it's been abotu 20 years or so since i've needed to know what was what and why they are called what they are called, so this morning i've got some questions to prepare me for the weekends activities

led's
what are the 2 legs called?
and which one is the positive? the longer one right?

resistors
which way do they flow? towards the single line right?

i know i could google the answers but i'm crap at that and none of the sites i've looked at have given me the answers i'm after

so thanks kind chaps and chapesses for answering

 

LED, have ANODE and CATHODE
ANODE = POSITIVE, CATHODE = NEGATIVE.
Resistors ?, I assume from single line you mean RECTIFIER DIODES ?, if so the line depends on which way you want current to flow/not flow.
If flows easy through the line nearest but not the other way.
Resistor orientation is unimportant as they don't have one, they work either way.
tabetha

 

resistors flow both ways, so no polarity. The Single line is normally gold, which shows the tolerance of the resistor value. There are other colours but ive forgotten them lol

 

The 'single line' as you call it on a resistor is the tolerance value, 5%, 10% etc.

 

and on the led the longer leg is the anode

 

if you look into the LED one leg will be connected to a much larger plate inside the actuall led, this is the cathode so the larger plate is the negative and the tiny plate is the positive,
thats how you find out if the legs have been trimmed down.

 

yes indicated by a silver or gold band depending on the tolerance of that particular component. silver is 10% and gold is 5% usually.

 

yup, longer ones are connected to the smaller plate so that's fairly easy for the led's

the resistors thoguh:

they've got 5 lines on them, 4 do the vaule if i can remember that far back and the other line should be gold silver of bronze to tell you somethign else corect?

these don't though

they've got a red line, then a gap, then 2 black lines, a grey line and another red line grouped together
they shuold be 270ohms

but which waydo i solder them?

 

As above, any way you like!

 

i've got a drawing drawn up to tell me what i need to do then

thanks all who participated in this helpfull post

 

red grey black, then the multiplyer line. then the tolerance.

270+0 and a 2% tolerence. solder them any which way you like

 

Yup they can go any way round, however when I was doing electronics at college I was always taught to mount them the same way round as each other, just makes the job look a bit neater!

 

http://www.csgnetwork.com/resistcolcalc.html

try this for resistors

 

dojj,

Whilst I appreciate not everyone understands these things....

The thought of a directional resistor just made me spit my tea over my keyboard

 

maybe i'm thinking of something else then

it's been the thick end of 20 years since i had to do this thing for a living

 

Thinking of a diode?

 

pissibly, although that's probably soethin else i'veforgotten about in the course of the years

i've got a b/tec certificate somewhere, with a pass rate of over 85%, in electronics, i shouldn't be forgetting this stuff, should i?

 

No, not really..

 

A btec? Fuck me i got a btec at college for having the highest attendance rate in the class I knew fuck all about the subject

 

i got a c&g 224 ... but cant remember a single thing