My Solution to RF (Yashica) batteries

P

pb908

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I have made simple schematic for you all, this is what I have use on almost all of my RF.

most RF use 1.35V, 2.7V, or 5.6V
my solution for all battery :



1. 1.35V battery, normally I put SR44/LR44 (with o-ring for 625 size) and connect a germanium diode (hard to find, need to test it first to find 0.2V voltage drop) inside the RF it self, so later on I just need to change the 1.5V battery

2. 2.7V battery, on my Lynx 14e, I use 6V battery (4 x 1.5V LR44), or can be higher battery, and modify the battery chamber to accept those higher batteries, open the bottom cover of my Lynx and find the red cable which is the power cable coming from the metering switch. I use LM317LZ and with just 2 resistor I manage toregulate the higher voltage to be 2.7V.
solusi2.jpg

as this circuit always takes 5mA current during ON condition, that's why I prefer to use it on any RF which have On/Off switch to enable metering (lynx 14E is perfect example). that will save the battery for long time
On my case, Lynx 14e, I need to get 2.7V so I use 290ohm resistor as per this calculation below :
solusi2resistor.jpg

you can modify the R value to for another voltage you need. few things to be note is that you need to have voltage at higher than the value you want to get, at least 1.5V higher if I am not wrong.

3. and the last solution for my Yashica GL (5.6V) :
solusi1.jpg

there are few option, but on mine, I use Cr/MN 21 or 23 (12Volt battery that is used on car key remote, alkaline) which is cheap and powerfull (more than coin type battery). and drop the voltage with zenner diode (5.6v) and one common silicon diode (I use 1n4007), and I get 5.7V at the end of the circuit. I installed all the diodes inside camera (I need to open the bottom cover) and solder the diodes on battery compartment), modify the battery compartment to accept the MN/CR 21/23 size (another spring and a foam) and my GL is up and running !!!

hopefully this help some people..

Regards
BK
 
Why not use two germanium diodes with the 4 x LR44 to get to 5.6V instead of 5.8V? Also, wouldn't SR44 batteries be better than LR44 as I think the output is more constant (isn't it?).
 
possible..

possible..

monopix said:
Why not use two germanium diodes with the 4 x LR44 to get to 5.6V instead of 5.8V? Also, wouldn't SR44 batteries be better than LR44 as I think the output is more constant (isn't it?).
Click to expand...

it is possible, in my country it is hard to get SR44 and germanium, that's why I prefer the other option.

I was surprised to see that my GL draw current up to 90-100mA during exposure, it will be hard for LR/SR44 type battery for sure. they are not design to accept that much of power draw. I have not test it, but I am sure the battery drop will be significant during exposure. just my thought. I prefer to use the MN/CR 21/23 solution
 
Simplify!
A single 6v works great with spring to take up slack.
Careful guys. You will confuse folks who should otherwise be making phots ;)
 
gk's battery 'solution'

gk's battery 'solution'

hey mr GK - not so sure about your so-called battery replacement 'solution'. besides not being written and diagramed clearly it's too complicated, too much work, and most of us are not electrical engineers. easiest solution is about $7 for an exell battery that is a direct replacement.
louis
 
are you finding the germanium diodes to have consistent drops over various temps?

Not sure of the Lynx and other rf's mentioned, but the common electro seems to be regulated (I tested '70s era ones), no exposure change with voltage or current changes +/- 25%.
 
lou707 said:
besides not being written and diagramed clearly it's too complicated,
Click to expand...

It's clear to me and not complicated at all. Just because you don't understand it, don't knock it.

most of us are not electrical engineers.
Click to expand...

...which is why you don't understand it.

easiest solution is about $7 for an exell battery that is a direct replacement.
Click to expand...

Now that IS being unclear. Which battery are you talking about? How about a part number? There are no 'direct' replacements for the original murcuric oxide battery but there are batteries that work - and many that don't.
 
pb908 said:
I was surprised to see that my GL draw current up to 90-100mA during exposure, it will be hard for LR/SR44 type battery for sure.
Click to expand...

