by Steve Anderson » Tue Apr 16, 2013 11:22 pm
Now one would think that resistor colour codes would be quite simple, alas, not so...I'm only using this as a base example....
On yer general 1/4W resistoid the bands are 1mm or less wide, the background body colour can bleed through too, usually a blue-ish grey on 1% parts or a cream/beige on 5% versions. Although OK on primaries and their compliments I am slightly colour blind to pastels, someone will tell me those shoes are a brown or tan, whereas to me they are grey...or vice-versa.
What doesn't help is when (often) the tolerance band isn't spaced apart from the actual value, e.g. with 1% parts Brown, Red, Brown, Brown, Brown. (1k2, 1%) or Brown, Brown, Brown, Red, Brown. (11k, 1%). A very common value with potential for confusion is 10k.
Even though fairly confident with being able to read resistor values I do still sometimes check them, even though my stocks are bagged in storage by value, there have been instances where the local supplier has made errors and I haven't picked them up.
The multimeter is of course the ultimate check, but it is a pain having to use it when it shouldn't be required.
We can be grateful I guess that those capacitors which looked like Liquorish Allsorts and other colour-coding systems seem to have fallen out of favour...a printed 102 (1000pF, 1nF) in black text is far preferable...even if I do need a magnifying glass to see it!
Steve A.