OK – final follow-up.
Fuses (1.25A) arrived. Popped the old one out, new one in.
Battery into camera, then out: Fuse good
Camera on: Fuse good
Load film: Fuse good
It must have just been coincidence that the fuse died at the same time I did
the cell change. I guess that strange things do happen…
j
---
Jeffrey L. Bromberger
jeffrey@xxxxxxxx
From: rollei_list-bounce@xxxxxxxxxxxxx
[mailto:rollei_list-bounce@xxxxxxxxxxxxx] On Behalf Of Laurence Cuffe
Sent: Saturday, February 10, 2018 5:07 PM
To: rollei_list@xxxxxxxxxxxxx
Subject: [rollei_list] Re: Upgrading the 6008 fuse?
I would second the notion that uprating the fuse, might be a mistake.The
originals were, I think NiCad’s. The internal resistance of these Cells is abut
half that of NiMH cells. This means that they are the cell of choice of high
current, intermittent use applications. For the 6000 series cameras, it seems
that this increase is not significant, although I am not sure about this for
the 6006, See this webpage which does not list the NiMH re-celling as
appropriate for the 6006.
https://rolleiflex.us/products/rebuild-service-for-rollei-6000-series-battery-pack-with-nimh
there is good information in general on battery chemistries on this
page:http://www.ka7oei.com/nicds.html
I would be concerned that what you thought was an ageing battery, might
actually be a camera which was failing in a way which drew more current. The
blown fuse supports this. It might be worth changing the lens, or even removing
the lens before replacing the battery and fuse. If you see a change in
behaviour as a result of this, it may localise the problem.
Putting in a larger fuse defeats the purpose of the fuse, which is to protect
the valuable device, by destroying a cheap part. You don’t want to protect a
cheap, though large capacity fuse by smoking the camera.
All of the above should be taken with a degree of caution. I acquired my first
6000 series camera, a 6006 Mod 2, 5 days ago and have been reading assiduously
on the internet to try and get it working since. I have two type G chargers and
three dead battery packs. Three lenses, and four backs. Also 3 SLX manuals,
and one 6006 manual.
best
Laurence Cuffe
On 10 Feb 2018, at 19:45, Richard Urmonas <richard@xxxxxxxxxxx
<mailto:richard@xxxxxxxxxxx> > wrote:
The lens uses "linear motors" to drive the shutter and aperture
mechanisms. The fuse protects the camera in case the linear motors
should draw excessive current (for example a jam)
In your case I would try a new fuse and see how it behaves. I have
seen old fuses fail after being disturbed, and that may have been the
cause of the fuse blowing.
Richard Urmonas
10 February 2018 08:05 "jeffrey tram.com <http://tram.com> " <jeffrey@xxxxxxxx
<mailto:jeffrey@xxxxxxxx> > wrote:
First off, I must have a typo in the original. I went with NiMH, not Lithium
cells. Either it was spell check, or my fingers went faster than my brain
could handle. You have my apologies for the confusion.
The cells went in without a hitch, and they charged with my Charger N. One
hour of charge time, then into slow mode. I figured that this would be enough
for the first test. I realize that you sometimes need 3 cycles to fully charge
them, but I should have enough on the cells for the point to get across.
I am awaiting the arrival of new fuses, so I can determine where they actually
pop. FWIW: I agree with your explanation, that it is the camera that draws
current from the cells. That's the way it was way back when I took Physics.
But I read somewhere (and searching is not bringing it back up) that you needed
to up-rate the fuse when going to the NiMH cells. Doesn't make sense to me,
but I was a Chem major, and Physics was just a requirement.
Let us say, for fun, that I put in a 10 amp fuse. If the camera is working
without a problem, it will never draw that amount, and the fuse will never pop.
And it's clear that the cell can't *push* excessive amperage of its own free
will. So except for a dead short, what exactly is that fuse there to protect
against?
j
