project..need help

[baftab]

here i go again
the schematic in my first post is my project
it needs audio signals so tht the LEDS may blink accordingly
i hav a cd player ...not a cd man....it has built in speakers ..plus the speakers i use with my PC alslo work with my player...
all i hav to do is put the pin in HEADPHONE socket and the external speakers start working while the built-in ones stop

if i remove one of the speaker from external pair of speaker and inplace of it i give the output to my project...will it work????

i hope i hav made myself clear this time...if not..please ask what you want to know...because i realllllyyy neeed help
thnx

 

[Joel Rainville]

Ok, so all this time I was using amplified soundcards without knowing it... Great I did need more than 1W most of the time, but I bet it would have been useful to know from time to time

I think that what the original poster is trying to do is merely feed the amplified output of his stereo to both his project and external non-amplified speakers. He is suggesting taking the output from one sterep channel (say Left) and feed that to his project, leaving the other stereo channel (Right) go to his speaker. That's what I thought would sound worse than a mono audio signal. What he really wants to do is split the stereo signal to feed both his project and the external speakers...

 

[Nigel Goodwin]

Obviously it's hard to know what's best without seeing the actual gear, and we've no idea of signal levels or impedances!.

As 'baftab' looks to have very little experience?, I think the 'one channel' solution is probably the best for him.

So I should try unplugging one of the speakers, and feeding the output from your CD into your circuit - this should work fine, but you will only hear one channel from your CD, and see the display from the other channel.

Once that's working you could try connecting your second speaker as well, due to the relative impedances you should be fine connecting both your circuit and the speaker in parallel to the output of your CD.

I won't worry about only one side feeding the display!.

 

[baftab]

joel...u got it right
thts exactly the problem i am facing
my project will b completed tomorrow..so hopefully i'll b testing it and will know whether it will work or not

thnx a lot both of u..NIGEL and JOEL u guys hav been great help

thnx thnx

 

[audioguru]

If i play a cd in my computer system and connect one of the speaker's wire with the my project's input....will it work???

The audio output jack on your computer is probably a stereo 3.5mm type. You need to add a splitter cord that has one stereo 3.5mm stereo plug from the computer, a 2nd plug for the amplified speakers and a 3rd plug for the circuits.

To display stereo you need two of these circuits, or you can modify one circuit easily to include a mixer for the two stereo channels. :lol:

 

[audioguru]

Wait a minute!
Deja vu, deja vu. Someone recently asked about that circuit, was it you?
Hee, hee. I am a poet again. :lol: :lol:

The schematic for that circuit has errors with the wiring of U2, U3 and U4.
Look at Panasonic's application circuit on its datasheet.

 

[baftab]

yeh tht was me..
i think you are right...
because my LEDS are lighted but are not blinking
i'll change its configuration and try again

thnx

 

[baftab]

thnx audioguru...
my project is working

can u briefly describe its working?
i knw U1 is buffering..and U2,3,4 are norton amplifiers

its a VU meter,,right?

 

[audioguru]

Great! You built it, you fixed it and it works. :lol:
Lookup Comparator Circuit in Google to see how it works.

 

[baftab]

comparator? arent they multiple feedback,bandpass filters???

 

[audioguru]

No, a comparator isn't a filter.
It has two inputs called differential. One is its DC reference voltage and the other is the signal which is reduced by a voltage divider pair of resistors. A comparator has a huge amount of voltage gain for any voltage difference between its inputs. Therefore it compares the divided signal with the reference voltage. When the divided signal's level exceeds the reference voltage then its output changes to the other state.

 

[Marconi]

comparator? arent they multiple feedback,bandpass filters???

Quick Question,

In the bottom right hand portion of the circuit diagram is C18. Does anyone know what the value of this capacitor is? It isn't on any of the diagrams or parts lists I could find on the web.

Thanks,

Mike

 

[audioguru]

Aaron corrected his schematic with my corrections. I think he also inserted a value for the supply filter capacitor C18. It can be from 10uF to about 100uF and its actual value doesn't matter.

 

[Marconi]

Aaron corrected his schematic with my corrections. I think he also inserted a value for the supply filter capacitor C18. It can be from 10uF to about 100uF and its actual value doesn't matter.

Thanks a lot for the quick reply. I really appreciate the help.

Mike