4 Channel LED colour organ not working

Thread Starter

Max12345

Joined Aug 27, 2013
63

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tubeguy

Joined Nov 3, 2012
1,157
+1 If you were using a 12VDC supply you should see about 0.43VDC on those transistor bases; the LED's would be off with no audio signal.
Wild guess > are the 270K resistors the correct value (270,000 ohms)?
 

Thread Starter

Max12345

Joined Aug 27, 2013
63
Hi guys
Alec_t, the supply is 12V.
Tubeguy, the 270K resistors are correct as per Ledartist's circuit.
I have uploaded ALL the base voltages on the new "Original and changes 2" schematic for your perusal.
Thanks so much
 

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Alec_t

Joined Sep 17, 2013
14,280
Those voltages are seriously not what they should be. Double-check that you have the pin-outs of the transistors correct.
 

MrChips

Joined Oct 2, 2009
30,712
I agree. There is something dramatically wrong with your setup.
Post clear well focused photos of both sides of your circuit board.
 

tracecom

Joined Apr 16, 2010
3,944
Assuming that there are no faults on my veroboard...
When my prototypes don't work, my first assumption is that there IS something wrong with my wiring. Using a marked up schematic increases the likeliehood that something is wired wrong. The easiest thing to double check is the pin out on the transistors; viewed from the flat front, the leads are l to r, c, b, e.

Did you breadboard the circuit before you put it on veroboard?
 
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Thread Starter

Max12345

Joined Aug 27, 2013
63
Gents, you've found the problem (sheepish grin).
I used the P2N2222A pinout configuration for the KSP2222A and they are not the same! My transistors are connected wrong way round.
The store at which I purchased the transistors has a datasheet of their transistors and when I clicked on the sheet for the KSP222A, the sheet of the P2N2222A came up and I assumed that they were identical. Assumptions...

http://www.mantech.co.za/Stock.aspx?Query=ksp2222aand


Tracecom is correct in his layout of the P2N2222A, although I think that the 2N2222A is a can. That is the way I have it on my vero.



So are they all shot now? Or should I still bother to check them before buying others?






 

Thread Starter

Max12345

Joined Aug 27, 2013
63
When my prototypes don't work, my first assumption is that there IS something wrong with my wiring. Using a marked up schematic increases the likeliehood that something is wired wrong. The easiest thing to double check is the pin out on the transistors; viewed from the flat front, the leads are l to r, c, b, e.

Did you breadboard the circuit before you put it on veroboard?
I didn't, my breadboard is too small...(another sheepish grin)
 

MrChips

Joined Oct 2, 2009
30,712
Well, Alec_t had said it first. I looked at your photo and figured you had connected it correctly.
I reversed the pinouts in a simulator and did not arrive at your values. So I assumed that you had another problem somewhere.
 

Thread Starter

Max12345

Joined Aug 27, 2013
63
Well, Alec_t had said it first. I looked at your photo and figured you had connected it correctly.
I reversed the pinouts in a simulator and did not arrive at your values. So I assumed that you had another problem somewhere.
So he did, MrChips, so he did. Thanks Alec_t.
I'll whip 'em out and replace them and see...
Thanks again
 

tracecom

Joined Apr 16, 2010
3,944
Well, I was confused as well. I keep and use the PN2222A, which has a l to r pinout of e, b, c. My mistake was in not realizing that the 2N2222 is a can with a different pinout; I thought they were just two different numbers for the same thing. When I looked at the photo, that confirmed my erroneous belief, all of which is the reason I posted wrong info about the 2N2222 and had to correct it. Thanks to MrChips. :)

I am sorry for any confusion I caused, but I learned something I won't soon forget.
 

Thread Starter

Max12345

Joined Aug 27, 2013
63
Probably not. Re-connect them right way round and give 'em a try.
All the transistors worked, except 1, which also worked, but only dimly switched on the LED in my transistor tester, so I replaced that one.
Circuit works now, thanks.
However, now I have to work on the filters. A link to a sound card generator given to me by bertus, shows that there is too much overlap between the bands.

http://www.twopaths.com/Software/index.htm
 
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