Electronics > Beginners

Purpose of 3rd band in resistor being black.

<< < (5/5)

Zero999:

--- Quote from: Stray Electron on July 27, 2019, 02:08:40 am ---
--- Quote from: R502 on July 26, 2019, 02:31:09 am ---Ok thank you guys for the replies. I understand it a little better now.

And that is not a very nice mnemonic.

--- End quote ---

  Then you would have HATED the original. Substitute the word "Black" for "Bad"

--- End quote ---
The one I learned also substituted boys for bastards.

Generally more politically incorrect and offensive things are easier to remember, probably because they invoke a strong emotional response, whether it be disgust, humour or a bit of both.


--- Quote from: Brumby on July 27, 2019, 02:18:16 am ---PS.  The choice of blue bodies for metal film resistors was, I think, the worst decision possible.  Makes picking the colours very difficult at times.

Whoever agreed to that needs to be shot.

--- End quote ---
I agree. I'm slightly red-green colour blind. I have deuteranomaly. This doesn't mean I can't tell the difference between red and green at all. I have both red and green cones on my retina. It's just the green cones have a slightly lower peak frequency response, than normal, so it's a little more tricky for me. Large blocks of solid colours are easy for me. I can distinguish between brown, red, orange, yellow and green fairly easily, in a well lit area. I struggle with darker shades of green, red and brown, subtle differences between shades of orange and green, poor illumination and small objects. I remember confusing the yellow stripe on a blue resistor for green. It was only when a college pointed it out to me and I looked at it through a magnifying glass, did it become obvious to me it was yellow.

On the flip side, there is some evidence to suggest those with deuteranomaly may be better at distinguishing between blue and green, than those with normal vision, since their green cones are shifted towards longer wavelengths, blue will stimulate then less, than those with normal colour vision.

Berni:
Im not color blind but i still find reading the colors on those blue metal film resistor pretty much hopeless. Quite often the color bands have a bit too little pigment in them so the blue background ends up mixing into the colors, making anything towards red just look like different shades of brown. Something that is very unhelpful given that most bands are yellow or below.

Then again even your usual tan colored carbon resistors are not perfect. Ones that have been running hot for a long time tend to darken the colors so orange can look like red, or red can look like brown. Also i noticed that some resistors use a pretty crappy orange color that looks too similar to red. Sure its easy to tell on a 3.3K where you get Orange Orange Red, but grabbing a 33K where its Orange Orange Orange can look a lot like a 2.2K where its Red Red Red

GerryR:
A 5X eye-loop makes everything a lot clearer, even against the light blue background.  Also, I always double-check with a meter if taking resistors out of a "pile" and not from the boxes they came, and are filed, in; keeps the smoke inside more often this way.  ;)

Navigation

[0] Message Index

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod