Hello,
9V block alkaline batteries i found not so much suitable like
a source for MD because of high internal resistance (GP 9V@
70-80 0f capacity about 3.7 Ohms!!, resulted in max. speed 3.5-4 fps),
NiCd and Nimh 9V (more likely 8.4V) would be better, NiMh has
higher capacity(200 mAh) than NiCd (120 mAh), BUT Nicd use to have
markedly lower Rint. than NiMh (cca two times),
which is very important for maximal power of DC motors.
As the best small batteries i found 1/3AA Nicd (format used in CP1/2) from
Sanyo
N-110AA with Rint ave. = 30mOhm per cell.
For reference good AA penlite battery NiMh has 23 mOhms and NiCd 12 mOms.
Recently i used 15 Sanyo cells(3 more than in CP2) with MD2 and reached
5.3 fps with film loaded @1/500s without MLU and 5.7 fps without film.
So hardest batteries from all are Nicd and paradoxly battery with
lower capacity and the same size can have lower Rint so can provide
higher peak current.
Hope it will be usefull for somebody who wants to rebuild CP1/2.
BTW: Last weekend i got 2-13 screen and i was so surpriced how bright
it is so i didn't mind about minor scratches and grabed it for about 25$.
Radek
----- Original Message -----
From: Markus Haukeboe
To: olympus@xxxxxxxxxxxxxxx
Sent: Tuesday, October 07, 2003 4:36 PM
Subject: RE: [OM]
Hi
I'm using a MD 2 with a recently rebuilt CP2. The new cells are bought from
Camtech, and I've only recharged them twice (Almost brand new).
I was actually playing with this combination yesterday. Using OM-1 with
mirror lockup and 1/1000 sec I reached 5,7 FPS. Letting the mirror travel I
reached 4,7FPS. I've also tried this on my MV18, but I hadn't completely fresh
batteries, so the result may not apply correctly. On my OM-3 on 1/1000 I
managed to make it fire at 4,6 FPS.
All tests where performed without film in the body. The rate is calculated
based on a digital wristwatch using a 10 second measuring frame. This off
course give plenty of variation, but I did the test several times inn all
cases, finding approximately the same values each time.
I've also got a MD1, and inspired by writing this I'm heading home to test
the same things with this.
Markus
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