2.7v voltage regulator for meters, cameras, etc.

[Xmas]

http://olympus.dementix.org/Hardware/

Frans & Tim provide descriptions of diode solutions on this site.

But before you dive into gory detail

Some cameras have variable resistors to allow easy replacement of CdS cells as they can age. If they are fixed resistors it is more difficult but in either case you can set them up for silver cells as easy as mercury.

It takes real skill to not cook the small diodes

The hearing aid batteries are cheap cept they won't work for low current draws eg Lunasix!

Simplistically a diode only conducts current in one direction. But when it is conducting current it reduces the voltage as well. If you pick the correct diode you can make a silver cell look like a mercury cell.

If you have two batteries in your camera you need two diodes, etc.

If you convert a camera please stick an Avery label in cassette chamber.

 

[AgX]

Now, what are disadvantages of a regulator:


-) size (though smaller by now)

-) own power consumption (though smaller by now)

-) the need to be switched off to not drain the battery when camera is not in use (thus less freedom in positioning)


Anything else?

 

[F4user]

Found one with excellent performance
exar sp6200em5-2.7
ground curent 28-100 uA
Dead Link Removed

 

[Xmas]

Now, what are disadvantages of a regulator:


-) size (though smaller by now)

-) own power consumption (though smaller by now)

-) the need to be switched off to not drain the battery when camera is not in use (thus less freedom in positioning)


Anything else?

You need a whole solution eg

a battery
new CdS cells maybe

etc.

If you need new CdS cells you need new resistors so you can set up for silver, no other changes no regulator.
If you don't have an off switch like a OM1 you would need an off switch like a K1000s ie an additional CdS cell and transistor switch not impossible, but SMD probably
necessary, just getting a diode into an OM1 is not easy.

The rule in design is KISS, the contax I, II and IIa were bad designs. A silver cell is a regulator.

Build a diode into a old battery case, simple to move around several cameras.

I don't use a battery at all most of the time. I find moving needles or lights too compelling

 

[AgX]

I do not understand:

A battery is needed in any case. The fredom in choice of that is the topic of this thread.
Why would I need a new CDS-cell when regulating the power supply?

 

[Xmas]

Sorry the starting point is you buy or inherit a camera and want to use it.

So if you try it with hearing aid cells in case it is broken or has been adapted already and it does not work too well you need new cells or wiring.

Or it works ok so you only need an adapter.

If you need new cells you can set up the resistors for silver batteries.

If you need to rewire start from top again.

Most cameras come with no provenance even if they are ex grand fathers.

Most work perfect I've even had one that had been adapted already.

The resistors are not impossible if you can get the camera to work partly rebuilt tack in a replacement variable resistor set up low level resistor replace with fixed do high level same way. You need to make or find a schematic diagram first.

You need recall of all electronics school courses or a book.

Or send it off for service...

 

[John Koehrer]

The SMD regulator seems to be smaller than the diode so placement isn't a problem.

A great many of the solutions are useful ONLY if you're familiar with the circuitry, able to read, interpret and/or troubleshooting techniques.
Not everyone is an engineer believe it or not.

 

[Xmas]

The SMD regulator seems to be smaller than the diode so placement isn't a problem.

A great many of the solutions are useful ONLY if you're familiar with the circuitry, able to read, interpret and/or troubleshooting techniques.
Not everyone is an engineer believe it or not.

Yes I did say you needed to recall your electronics, and most of my school class were arts.
The diodes I have are as small as any SMD and have leads but are still difficult, see the OM1 fit details, in link
If you don't feel confident the adapter solution is available for $, and works on most equipments. If the camera needs new photo cells repair shop.
SMDs glass boards & hot air guns not much fun either.

For my own OM1s I use a rubber ring and hearing aid button or sunny side /16. They are so reliable never need the base plate off.