I have made 625 adapters with shottky diodes and SR44 cells - I was amazed to find that they will pass >200mA with no problem. OK the battery life is shorter, but still measured in months.

I accidentally shorted one, and it drew 2A before it blew!
 
john neal said:
SR44 cells - I was amazed to find that they will pass >200mA with no problem.
Click to expand...

But what was the volt drop through the battery?...

It's not just what current they can deliver but what the internal resistance is and hence, what voltage they will output at such high currents. The SR44 will work OK with Electro 35s as will the LR44, though the volt drop of the LR44 may prevent the battery check light from operating. But it's the wide voltage tolerance of the circuit that makes it work, not that the battery is anything like doing what you really want it to.
 
john neal said:
I have made 625 adapters with shottky diodes and SR44 cells - I was amazed to find that they will pass >200mA with no problem. OK the battery life is shorter, but still measured in months.

I accidentally shorted one, and it drew 2A before it blew!
Click to expand...

John

If you make any more adaptors, let me know. They work very well.
 
monopix said:
But what was the volt drop through the battery?...

It's not just what current they can deliver but what the internal resistance is and hence, what voltage they will output at such high currents. The SR44 will work OK with Electro 35s as will the LR44, though the volt drop of the LR44 may prevent the battery check light from operating. But it's the wide voltage tolerance of the circuit that makes it work, not that the battery is anything like doing what you really want it to.
Click to expand...

Fair point - power is, after all, a fuction of both current & voltage. From memory, it was still putting out 1.34v at 200mA, so fine for most cameras that require one P625, and high-drain applications like the Nikon F or some lightmeters. I have never tried it with any of the 5.6v cameras - I would prefer to build a Wheatstone Bridge into the body. I did make one for Kim Coxon that replaced the P640 (I think) and that was fine too.

Unfortunately, I now have to use silver based solder, thanks to the EU rules on lead, and find that the higher melting point fries too many diodes :(
 
very well replied..

very well replied..

monopix said:
It's clear to me and not complicated at all. Just because you don't understand it, don't knock it.



...which is why you don't understand it.



Now that IS being unclear. Which battery are you talking about? How about a part number? There are no 'direct' replacements for the original murcuric oxide battery but there are batteries that work - and many that don't.
Click to expand...

no more to add.. thanks monopix!

I believe all of you can find whatever solution suits to whatever battery on your local supplier. as mine, two simple diode and one zenner do the job (just stop by any electronic store if any, ask for it). may be radioshack in US supplied them as well.
 
john neal said:
Fair point - power is, after all, a fuction of both current & voltage. From memory, it was still putting out 1.34v at 200mA, so fine for most cameras that require one P625, and high-drain applications like the Nikon F or some lightmeters. I have never tried it with any of the 5.6v cameras - I would prefer to build a Wheatstone Bridge into the body. I did make one for Kim Coxon that replaced the P640 (I think) and that was fine too.

Unfortunately, I now have to use silver based solder, thanks to the EU rules on lead, and find that the higher melting point fries too many diodes :(
Click to expand...

how long a series of 4 SR44 will last in your yashicas ? just want to know..;)
 
Probably people with knowledge in electricity can comment difference between 4SR44 cell and stack of 4 SR44's. I've got 4SR44 cell made by Camelion, states 6.2V and costs two times less than 4 Varta made SR44's. Will see if price directly reflects qualities.
Good thing is that 4SR44 directly fits (and is prescribed) Electro 35 MC.
 
I use a Yashica Electro 35 GSN with a Duracell PX28ABPL with a spring to fill the gap and a little piece of cardboard around the battery. It works just fine.
 
I do not know, I put 4x alkaline batteries in a Electro 35 (taped together with an extra spring to make them fit)
Pictures turned out fine, even within 1/2 stop..... so maybe they have a bridge circuit and small voltage variations do not affect the camera too much?

PS: Maybe I'm not so crazy... look here:
http://www.mattdentonphoto.com/cameras/yashica_gsn.html
 
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