Michael A. Terrell wrote:
Wes wrote:
Tim Wescott wrote:

_And_ it starts with a ni-starter -- Cox glow heads _demand_ a good dry
cell battery, and just sneer at you if you try to give them 1.2V from a
nicad.
http://www.metalworking.com/dropbox/cox_head.txt
http://www.metalworking.com/dropbox/cox_head-inside.jpg
http://www.metalworking.com/dropbox/...d-on_plane.jpg
http://www.metalworking.com/dropbox/cox_head-plans.jpg
http://www.metalworking.com/dropbox/cox_head-top.jpg

That .3v per cell matters at times.


A fresh carbon zinc is closer to 1.55 volts. 1.2 volts would be a
little over a 40% reduction in power dissipate in the glow plug.

It goes lower than that when you load it up with a glow plug. The power
reduction wouldn't be quite 40%, as the resistance goes down with
temperature -- but it's still enough of a drop that the engine gets to
be quite a bit harder to start.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com