106Views2Replies

Author Options:

In search of LED 101 Answered

First of all, let me apologize if the questions to follow seem stupid in any way, and that those stupid questions have been covered somewhere else. I am trying to learn a few basics in the LED world, and to most people here, I would be classified in the "uber-uneducated" category. My first question is about timers. I have seen many topics covering "flash rate this" and "blinking sequence that". Are timers (555? PIC? etc) pre-programmed pieces, so that when you install (correctly), they go about their merry functions, or is there something I need to know otherwise? I have seen tuts about POV which I believe is something that needs programming (obviously for designs), but where/how do I obtain the knowledge and/or equipment to perform such tasks (PC program, the little thing to hook it up to PC, etc)? I have seen consumer items with "variable" blink/flash patterns, like 5, 3, 2, 4, then it repeats. Is this the same, or....? (perfect example would be those like flashing LED police/fire/ems lights) Can flashing/blining be obtained by adding simple transistors (is that the piece im describing?) in the sequence? Another question I have is about the LED specifications in general. When I see LED's offered for sale in places like eBay, or where ever, I see listings for XXX mcd. Am I correct in assuming that this is the so called "brightness" of the item? I want to build projects that have high visibility, but not at the cost of an arm for some of the items I have seen for the higher rated XX,XXX mcd. These are just a couple of many questions I have, and there are so many great projects here, any help in LED 101 would be greatly appreciated. I have learned alot already, I just need a few basic pointers. Thank you for letting me waste your time :)

Comments

The forums are retiring in 2021 and are now closed for new topics and comments.
0
Kiteman
Kiteman

13 years ago

First, welcome to the site, bullard.

Second, I'd like to apologise for "bommber man's" response. You'll find that the vast majority of members are far more mature and helpful than that

Thirdly, don't be ashamed about not knowing the basics of a subject - we all have areas like that.

Fourthly, 555 chips are not programmable as such - they're action is controlled by the sizes of resistors and capacitors that you add to them, and yes, the "mcd" is the brightness of the LEDs (it's short for "millicandles").

For more useful information by more experienced Makers, check these two Instructables:

https://www.instructables.com/id/Minty-Beating-Valentines-Heart/
(a basic 555 project, with links to other useful information).

https://www.instructables.com/id/LEDs-for-Beginners/

If you want more projects using 555s and LEDs, then look to the top-right of the screen - that's where the search box is.

0
bullard
bullard

Reply 13 years ago

Thanks Kiteman, the links are very helpful.

0
Kiteman
Kiteman

Reply 13 years ago

Any time.