Metku.net

MetkuMods
It is currently 22.09.2018 12:34

All times are UTC + 2 hours [ DST ]




Post new topic Reply to topic  [ 6 posts ] 
Author Message
PostPosted: 05.12.2007 23:33 
Offline
Junior Modder
Junior Modder

Joined: 05.12.2007 23:10
Posts: 4
I've build this circuit following both the model done by Bill Bowden in 01 [the cross fading LED pairs version] and the layout from Colorfade as well, both using a breadboard prototyper.

The 4 LEDs are 10MM 3V superbright blues
The IC is an LM324N
The caps are both 22uf
The transistors are 2N3904 and 2N3906 as Bowden used
All the resistor values are right, using the set resistors, no pot yet.
Powered by a variable voltage mains power supply running at 9V
[supply has been tested, its actualy 8.8V]

My problem is simple... its not working and this being my first build in about 16 years, I am totaly lost as to where I'm going wrong.
I've made sure none of the componants are shorting and I've rebuilt a dozzen times, but every time I'm left with :

The 2N3906 LED couple are at full brightness
The 2N3904 LED couple are fully off
And thats how it stays.

I've tried turning the caps around, removing one LED from each couple, changing the timing resistor... all had no effect what so ever.

Any advice would be greatly appreciated, before I rip out too much hair in frustration.
:(


Top
 Profile  
 
 Post subject:
PostPosted: 06.12.2007 00:09 
Offline
Site Admin
Site Admin
User avatar

Joined: 24.01.2002 10:09
Posts: 4683
Location: Finland
If I may ask, how come you have two caps as the schematic only needs one? And did you notice that it has to be electrolytical condensator with polarity.

_________________
Metku | AlltheMods | LedCalc | Teknolelu | AndroidCoding
Main Computer: Intel i5, MSI H55M-ED55, 12 Gigabytes of DDR3, 3 Terabytes of HDD, GTX295 and Benq 27"


Top
 Profile  
 
 Post subject:
PostPosted: 06.12.2007 00:23 
Offline
Junior Modder
Junior Modder

Joined: 05.12.2007 23:10
Posts: 4
I only used one cap in your version of the circuit, Japala, but in Bowdens one I used two, following this diagram :
Image

I think I'm using the right caps, as I said its been a long time since I did anything in electronics.
The caps are both 22uf, 50V, with a white stripe down the short leg side with - signs along it.


Top
 Profile  
 
 Post subject:
PostPosted: 06.12.2007 01:25 
Offline
Site Admin
Site Admin
User avatar

Joined: 24.01.2002 10:09
Posts: 4683
Location: Finland
Yes, should be right ones... are the caps "fresh"? If they are old, they may have lost their properties and do not fuction correctly. Also, if I remember right, there were a used that had problem with the transformer. It wasn't giving out proper DC so the circuit didn't work. If you have batteries, test the circuit out with them first.

_________________
Metku | AlltheMods | LedCalc | Teknolelu | AndroidCoding
Main Computer: Intel i5, MSI H55M-ED55, 12 Gigabytes of DDR3, 3 Terabytes of HDD, GTX295 and Benq 27"


Top
 Profile  
 
 Post subject:
PostPosted: 06.12.2007 02:50 
Offline
Junior Modder
Junior Modder

Joined: 05.12.2007 23:10
Posts: 4
All of the componants I have were bought last week from eBay, the supplier seems reputable and his prices seem quite decent, for those interested his shop is at http://stores.ebay.co.uk/Bitsbox-Electronic-Components

Most of the componants, including the caps came from him, and as its his business selling bad components wouldn't be a good idea.

As for the power supply, I will try batteries, a PP3 9V cell should be suitable?
I'll let you know how it goes.


Top
 Profile  
 
 Post subject:
PostPosted: 06.12.2007 03:34 
Offline
Junior Modder
Junior Modder

Joined: 05.12.2007 23:10
Posts: 4
Rebuilt using the Bowden circuit and powered with a 9V cell.
The second LED on the 2N3094 couple is a dim green
The first LED on the 2N3096 couple is barely lit, blue
There is no fading at all.

What would be the best way to test the capacitors?
Thinking I may have damaged something, I've tried replacing both transistors and the LM324, and met with the same result


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC + 2 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group