Simple SM Resistor Question, and Fuse Question

[Jeff Walther]

I am trying to identify some surface mount resistors, without desoldering
them and measuring them. The markings on them are 75R0. I am guessing
this is 75 ohms. Is this correct? I am used to the ones with three
digits where the third digit is the tens exponent. I've never seen one
with an R inserted into the number before.

Second, any idea what a P 075 on a SM fuse means? The P is the top line
and it might be a rho. the 075 is on the second line. Or an LF 075 with
the F sitting inside the L and the numbers and letters all on one line.
The fuse is about a size C or D if this were a SM capacitor.

I guess while I'm here. I'm also looking at some tiny SM ceramic
capacitors. Looks like a size 0603 but there are no markings on them of
course. Do I just have to pull those off and measure them to get a
value? These are near the VGA connector of a video card. I don't have a
capacitance meter, although I do have a digital multimeter that measures
V, I and R. Is there any way to measure those without springing for a
capacitance meter? I seem to remember something about using the RC time
delay. Or recommendations on an affordable capacitance meter?

Thank you for any helpful or humorous comments.

--
A friend will help you move. A real friend will help you move a body.

 

[Michael A. Terrell]

Jeff Walther wrote:

I am trying to identify some surface mount resistors, without desoldering
them and measuring them. The markings on them are 75R0.
75.0 Ohms, 1%
^^^^^^^^^^^^^

^^^^^^^^^^^^^

I am guessing
this is 75 ohms. Is this correct? I am used to the ones with three
digits where the third digit is the tens exponent. I've never seen one
with an R inserted into the number before.

Second, any idea what a P 075 on a SM fuse means? The P is the top line
and it might be a rho. the 075 is on the second line. Or an LF 075 with
the F sitting inside the L and the numbers and letters all on one line.
The fuse is about a size C or D if this were a SM capacitor.

I guess while I'm here. I'm also looking at some tiny SM ceramic
capacitors. Looks like a size 0603 but there are no markings on them of
course. Do I just have to pull those off and measure them to get a
value?

Some have an almost invisible two character marking that can be read
under high magnification. On the other hand, if the manufacturer was a
cheapskate, they but the cheaper, unmarked version.

These are near the VGA connector of a video card. I don't have a
capacitance meter, although I do have a digital multimeter that measures
V, I and R. Is there any way to measure those without springing for a
capacitance meter? I seem to remember something about using the RC time
delay. Or recommendations on an affordable capacitance meter?

There are quite a few capacitor meters, from simple add on kits
(Ramsey, Rainbow, etc.), to kits like the AADE unit (also available pre
built)

Thank you for any helpful or humorous comments.

--
A friend will help you move. A real friend will help you move a body.

--
We now return you to our normally scheduled programming.

Take a look at this little cutie! ;-)
http://home.earthlink.net/~mike.terrell/photos.html

Michael A. Terrell
Central Florida

 

[Peter Bennett]

On Sat, 10 Jan 2004 02:24:01 -0600, trag@io.com (Jeff Walther) wrote:

Second, any idea what a P 075 on a SM fuse means? The P is the top line
and it might be a rho. the 075 is on the second line. Or an LF 075 with
the F sitting inside the L and the numbers and letters all on one line.
The fuse is about a size C or D if this were a SM capacitor.

I'd guess 75 mA

LF would be Littlefuse - a well-known maker of fuses. Have a look
around their website at http://www.littlefuse.com



--
Peter Bennett, VE7CEI
new newsgroup users info : http://vancouver-webpages.com/nnq
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[Jeff Walther]

Thank you, Michael and Peter.


I hope that folks will be as kind for one more question. I am looking at
another component that looks like a SM transistor in an SOT-23 package,
however the silk screening on the board says "REGn" where 'n' is an
integer. There are six pads, three to a side, but the components in place
appear to only have three pins as for an SOT-23 package. In other words
three pads are unused, three pads are used. The components is marked
K043. Any idea what this is?

Thank you.

--
A friend will help you move. A real friend will help you move a body.