novice question

[Andy C]

hi all,
i'm building a small electronics project which was bought in kit form...
bear with me i'm a beginner
everything is soldered onto the board except for a few components i'm not
sure about...
there are places on the board left for 4x 1microF capacitors (the tiny ones
which aren't polarity sensitive- not sure the proper name!) i have 4x
capacitors with just the number "105" on them left over- do you think they
have sent the wrong capacitors or is "105" actually a 1microF capacitor?

there are also 9 places on the board left for 9x 100nF capacitors... i have
9x capacitors with the number "104" left over - are these the wrong ones?

many thanks!!
andy

 

[Puckdropper]

*snip*

there are also 9 places on the board left for 9x 100nF capacitors... i
have 9x capacitors with the number "104" left over - are these the
wrong ones?

many thanks!!
andy

Capacitors are labeled funny. (To me, at least.) What I usually do is
search for "104 capacitor" via Google, and often I get a page with the
value of the capacitor. If you're doing a lot of work with capacitors,
you'll want to learn the codes. If it's just a "now and then" thing,
there's no need.

Puckdropper

 

[Anthony Fremont]

hi all,
i'm building a small electronics project which was bought in kit
form... bear with me i'm a beginner
everything is soldered onto the board except for a few components i'm
not sure about...
there are places on the board left for 4x 1microF capacitors (the
tiny ones which aren't polarity sensitive- not sure the proper name!)
i have 4x capacitors with just the number "105" on them left over- do
you think they have sent the wrong capacitors or is "105" actually a
1microF capacitor?

Yes, the 105 means a 10 followed by 5 zeroes or 1,000,000pF (pico-Farads)
which is exactly equal to 1uF (micro-Farad), or even 1,000nF (nano-Farads)

there are also 9 places on the board left for 9x 100nF capacitors...
i have 9x capacitors with the number "104" left over - are these the
wrong ones?

Those are the correct caps. 104 is 10 followed by 4 zeroes or 100,000pF
which is the same has 100nF and .1uF. Does that help?

In descending order it goes Farads(F), mill-Farads(mF), micro-Farads(uF),
nano-Farads(nF), and pico-Farads(pF).

 

[Chris]

hi all,
i'm building a small electronics project which was bought in kit form...
bear with me i'm a beginner
everything is soldered onto the board except for a few components i'm not
sure about...
there are places on the board left for 4x 1microF capacitors (the tiny ones
which aren't polarity sensitive- not sure the proper name!) i have 4x
capacitors with just the number "105" on them left over- do you think they
have sent the wrong capacitors or is "105" actually a 1microF capacitor?

there are also 9 places on the board left for 9x 100nF capacitors... i have
9x capacitors with the number "104" left over - are these the wrong ones?

many thanks!!
andy

Hi, Andy. You're doing fine -- your caps marked 105 are 1uF, and the
104s are 0.1uF or 100nF caps. You can complete your kit with the
parts you have.

This is a common newbie question. For many good answers to your
question, go to Google Groups s.e.b. and search in that group for the
phrase capacitor codes (no quotes).

Congratulations on getting the parts right. That's not the easiest
thing for a newbie. Hope everything works OK. If not, feel free to
post again -- be sure to mention the kit manufacturer and kit number
-- it helps.

Cheers
Chris

 

[Andy C]

What I usually do is

search for "104 capacitor" via Google, and often I get a page with the
value of the capacitor.

thank you! don't know why i didn't think of that !!

 

[Peter Bennett]

hi all,
i'm building a small electronics project which was bought in kit form...
bear with me i'm a beginner
everything is soldered onto the board except for a few components i'm not
sure about...
there are places on the board left for 4x 1microF capacitors (the tiny ones
which aren't polarity sensitive- not sure the proper name!) i have 4x
capacitors with just the number "105" on them left over- do you think they
have sent the wrong capacitors or is "105" actually a 1microF capacitor?

there are also 9 places on the board left for 9x 100nF capacitors... i have
9x capacitors with the number "104" left over - are these the wrong ones?

many thanks!!
andy

Ceramic capacitors are often marked with their values in picofarads,
using a three digit code: two digits plus a multiplier.

Your "105" capacitor is 1, 0, 00000 pF, or 1,000,000 pF which equals 1
uF. the "104" parts are 0.1 uF or 100 nF or 100,000 pF.


--
Peter Bennett, VE7CEI Vancouver BC, Canada
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

[Peter Bennett]

In descending order it goes Farads(F), mill-Farads(mF), micro-Farads(uF),
nano-Farads(nF), and pico-Farads(pF).

Use of milli-Farads can be confusing and/or hazardous.

In ancient times, before the Greek alphabet was invented, we used "mF"
or "MF" to mean microfarad (and mmf for micro-micro farad, now called
picofarad), so using mF for millifarad will confuse many older techs,
and mislead newer techs looking at old schematics.



--
Peter Bennett, VE7CEI Vancouver BC, Canada
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

[Anthony Fremont]

Use of milli-Farads can be confusing and/or hazardous.

In ancient times, before the Greek alphabet was invented, we used "mF"
or "MF" to mean microfarad (and mmf for micro-micro farad, now called
picofarad), so using mF for millifarad will confuse many older techs,
and mislead newer techs looking at old schematics.

You're right, and I just saw a schematic using mF for uF, why oh why.

 

[Homer J Simpson]

there are places on the board left for 4x 1microF capacitors (the tiny
ones which aren't polarity sensitive- not sure the proper name!) i have 4x
capacitors with just the number "105" on them left over- do you think they
have sent the wrong capacitors or is "105" actually a 1microF capacitor?

there are also 9 places on the board left for 9x 100nF capacitors... i
have 9x capacitors with the number "104" left over - are these the wrong
ones?

http://www.uoguelph.ca/~antoon/gadgets/caps/caps.html

Have a look at Fig. 2 and Fig. 3. As you can see it all looks very simple.
If a capacitor is marked like this 105, it just means 10+5 zeros = 10 +
00000 = 1.000.000pF = 1000 nF = 1 µF. And that's exactly the way you write
it too. Value is in pF (PicoFarads). The letters added to the value is the
tolerance and in some cases a second letter is the temperature coefficient
mostly only used in military applications, so basically industrial stuff.

 

[Rich Grise]

hi all,
i'm building a small electronics project which was bought in kit form...
bear with me i'm a beginner
everything is soldered onto the board except for a few components i'm not
sure about...
there are places on the board left for 4x 1microF capacitors (the tiny
ones which aren't polarity sensitive- not sure the proper name!) i have 4x
capacitors with just the number "105" on them left over- do you think they
have sent the wrong capacitors or is "105" actually a 1microF capacitor?

there are also 9 places on the board left for 9x 100nF capacitors... i
have 9x capacitors with the number "104" left over - are these the wrong
ones?

Those are the right caps. The numbers are just the standard color code
printed in numbers instead of colors. So, for the 105, that's one '1',
one '0', and five more '0's, or 1,000,000 pf, which is 1 uF. Same with
the 104: 1 0 0000, which is 100 nf == 0.1 uF == 100,000 pf.

You might try googling on "color code" or "resistor color code".

Have Fun!
Rich