Hi all,
Sorry for being such a noob!
But, if you see a capacitor in a schematic labeled 0.1 or 0.01 etc
what is the unit of capacitance meant to be?
The unit of measurement is the Microfarad or uF. If you see a value of 100nF it is the same as a .1uF, a .01uF is a 10 nF capacitor, you will see both units of measurement A Nanofarad is 1000 picfarads ot Micromicrofarads. I hope this is of help for you.
Doc
That's great,
Thankyou very much!
So I can always assume a cap in a schematic with a value but no units is always referring to Microfarad's.
Plecc:
So I can always assume a cap in a schematic with a value but no units is always referring to Microfarad's.
"Always" is a harsh word to use. There is no "standard", only conventions.
Sometimes you might have to use some common sense (or ask someone with more experience).
Often ambiguous values will be labeled, but anything with a polarized symbol is usually going to be an electrolytic cap measured in microfarads. If it's a nonpolarized cap with a number around 1-100 it's probably measured in picofarads unless otherwise specified. If you see a three-digit number it most likely should be matched exactly to what's written on the cap; e.g. 104 (meaning 100000 picofarads, or 100 nanofarads, or 0.1 microfarad) should be matched to a (probably tantalum, film, or mica type) cap labeled 104.
xolroc:
Often ambiguous values will be labeled, but anything with a polarized symbol is usually going to be an electrolytic cap measured in microfarads. If it's a nonpolarized cap with a number around 1-100 it's probably measured in picofarads unless otherwise specified. If you see a three-digit number it most likely should be matched exactly to what's written on the cap; e.g. 104 (meaning 100000 picofarads, or 100 nanofarads, or 0.1 microfarad) should be matched to a (probably tantalum, film, or mica type) cap labeled 104.
My advice is to not follow anyone's bad example and always put the multiplier in when you annotate a circuit. I've never understood the seeming avoidance of nF and mF in favour of pF and uF amongst capacitor vendors. No-one avoids nV, mV, nA or mA, so this oddness with capacitors has no rational explanation.
When I retired (4 years ago) there was a general shift to the 'newer standard' I notice more and more use of the newer standard. Slowly but it is transitioning.
Doc