newbie question about 100u or 100uf?

[lucas abela]

i'm new to this and am about to order parts for my first few projects and have noticed some list parts as 100u and others 100uf

i'm assuming these are the same thing as is say 10n and 10nf

also while im here does 3n3 mean 33n or 3.3n

some other things i've come across so far that i don't understand are

470p
LDR
10p

sorry for the stupid questions just want to make sure i get my first order right

[Chris60601]

LDR = light dependent resistor
p or pF = pico ferrad

AND ...
mF and uF essentially have the same meaning (well, in certain circles at least).
https://www.westfloridacomponents.com/blog/is-mf-mfd-the-same-as-uf/
http://www.diystompboxes.com/smfforum/index.php?topic=68678.0


Some other bits to help guide you....

1-999 pF - Generally we get Ceramic Caps. Sometimes you can find film caps in this range, but you're good with small ceramic caps. Get pin spacing of either 2.54 or 5mm.

1nF-1uF - Film caps. We like to use box film caps. You can also get Chiclet style caps, but film caps are pretty common and easy to find. You should be looking for pin spacing of 5mm, and voltages of 25-100V.

1uF-220uF - You will be looking at Aluminum Electrolytic capacitors, radial, of a diameter of 5mm where possible, and 6.3mm for 100uF and higher.

Use low profile electro caps (Small Bear has them) to help keep the layout as close to the board as possible. I like them cuz they look sexy

pF - ceramic caps
nF - box/film caps
uF - electrolytic caps.

[Beaker]

"Modern" resistor convention is as follows:

10R means 10 Ohms
1k5 means 1.5K Ohms (or 1500 Ohms)
1M5 means 1.5M Ohms (1.5 Mega ohms)

The same convention applies to capacitors, e.g. 2n2 means 2.2nF, 470p is 470pF etc.

 The reason is to eliminate the use of the decimal point (.) which can be missed when drawings are reproduced.

As with many things, this convention is not observed universally, so you may see different "versions" of the same values.

[induction]

Also, some manufacturers use mF interchangeably with uF (eg 10m = 10u), because apparently they hate the metric system.

[Chris60601]

Yup - I just edited my post to reflect that, then I saw your post.

[motterpaul]

I use this free software to find resistor and capacitor codes. http://www.electronics2000.co.uk/

It really does help to buy with an eye for size in the first place - especially with caps. There are many different types.  A lot of circuits here use 1uF inline caps (no polarity) and you can buy them. In many cases you can use electrolytics in their place, but you have to figure out how to orient the polarity.

With 100uF and higher electrolytics I generally try to buy 25v with small diameters, because higher voltages can be too big to get on your board. I bought a batch of 100 uf without noticing the size, because the picture made them look small, but when they arrived they were massive.

[Muadzin]

induction wrote

Also, some manufacturers use mF interchangeably with uF (eg 10m = 10u), because apparently they hate the metric system.

*cough* Small Bear *cough*

The fun that wasn't that I used to have with ordering from them the first times around.

[lucas abela]

on smallbear now and jeez it's confusing

all the caps are listed as mf microfarads which on our vero board layouts are listed as pF / nF or uF

as i understand from above mf and uf are the same so i need to convert all these decimals from uf to pf or nf

so considering i was considering just getting their starter packs like

http://smallbear-electronics.mybigcommerce.com/capacitor-low-voltage-50-volt-poly-film-assortment/

which lists the parts as

.001 mf, .0047 mf, .01 mf, .047 mf, .1 mf, .0022 mf, .0033 mf, .0068 mf, .022 mf, .068 mf

if i convert correctly i shift the decimal point three spaces to the right to get nf right? meaning the above is this?

1nf, 4.7nf, 10nf, 47nf, 100nf, 2.2nf, 3.3nf, 6.8nf, 22nf, 68nf

and then another 3 points for pf?

1nf = 1000pf

i think im right just checking as the use of m not u is freaking me out

[induction]

You got it.

[rocket88]

microfarads are uF

[Beaker]

Lucas, you are correct, and it is confusing until you get your head around it.

I suggest you use a chart like this:

http://3.bp.blogspot.com/-qx4nyT_9NoM/VISIMj0LuoI/AAAAAAAAAyM/fjrHehm9g5c/s1600/Capacitor_Letter_Codes_Table.png

Print it out, laminate it if you can, and stick it to the wall behind your work bench. It will save you loads of head scratching!

Using this chart, you can also work backwards - find the caps value from the code number printed on it, which is a very useful feature.

I hope this helps.