OT: fuses - test-drb@ccmp.vtda.org

28 Dec 2003

On Dec 28, 23:07, Chad Fernandez wrote:
...
  Tony,

 the fuse itself has an "F" inside a "L" looking line.  One circular
end
...
  has a symbol that I can't type and the other has a
"237" "UL" and an "SA".

IIRC, that F-in-an-L is the logo for Littelfuse.  It certainly doesn't
mean fast-blow.  You probably want a slow-blow fuse for a device like
this.  Why?  Because in many electronic devices, there's a surge of
current for a short while, when you first switch it on.  This is caused
by the capacitors charging up, and is quite normal.

...
  I find one cylindrical cap that is 200v and 220uf and
one 250v .1uf cap
...
  that looks like a chicklet (kind of chewing gum).  I
don't have any idea
...
  how to identify a chopper transistor..... could that
possibly be labeled
...
  "Q1" and have a heat sink on it?  I also see
a couple transformers and a
...
  bunch of resistors an IC and assume most of the
D#'s are diodes.  There
...
  are quire a few "Q#" labeled items too.

Yes, "Q1" is a designation for a transistor, normally.  And the voltage
ratings for the capacitors suggest they're close to the mains, which
implies a sitching PSU, not a linear one. The small chicklet cap is
probably an X-rated or Y-rated suppressor cap.  The transformers are
probably fairly small (an inch or two on a side), yes?  For a linear
supply, I'd expect one big transformer, probably mounted on something
solid; one or more small(ish) ones are typical of a switcher.  Anyway,
unless this laservision player is unusual, I'd expect such a device to
have a switcher.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York