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Posted By: gfretwell LED controllers - 07/22/11 05:22 PM
I am signed up for a Digikey newsletter and there is an article about a new chip for controlling LED lamp replacements for incandescents.

It can give you an idea about what is going on in these things. It sure is more than a string of LEDs and a resistor.

http://reference.digikey.com/TZ/lighting/TZL112.US/WebProject.asp?CodeId=7.4.4.12&pagelabel=55
Posted By: HotLine1 Re: LED controllers - 07/23/11 01:52 AM
Greg:

I was never one for any electronics, further than a very short stint with old component type boards with resistors, caps & a transistor or two.

The evolution of electronics does not cease to amaze me. The vast scope of 'things' that are available today and a 'smartphone' that does many tasks.

The LED advancements are also amazing. LED lighting is progressing quickly, I see more and more being installed from the convenience stores to some high end office spaces, to signage.

Personally, I opted for LED UC fixtures for my new kitchen, for longevity, and no 'heat' compared to zenon.
Posted By: JoeTestingEngr Re: LED controllers - 07/24/11 02:52 PM
http://www.ti.com/ww/en/analog/led/slyt394a.pdf

Greg,
Check out this link for just TI's options. I D/L'd it last year when I was working on a design with my brother. Most use boost or buck switchers with FETs and small current sense resistors and include dimming inputs. My main problem is that it's harder and harder to find PDIPs or CDIPS and I detest surface mount. I get the EDN emails at work and all Im'seeing is LED lighting. There is a lady there who tears down new incandescent replacements that comes along. I'll post a link later.
Joe
Posted By: gfretwell Re: LED controllers - 07/24/11 05:45 PM
SMT seems to be the wave of the future, great for mass production but it is sure tougher for the garage inventors to deal with. When I am futzing in my shop I still like wire wrap sockets and dips.
I'm still stuck in the 70s tho with 4xxx CMOS, ancient linears like my beloved LM324 and the transistor with all the 2s in it wink
Posted By: n1ist Re: LED controllers - 07/24/11 10:45 PM
SMT isn't that bad; I routinely do SOIC and 0603 parts at home. The cheap Chinese PCB houses certainly put an end to wire wrapping, however...

Radio Shack still carries etchant, and toner transfer lets you do quick boards at home too. SMT eliminates drilling all of the holes.

/mike
Posted By: JoeTestingEngr Re: LED controllers - 07/27/11 02:06 AM
Greg,
I replaced a 44 pin square SMT IC on an MII machine TBC board about 20 years ago at the TV station. I sweated bullets then when I could see. Now, I have several bad I2C D/A SMTs on display boards that I need to deal with. It figures that the one bad chip on the board is the only surface mount, and that they stuck it right next to taller thru-hole components.
I never gave much thought to my fav. IC's and transistors. I guess probably the 4013, 4017 & 4066 in CMOS. The LM339 edges out the 324 for me. I've sure enjoyed using ULN2003s and 4s for drivers. I use a lot of BS170s where I used to use all those 2s, especially when I want to use the gate circuit to sense something. The LM555 can't be forgotten for timing.
Mike,
I just tend to breadboard circuits in the lab at work(or at home). Then, I use Generic CADD & Dyna Arts ---> Impulse toner transfer for the board. I've always ordered our copper clad, etchant, and tin plating solution from Newark but I've never done any large volume. Its just nice to layout a board and be able to have it stuffed and tested the same day. I've used Advanced Circuits in Colorado, and their free "PCB Artist", for any volume or double-sided stuff with small traces or lots of vias.
I keep one wire wrapped circuit around for old time's sake. I built it in '89 to interface a Grass Valley editor to a Chyron character generator. It has a UART and lots of 74LSxxs in it. I keep it in the cupboard beside my Commodore 64.
Joe
Posted By: gfretwell Re: LED controllers - 08/05/11 01:09 AM
Here is another article about exactly what is in a LED lamp.

http://www.eetimes.com/design/smart...What-s-under-the-frosting-semiconductors
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