Picaxe manual wiring diagram

Michael 2727

Senior Member
Short for 4K700.
4K would be 4,000 Ohms, the 7 after the "K" indicates the hundreds = 700.

2M2 is 2 Meg, 200,000 = 2,200,000 Ohms.
 

kevrus

New Member
I believe that the reason for putting the 'k' between digits instead of the decimal point is to reduce errors as a decimal point is easy to mis-print or dissapear in subsequent copies/documents.
There is also two main types of colour coding for resistors, 4 band and 5 band.
4k7 in 4 band would be yellow,violet, red, with the fourth band indicating tolerance...i.e. gold is 5%, red is 2% and brown is 1%
4k7 in 5 band would be yellow, violet, brown, black, with the fifth bieng the tolerance.
47k on the other hand is yellow, violet, orange plus tolerance (4 band) or
yellow, violet, black, red plus tolerance (5 band).
 

Dippy

Moderator
Nice one 4Kev7. Learning colour code is hugely handy as is learning the system used on SMD. Some resistors are poorly printed and can be a little ambiguous, so get a cheap multimeter too.

It really would be a good idea for the newer students to study up on 'conventions' used in electronic terms, whether schematic or component printing.

Getting values so wrong as in Chris's case could prevent a device working - resulting in days of posting here. Or it could result in the magic smoke release - resulting in an early bath.

Similar convention with "R" too. 4R7 is 4.7 Ohms. 10R0 is 10.0 ohms. 2M2 is 2.2 million ohms (aka megohms).

Also check out capacitors 4n7 is 4.7 nanofarads. 2u2 is 2.2 microfarads. (Sorry I couldn't do a mu).

Some components have letter marking too, which may require (strike me down Oh Lord!) reading a Data Sheet. I'm so sorry, please forgive me for saying that word. :)

So, Chris, I would suggest reading up on these standards and conventions so then we're all talking the same language.
 

manuka

Senior Member
Mnemonic!

Did someone mention colour codes? You can't beat a mnemonic for recalling these. I've had endless educational mileage with "Better Be Right Or Your Great Big Plan Goes Wrong" ( = 0 1 2 3 4 5 6 7 8 9 ), even though most Kiwi sparkies prefer a less politically correct version! Campus photocopiers & the like even abuse the system to show login codes in a Brown/Black/Red/Yellow (=1024) style - predictably only Electrotech users twig this. I wouldn't be surprised if folks recall bank card PINs or mobile phone numbers this way. Stan- in country code Blue Yellow
 
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hippy

Senior Member
You can't beat a mnemonic for recalling these. I've had endless educational mileage with "Better Be Right Or Your Great Big Plan Goes Wrong" ( = 0 1 2 3 4 5 6 7 8 9 ), even though most Kiwi sparkies prefer a less politically correct version!
Agreed. Mnemonics, particularly offensive and non-politically correct really do stick in one's mind.

See : http://en.wikipedia.org/wiki/Electronic_color_code

The variant I know ends, "Our Young Girls But Virgins Grow Wiser". Using "Black", arguably eminently sensibly, as the first word of the mnemonic is what can introduce a racist element as that article notes, and the version I know compounds that even further. Use with caution and remember; what one knows doesn't always have to be said.

Now whether it's "purple" or "violet" is a matter we could probably start a war over. I believe it depends upon which mnemonic sticks in memory.
 

Dippy

Moderator
Absolutement again.

Rude mnemonics usually stick, but shouldn't be encouraged.
I was brought up on 'Virgins' = Violet and the one I remember ended slightly differently to hippy's version.
But I don't want to start a potentially rude/offensive Mnemonics Competion.(Which would be deleted so please don't do it).
P for Purple would just be too easy. Maybe a tattoo would be the answer.

Bottom Line: Learn/remember what you can and jot down the rest in your grimoire.
And if it says 4K7 it means 4K7 and not 47K.
 

hippy

Senior Member
I'm intrigued : Which countries use 4.7K as opposed to 4K7 ?

I know Australia ( Silicon Chip ) uses the decimal point, while most of Europe seems to favour K where the point would be.

I've also seen America use 0.1uF where I'd use 100nF. That always makes me double-take because I expect 1uF upwards to be electrolytic, anything less to be non-electrolytic.
 

BeanieBots

Moderator
Capacitors seem to be a bit erratic in that respect. Certainly, the US would appear to prefer 0.1uF to 100nF and having worked for the US for 15+ years sometimes find myself doing it that way. The ones I don't get are the likes of 10,000pF.
The different cap types tend to use different conventions. Poly often in pF and disc use numbers or colours similar to the resistor code (eg 103=10nF). Very confusing for the novice:confused:
 

andrewpro

New Member
Whelp...I'm American...with an American electronics education, American engineering experience...and I'll tell ya...I don't like the "American way".

As far as the XkX thing, I prefer that. I actually got everyone in school including the instructors doing it too when I was in college. I guess it's jsut convention that the decimal is used, but I like to go through schematics and aprts lists fast...usualyl jsut scanning to get an idea of what's going on, and the decimal is much harder to pick up than the letter. Hand writing the decimal can get lost real easy with all the other pencil splatter, etc etc etc.


So far as the capacitor thingy....for some reason we Americans like to measure everything in microfarads. but there are exceptions...things like RF circuits I often see all values in pico. I too prefer using 100nF rather than 0.1uF. But for some reason we just seem to love microfarads over here. It bakes my noodle sometimes.

I like the "euro" way. It just makes more sense and is much more efficient.

--Andy P
 

Michael 2727

Senior Member
I was taught @ 14 yrs of age-
Black - Berries - Run - Over - Your - Garden - Blue - Violets - Grow - Wild. (G Rated)

But whatever works for you is the correct way ;)
 

MPep

Senior Member
Further to this interesting topic, in SMD/SMT resistor codes are usually written as 102. 10 + 2 zeroes behind it= 1000R or 1k => 1k0.
470=47R etc.
 
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