Fuse or fusible resistor?
in [Repair]
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From: Jamie on 27 Jun 2010 15:08 Tim Williams wrote: > "DaveC" <invalid(a)invalid.net> wrote in message news:0001HW.C84C25A9011554E5B01AD9AF(a)news.eternal-september.org... > >>Used in the battery (-) lead of a handheld scope. Schematics unpublished. >> >>Physically similar to a 1/4 W resistor, color light green. Marked "IE7A" or >>"1E7A". > > > Obviously, it's 10,000,000 amperes ;^) > > Tim > good one :)
From: James Sweet on 27 Jun 2010 17:14 > > I take it , that its blown and I also take it that its not charred (fusible > R don't char or even discolour AFAIK) > Desolder it and scrape an axial line along its length . Then DVM resistance > check from either end. If a fusible resistor then maximum R read is what its > value was near enough. > FR breaks are usually to one end, normal R usually in the middle. > Although green is often axial inductor. > > -- > They won't catch fire but I have seen them char slightly. It's also common for them to crack or blow out a small chip of ceramic if something shorts and exposes them directly to the line voltage.
From: fly on the wall on 27 Jun 2010 20:52
On Sun, 27 Jun 2010 00:27:45 -0700, DaveC <invalid(a)invalid.net> wrote: >> I take it , that its blown and I also take it that its not charred (fusible >> R don't char or even discolour AFAIK) > >No, I don't have one. I threw it out with the old battery. :-( >Someone on-line volunteered to describe the one from his scope. >I'll not ask him to do a post-mortem on a working fuse. ;-) Surely (s)he can MEASURE the one (s)he has? |