Canon LTM Substitute Capacitor

Canon M39 M39 screw mount bodies/lenses
kb244

kb244

Well-known
Local time
6:52 AM
Joined
Dec 13, 2006
Messages
623
Location
Grand Rapids, Mi
View My Gallery
So I got a Canon Flash Unit V by courtesty of Dexdog, as he said either the battery or capacitor is dried out or dead. Well the batteries I can get fairly easily since its the same as an Everready 505 22.5V for garage door openers and what not. The capacitor on the other hand says 100MFD 25WV, I assuming meaning 25 Watt-Volt (I guess since it wants 25W/V to fire the flash, but the batteries are only 22.5V it capacitates the power until it reaches the desired voltage for firing). Its basically a round metal cylindar loosely fit inside a black plastic encasing that it can slide out of easily with the Canon branding on it.

So I'm curious, are there substitutes I can rig to make this work. I know now days capacitors are probably smaller than they used to be, and I could probabably rig it to fit inside the enclosure and maybe wire an extension so that it can fill the length.

Any recomendations out there, I really don't feel like spending 25$ + 15$ shipping from some ebay store in montana with no garantee the capacitor works.

Though I should also probably just be patient until I purchase the battery, just in case the capacitor does work and just needed a new battery. But in case the capacitor is dried out, I'd like to hear some sugestions.

Will post pictures if desired.
 
Hi Karl,

kb244 said:
100MFD 25WV.
Click to expand...

This means 100 uF (micro Fahrad), 25 V maximum Voltage. You can replace it with a generic electro-lytic capacitor with similar spec that fits in size (from Radioshack, etc). When you put it in, watch the polarity of the capacitor.

Best,

Roland.
 
Last edited:
ferider said:
Hi Karl,



This means 100 uF (micro Fahrad), 25 V maximum Voltage. You can replace it with a generic electro-lytic capacitor with similar spec that fits in size (from Radioshack, etc). When you put it in, watch the polarity of the capacitor.

Best,

Roland.
Click to expand...

I guess otherwise I get quite a pop from the battery next to it eh.
 
100 MFD puzzles me, sounds like 100 µF capacity but the smalles capacitor for 25V I can find is 1000 µF, 10,000 µF capacitor for 25V is 30x40 mm.
 
It does seem small ... could be mF (milli Fahrad), but that's very big for back then ...
Can we find specs for the flash somewhere to verify ?

You can safely buy a capacitor for higher voltage (like 33V, or more).

Roland.
 
Last edited:


Does it look like this? Some 30x45mm?
 
Replacing like for like should be no problem, be carefull to ensure you get the same type, i.e Electrlytic (Polorised) or not. Electrolytic ones are nomally identified by + and/or - markings, or often a band of arrows pionting to the negative terminal.

The 100MFD marking is the capacity value, "100 Micro farads" again be sure to get the same value or higher here.
There may also be a voltage rating marked on it too, not the watts per volt but the actual rated voltage it can take.

Oh its been so long since i fiddled with old radios and such!😀

P.S Be very carefull of capacitors!!! They can Bite!
 
The plastic square that encloses the capictor cell shows - and + on either end, 100MFD 25WV and the Brand Canon.

Removing the Cell its a silver rod, with a protruding contact ( like a AA but with a + style end on both sides) , one end has a recessed collar or groove. The cell itself has a japanese logo on it, and the number 5605041

It's almost the exact same size as a AA battery with the plastic enclosure on it, just like the MV15 battery, except cornered off like the battery.
 
stumar said:
P.S Be very carefull of capacitors!!! They can Bite!
Click to expand...

I learned that as a kid taking appart a electronic flash unit in a disposable camera, seemed like the damn thing would not let go of my hand as I tried violently to shake it off.
 
Solder in an electrolytic capacitor with the same value, 100mfd @ 25 working volts. Note the polarity. Use a six foot wood broom handle to turn the flash on the first time ;-)
 
dogless said:
Solder in an electrolytic capacitor with the same value, 100mfd @ 25 working volts. Note the polarity. Use a six foot wood broom handle to turn the flash on the first time ;-)
Click to expand...

Flash does not have an On/Off switch, I assume its on the moment you put a battery in, since it only has a test button, and a eject button for the bulb.
 
Okie dokie change of plans, the local radio shack north of me has a M505 (2.5V MV15 replacement battery) for about 7$, and a 100uF 35v Axil-Leaded capacitor for 1.29. From what I read earlier as long as its higher than 25v, I should be ok. And just to make sure to solder positive to positive. I imagine the easiest way to do it, is to tape down the capacitor with electrical tape (as not to be freely suspended between the leads), then solder the ends to the contact. Also I am assuming that the collar groove marks where the positive end is?
 
greyhoundman said:
Usually yes. Also be sure to insulate the leads between the cap and the connection point. You don't want any possible arcing.
Click to expand...

Insulate, as in not to allow the leads to break off the ends of the capacitor? If I am understanding you correctly, try to keep the lead as straight as possible from the end of the capacitor to the contact.
 
I'll probably just use a tiny heat-shrink plastic tube for the capacitor + leads.

Also out of just sheer curiousity and boredom, I hooked up a digital multimeter to a fresh AA, the capacitor, and the original battery that came in the flash. And I Got the following.

Fresh AA - ~ 1.6v
Capacitor - ~ 40.6 mv
Old Battery - ~ .445v
 
You must log in or register to reply here.
Back
Top Bottom