flashes and capacitors

As I understand it, the flash has the batteries, that charge a capacitor. The capacitor usually holds enough charge for 3-4 shots at full power. But I was wondering, could you take a flash, put in a larger capacitor without blowing everything up?

I want to be able to trigger more shots on each charge, and thought this could be a simple solution.

First of all, the flash power capacitor, by definition, only holds as much electricity as will be using in ONE full power flash discharge.

Second, you could put in a larger capacitor and get more light...that is how studio flash makers make a single model flash head, then connect it to a 500 w-s or 1000 w-s or 2000 w-s power pack and get 1x or 2x or 4x the light output!

One needs to keep in mind that the DISCHARGE RATE of the power capacitor may well be fixed to a certain rate, and only the TIME DURATION of discharge is what results in 'more light'. Changing the discharge rate might well blow out the flash tube or fry the circuits feeding the flash tube!

Simply swapping out for a larger capacitor is kinda reckless (and believe me, I am an expert at 'reckless' when it comes to stuff like this).
If you were to change the microfarad (uF) rating, you'd need to change the rest of the circuitry around it. Otherwise, your best bet for any capacitor modification is to only increase the voltage rating; if your cap is rated at 200 volts, you can put a 300 or 400 in there without any issue, as long as it's physically the same size. What you're doing, at this point, is reducing the operating percentage of the cap; for example, if a circuit is designed to run at 32 volts, the manufacturer is going to put the next most common value cap in there (35v). At that point, throughout its entire operating life that cap is going to be running at nearly 100% of capacity. If you increase the working voltage, then the cap is going to work significantly less hard to do what it does...resulting in longer life and more robust performance.

IF such a simple conversion were possible, don't you think that it would already be available as a customisation? Perhaps even as an alternate model direct from the flash unit maker - in the "Ours is bigger than yours" vein? As it's not available, there's likely to be a really, really good reason.

You start off with the premise that

It doesn't - as Wilt says, it only holds sufficient for ONE shot at full power with just a tiny reserve to accomodate manufacturing tolerances (usually ±5%, occasionally ±2% on rated capacity with the tighter tolerances really hiking component prices in some cases). Can't even start to imagine where you got the idea that it holds more power; that would imply that makers build redundancy into their units.

So - nice idea but it wouldn't work. If you simply want to increase the number of flashes then just use an external power pack. Easier, cheaper, doesn't invalidate warranty, doesn't fry circuits, doesn't blow the tube (and, oh boy, but those things are expensive to replace because of labour costs).

allright, then it was just a gross simplification on my side and misunderstanding. But I know better now. Thanks for the input guys

I'm wondering why? Do you need to shoot a sequence, or just want a faster recycling time for "normal" shooting?
If a sequence, some flashes allow you to dial down the output, which results in significantly improving the recycle time.

Caps are merely batteries that can discharge at a very fast rate. The circuitry which charges the cap contains a timed circuit which governs the amount of power that can be stored in the capacitor. So even if you did use a much larger cap it wont change much other then providing greater theoretical output capacity. Also your flash gun doesn't have the capacity to produce 3-4 shots at full power no way no how. It is possible to decrease the recycle time substantially but doing so at full power is a good way to cause a total meltdown.

If you have one of Canon's better flashes (580EX, 580EXII, 600EX) then they have the capability of using a CP-E4 external battery pack. This pack holds eight AA batteries and high voltage charging circuitry so it can deliver high voltage directly to the flash capacitor to charge it faster.

Years ago Armato Photo in NY ( and probably others) offered a modified Vivitar 283 with additional capacitors in the battery compartment. This increased the power to 100 or 200 W/S, (The Armatar-100 and 200) but since the battery compartment was no longer there on the 200 W/S model, an external High Voltage power pack was needed. Also, a Norman/Lumedyne/Quantu​m type of flash tube with socket/holder was needed to handle the extra power, and was mounted on the unit. You occasionally see these flashes pop up at auction. A quick search shows four of the available now, both the 100 and 200W/S models. Search on the auction site for Armatar.

Don't forget your physical issues of heat and size. If you were to go tinkering with things like this it is very easy to end up with a melted flash unit, if not an out right fire ball. (Exploding electronics is never a fun thing to be around. Trust me, I've blown up a coffee machine before, so I know what I'm talking about.)

What are your exact goals? It is possible to build your own flash equipment (which may be easier than trying to modify an existing product), but it is not an exceptional safe hobby. If you have to ask questions about high voltage electronics, then you are possibly not ready to jump into tinkering with them.

Phototeacher wrote in post #15430927
Years ago Armato Photo in NY ( and probably others) offered a modified Vivitar 283 with additional capacitors in the battery compartment. This increased the power to 100 or 200 W/S, (The Armatar-100 and 200) but since the battery compartment was no longer there on the 200 W/S model, an external High Voltage power pack was needed. Also, a Norman/Lumedyne/Quantu​m type of flash tube with socket/holder was needed to handle the extra power, and was mounted on the unit. You occasionally see these flashes pop up at auction. A quick search shows four of the available now, both the 100 and 200W/S models. Search on the auction site for Armatar.

I was about to mention the same.

IMAGE LINK: http://www.flickr.com/​photos/stu46/386438408​4/

Phototeacher wrote in post #15430927
Years ago Armato Photo in NY ( and probably others) offered a modified Vivitar 283 with additional capacitors in the battery compartment. This increased the power to 100 or 200 W/S, (The Armatar-100 and 200) but since the battery compartment was no longer there on the 200 W/S model, an external High Voltage power pack was needed. Also, a Norman/Lumedyne/Quantu​m type of flash tube with socket/holder was needed to handle the extra power, and was mounted on the unit. You occasionally see these flashes pop up at auction. A quick search shows four of the available now, both the 100 and 200W/S models. Search on the auction site for Armatar.

I've never had the 200W/S version, but I love the 283!
Simple "every-day-emergency" location lighting

Okay who owns an Armato modified Vivitar 283 and is also willing to open it up for some good old fashioned reverse engineering. I have a couple 283's that are begging to be modded.

I would pay/rent/buy If someone would be willing to send me one (working or not) for my own inspection.

stu46 wrote in post #15434008

IMAGE LINK: http://www.flickr.com/​photos/stu46/386438408​4/
Flash by stu46, on Flickr

Has anyone noticed that...

• the flash tube is totally different than the standard Vivitar and Sunpak, and
  
• the head design has been modified extensively to accommodate it, and
  
• the exposure of the Armato flash tube to the air allows it to dissipate a considerable amount of heat
  
• more light and heat produced by the standard Vivitar 283 flash head would probably overheat and melt things inside

Wilt wrote in post #15421622
First of all, the flash power capacitor, by definition, only holds as much electricity as will be using in ONE full power flash discharge.

Not true, there are a number of flashes on the market that only use a fraction of the stored power for a full power flash.

In the olden days yes once triggered the xenon bulb would not extinguish untill it discharged the cap to below the sustain voltage but that hasn't been the case for a decade or more now.

Wayne