Re: A Weight Reduction Plan....
- From: David Young <telyt@xxxxxxxxx>
- To: leica@xxxxxxxxxxxxx
- Date: Sun, 11 Mar 2007 13:02:23 -0700
At 11/03/2007, you wrote:
David:
Very nice repackaging job on a bulky item. You could go into
business selling these with a slightly cleaner version, like Tom
Abrahamsson and his Rapidwinders. Just have interested customers
send you their original chargers, and send back a shrunk one - for a
fee, of course!
Your shot of the innards shows a PC board with somewhat archaic
through-hole construction. Leica probably doesn't have enough demand
for a surface-mount board with a switching power supply.
Was there any special bonding of the metal heat sink fin to the
original case? If there was, you run a minor risk of overheating the
load transistor in your new case. Also, there may be a thermal
airflow problem with your cooling holes on your new case. If its top
feels warm to the touch in use, you might consider drilling some
holes there to enhance heat flow out.
Just a few thoughts from a former engineer... ;)
Mark
Hi Mark!
The metal heat sink was not disturbed, so any thermal compound
between the regulator and the heat sink is still intact. Heat,
seems not to be a problem, even with the "new" charger plugged in for
some 48 hours (as a test). It stays cool to the touch. So far, so good!
When our new son-in-law comes back from Costa Rica, next week, I'll
borrow his laser temperature probe and measure the case temps of
both, after having them both plugged in for 48 hours. I'll report back.
As for the "archaic, through hole construction", you are right... but
Leica don't build these units.. Ansmann (
http://www.ansmann.de/cms/isroot/chargers.html ) do, and Leica simply
buy an "off the shelf" charger from them. It's a nicely built
unit, but way too big for a camera case.
My modified charger is still too big, but a heck of a lot
smaller! If I understood more about electronics, I'd try to build a
smaller one, from scratch. But, my electronic theory is weak, and my
knowledge of charging LI-Ion batteries is non-existent!
As for charging to modify other peoples chargers... the hours needed
would cost more than a new charger! It's a great idea,
but.... Besides, for those who wish to know more, an article on
this project has been accepted for publication in the next issue of
the LHSA's Viewfinder.
BTW: I really liked your article in the current issue, about
measuring focal lengths using the stars. Slick!
Cheers!
---
David Young,
Logan Lake, CANADA
Wildlife Photographs: http://www.telyt.com/
Personal Web-pages: http://www3.telus.net/~telyt
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