Olympus OM-1n exposure meter conversion

[koraks]

I did a quick search on "px625 adapter" on Aliexpress and got many hits showing what looks like a machined brass insert that takes an LR/SR44 cell and fits in a 625 holder.

Prices around €4 or so without shipping.

 

[Anon Ymous]

I did a quick search on "px625 adapter" on Aliexpress and got many hits showing what looks like a machined brass insert that takes an LR/SR44 cell and fits in a 625 holder.

Prices around €4 or so without shipping.

That's for the 675 zinc air batteries, which will work just as well in an OM1 as the mercury batteries, with the only downside being the short (as in few months) life.

 

[koraks]

The ones I see will accommodate an LR/SR44, but evidently won't provide any voltage adjustment to the original 1.35 Cd chemistry. This can be done within the camera itself if required/desired. Perhaps we're talking about the same thing, but emphasizing different aspects of it

 

[Anon Ymous]

The ones I see will accommodate an LR/SR44, but evidently won't provide any voltage adjustment to the original 1.35 Cd chemistry. This can be done within the camera itself if required/desired. Perhaps we're talking about the same thing, but emphasizing different aspects of it

Well yes, we do, because LR44 has the same size that the 675 has. These are hearing aid batteries and can be bought very cheaply. Their short life isn't much of a concern really and their voltage is correct.

 

[koraks]

Well yes, we do, because LR44 has the same size that the 675 has.

Indeed

Their short life isn't much of a concern really

Well, that's a bit personal. I've always found it a nuisance, but that's as much due to my own limitations as the technology's.

 

[ic-racer]

This is new since I posted 2011 about a tiny voltage regulator. The engineering to get these micro voltage regulators on a little pc board had been done and the fully soldered assemblies are easy to obtain on the internet:

 

[MattKing]

I've used both type of adapters, and their suitability depends as much on my typical use of the camera or meter they are used in as it does of the characteristics of the batteries.
If I use a camera or meter regularly, and outside a studio, I prefer an adapter that works with the more expensive and slightly harder to purchase long lived batteries.
If I use a camera or meter episodically, or almost always close to home, the adapters that work with the cheaper and much easier to purchase shorter lived (hearing aid) batteries work great.
For clarity, if a camera requires the voltage that the mercury cells offered, an adapter that works with the hearing aid batteries will supply that voltage, but if you use a silver oxide cell in that adapter, the voltage will be wrong - one needs instead an adapter that converts the voltage to the target amount.

 

[Jimskelton]

I am looking for someone who has adjusted the meter to use silver oxide cells who is willing to share the procedure.

I would like to understand metering circuits better to understand how they could be modified to use a different voltage. Hopefully inquisitive minds will not be discouraged by the rhetoric in this thread to pursue alternate solutions to this problem.