Trying to dim LED with POT

Thread Starter

Deric

Joined Feb 8, 2010
25
Sorry Wook. I saw that in the signature but thought it wasnt a big enough topic to start a thread on that one comparator that was specific to my circuit.
So do i even need to buy that comparator that it shows doing nothing? or are all those comparators one single unit?
 

hgmjr

Joined Jan 28, 2005
9,027
As you are beginner I think you should go for a pre drilled prototype board. At the point you are now these boards are best. You can get them in many variants. With solder pads or stripes in one side. I like stripe variant best, and I use a drill bit to cut tracks. You can even get free programs helping you with the layout.

I agree with t06afre's recommended prototyping materials. I have had good luck with these materials in my own breadboarded projects.

hgmjr
 

SgtWookie

Joined Jul 17, 2007
22,230
Sorry Wook. I saw that in the signature but thought it wasnt a big enough topic to start a thread on that one comparator that was specific to my circuit.
A common misconception. You were most definitely not the first, nor will be the last.

The whole idea of this Forum is the sharing of knowledge. If help is given via PM or E-mail, only one person benefits from that knowledge - besides, the information you receive via PM or E-mail may be in error if no one else reviews the info before you act on it.

I am not perfect; I do make mistakes. There are also many other possible approaches than one person might present. Conducting such discussions in open forum benefits you, and a great many others as well.

It also keeps my PM's and E-mail from getting completely jammed up. I no longer even reply to E-mails I receive from the forum (unless I've known them for awhile) as it frequently results in more spam E-mails coming my way.

So do i even need to buy that comparator that it shows doing nothing? or are all those comparators one single unit?
The LM339 is a quad comparator; it has four individual comparators in a single IC. One reason that I used that particular comparator is that they are available practically everywhere on the planet, and are very cheap. If you want to pay top dollar for one, you can get one at your local Radio Shack store - even there it's less than $2.

I could have specified using a dual comparator plus a single comparator, or three single comparators, but that would have been more expensive and a lot more wiring.

Generally, you want to go for the level of integration that will satisfy your project. Having one unused comparator out of four is a very reasonable sacrifice for the added convenience and reliability of dealing with just one IC.
 

Thread Starter

Deric

Joined Feb 8, 2010
25
Ok, that makes sense. I also didnt know if you were still checking this thread or not.
I figured out the comparator after i asked that question. I think i have it all figured out and i have a few of the peices necessary to build this. Thanks for all the help so far.
 
Top