Olympus OM-2n and power consumption

[E. von Hoegh]

Maybe the answer is to think less along the lines of an electrical switch and more along the lines of a mechanical solution that makes or breaks the +ve connection with the inside of the battery cover. This would require a mod to the existing battery cover to incorporate the cutoff mechanism accessible from underneath the camera, though I've not got any bright ideas of exactly what that could be.

That's exactly what he is describing.

 

[E. von Hoegh]

The electrical switches that I've been talking about are that- they break the connection. The idea would be to have the switch close the circuit between the battery and the cover, rather than the battery being connected directly to the cover. You could use plastic with an electrode for the battery, connect to the switch, the switch connects to the battery cover. The slide switch, or rocker switch is used to make the connection, or turn it off. These switches are often used instead of Jumpers on computer boards. they are small.

I had a look at some of the tiny switches available, also eyeballed the dimensions of lithium cells. Using a lithium cell, it would be possible to cut open the middle of the coin slot, mounting the switch so it is moveable with something the dimensions of a toothpick and still be able to open the cover via the original coin slot.

A few years ago I designed an adapter for cameras and meters using two 625 mercury cells. It fit where the two cells did, used two lithium cells, and used a surface mount VR chip and a few discrete components to provide 2.7v until the lithiums got down to about 4v. Then I learned how to use 675 aircells and sort of forgot about it.