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Reform capacitor in flash unit
Feb 11, 2014 04:13:53   #
CO
 
The instruction manual for my Nikon SB-400 flash says that the flash should be fired several times every month to reform the capacitor. The instructions for my SB-700 flash are similar but say it's to refresh the capacitor. Does anyone know exactly what that does? What can happen if you don't do it? I've been firing mine maybe every two months.

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Feb 11, 2014 05:43:21   #
Manglesphoto Loc: 70 miles south of St.Louis
 
CO wrote:
The instruction manual for my Nikon SB-400 flash says that the flash should be fired several times every month to reform the capacitor. The instructions for my SB-700 flash are similar but say it's to refresh the capacitor. Does anyone know exactly what that does? What can happen if you don't do it? I've been firing mine maybe every two months.

Capacitors that are not " reformed" every so often can die and fail to charge, However I fire studio strobes about once a year and have had no problems. My SB 800 had not been fired in over a year, installed new batteries and it charged right up, it took a few flashes to get it to charge to full power.

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Feb 11, 2014 07:09:12   #
Blasthoff Loc: Life halved NY and IN
 
In practical terms, although technically different, capacitor characteristics are in some ways similar to batteries. It would not be good to take a new battery out of your car and sit it on the floor of your garage for years without charging. You will find it degraded far more then if it was used continually. If you try to use an old photo flash that hasn't been used for a long time you might find that on first use it never completely charges as you can hear the high pitched whine while charging. Charging, discharging, charging cycles will "reform" the capacitor IF it hasn't be let to be too far gone. Capacitors CAN become "leaky" in that they will not hold a charge. ie, When charged flash can not HOLD a full charge and drains (without firing) to a point where it starts charging again, in which case you can consider it shot as it will just "eat" batteries. Exorcizing the capacitor regularly will keep the capacitor in top shape with minimal or no degradation. That is putting it in the simplest terms I can explain.

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Feb 11, 2014 17:39:49   #
CO
 
Thanks everyone for the info. I'll have to make sure I fire my flashes regularly.

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Feb 12, 2014 06:45:23   #
DaveMM Loc: Port Elizabeth, South Africa
 
I don't understand why Nikon use the term 'reforming'. This really only applies to old capacitors such as in old equipment which have deteriorated and need to have their voltage slowly increased to let the Aluminium Oxide insulation reform. You cannot do this when installed and in use - if the insulation has deteriorated that far and you apply working voltage the capacitor will fail with a big bang.

What Nikon are really saying is 'By using them regularly you won't let your capacitors deteriorate.' My practice is that any time I switch on my flash and don't use it, I let the voltage stay on the capacitor (i.e. don't fire the flash by using the manual switch). The slow leakage away of the charge helps preserve the Aluminium Oxide insulation.

See
http://www.vcomp.co.uk/tech_tips/reform_caps/reform_caps.htm and
http://www.qsl.net/g3oou/reform.html
for some information on reforming

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Feb 12, 2014 15:57:42   #
Brian in Whitby Loc: Whitby, Ontario, Canada
 
As I understand it refers to electrolytic capacitors. In this type of capacitor the resistive layer is a gas. When left for long periods of time the some of the gas recombines with the electrolyte liquid.
Reforming is accomplished by charging and discharging several times. The voltage applied and causes the electrolyte too form gas thus "Reforming" the capacitor.

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Feb 12, 2014 17:28:33   #
CO
 
Thanks to everyone for the great information. Everyone is very knowledgable about this topic. The two articles are very good

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Feb 12, 2014 21:46:23   #
Virgil Loc: The Hoosier State
 
Does this by any chance also apply to built-in camera flash?

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Feb 13, 2014 00:34:44   #
Brian in Whitby Loc: Whitby, Ontario, Canada
 
Virgil wrote:
Does this by any chance also apply to built-in camera flash?


Probably.

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