625A Battery Source

[bsharpe411]

The 625A produces 1.5v, and is therefore not suitable for the unmodified F-1, FTb, etc. However some cameras

designed for the PX625 @ 1.35v have been modified for 1.5v use AND those of us who have the Canon EF know that

camera can use 1.5v because of a built-in regulator.

 

Anyway, what I'm getting to is I have two EF's which have an appetite for batteries, especially when you forget to

shut down the meter. My local Radio Shack charges about $7 per and it was getting expensive. I checked out

the "Evil Auction" site for the batteries and found a guy selling that @ $5 for 40 (yes, forty) + $4.50 shipping. The

batteries expired in 2006, but I got mine today and popped in 2 into the EF and it's working fine. So for a bit more

than the price of one local battery, I've got enough to last a good long time.

 

I'm passing this along because he has several similar offers going on now and some of our EF loyalists may want to

take advantage. His id to 'toyman911'.

[User_502260]

I don't remember whether I got mine from B&H or from Freestyle but they were made in China. I also got them for an EF. If I only used the EF I would probably just get two MR-9 adapters and use the silver oxide MS-76 or the 386 cell from C.R.I.S.

[awahlster]

Jeff the EF has an internal voltage regulator and can use the 1.5V cells no need for any kind of adapter.

 

I too have bought button cells for pennies apiece off eBay I use a small LED flashlite when we pave roads at night to see the connections between the dump truck and trailer I drive. And the cheapee's from eBay last as long as the ones I store bought.

 

Granted you need to be careful who you buy from but they are a good source for small batteries

[bsharpe411]

All 40 of mine are blister-packed Duracells

[walter_degroot]

unless the manual suggests alkaline cells, they will give incorrect exposure,

yes a " bridge circuit" or a regulator circuit is necessary.

 

" regulator circuit" is more or less a wrong description'

as it requires a higher battery voltage.

a drop across a semicunductor junction is from 0.4 to 0,6volts.

if you start out with 1.35-1.5-1.55 volts, you don't have much to play around with.

a solid state voltage regulator IC may have as many as 20 transistor (equivalents) inside,.

 

so a tiny voltahge regulator IC can be manufactured, but physical laws prevent a regulator from managing a 1.5-1.55 battery to 1.35 v if that is what the camera needs to meter properly.

 

Most early cameras used a mercury cell that put out 1.35 volts, there was a cds photo cell

that was a LDR ( light dependent resistor) with adjustable resistors in the circuit to set for iso and f-stop this worked well. The mercury cell stayed constant over it's life of about 2 years and at the end died abruptly.

 

the silver oxide cell works the same way but starts at 1.5-1.55 violts..

a "shottky diode" has a fixed drop across the junction, and when inserted inside the camera

converts the camera to use silver-oxide cells, slight recallibration is often necessary.

 

almost all older cameras us a "series circuit" that is totally dependent on a cell with a fixed and stable voltage.

 

exceptions are some of the spotmatics that use a "bridge" or ballanced circuit.,

and are far less depentent on a fixed and stable cell voltage.

 

alkanine cells start high and gradually decline., there is no point in their life

when the voltage is stable.

if you say " what do you mean alkaline cells work fine- you are wrong"

try a roll of slide film. cry a lot. color print film is very tolerant.

but still the wrong exposure will cause less than perfect results.

durqacell and energizer LIED when they offered alkalines as " approved replacements" for mercury cells.

either they were very stupid of they didn't care.

 

That said, I like the P&S cameras that use a pair of aa alkaline cells.

long life and trouble free, but the cameras were desiged for this.

[User_502260]

I know you can use alkaline 625 cells in an EF. That's what I have in my EF now. The problem is that even A625 cells are not that easy to find locally. The MR-9 is more of a size adapter than a voltage adapter for an EF. By being careful about turning off the meter my A625 cells have lasted a long time. I heard years ago that the MS-76s in a Nikon FE don't last long. I have two FEs now and if I remember to turn off the meter this isn't a problem.

[razondetre]

I used to get mine at the Ace hardware. But the last two on the shelf said "use before 2006" and they don't seem to be carrying them in future. Porters.com has them though at not too bad a price.

[mark_e2]

I've been very unhappy with the A625 (I have not only F-1's but Luna Pro and Sekonic Combi Pro light meters as

well. I am getting good service by buying one of the zinc-air cells (by Wein) for each PX625 I would have used.

When they die, I press off the metal ring with my fingers and insert a 675 hearing aid battery (also zinc air)

into the ring. These are 1.4v and sell for about $6 for eight. They last as long as the Weins and my meters

match my camera match my Luna Pro-F. Removing the battery when not in use and covering the air holes with tape

seems to extend their life as well.

[vincenzo_maielli]

I solve the battery problem in my Canon F-1n (1981) and Canon FT-B QL (1974) with a Kanto adapter. This device, which work perfectly, employ a micro electronical circuit that automatically reduce the 1,55 voltage of the 386 silver oxide battery in the original 1,35 voltage of the PX625 mercury oxide battery. The Kanto adapter, that i strongly recommend, is available on www.smallbattery.company.org.uk or www.criscam.com

 

Ciao.