash circuitry which will still be housed behind the tube.

As I explained in the begining losses would reduce the effectiveness or function of the strobe and it may take several minutes to recycle.

Bob

Hi!

Ok, if you just want to get the power supply separated, it'll be ok. I just think, that the capacitor is the really bulky part.

On the other hand, a larger power supply would shorten recycling times.

I know of some (dry) flashes which use 400V battery packs to speed up recycling. You carry the pack on a strap round your shoulder. It doesn't make the system lighter or less bulky but it speeeeeds up ;-)

Maybe re-thinking the whole concept of flash could result in better usage of space. Most flash housings seem to me as if they've got a spare tube left and stuffed all the junk in. Some optimizing could help for sure.

On the other hand, optimizing tends to get expensive sometimes. Lots of prototypes, tests etc. You may afford it if you produce a thousands of items.

That's not the case for uw-flaslights of course ;-(

Helge ;-)=)