help regarding audio spectrum analyzer using active filters and lm3915

ronsimpson said:

1) the LM3915 is built to drive LEDs not a transistor. Change R2 from 100k to 10k or maybe 1k to get the transistor to turn off.
2)I do not know what your VCC is. You have VCC across 3 LEDs with no current limit resistor. This is a bad idea. You need a resistor to limit current in the LEDs.

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I would be using regulated 9.8-10v from 12 v source so i guess i wont b requiring resistor,
And ok would try 10k resistor value thnx

Please learn about the basics of electronics.

GEEEZ. There should be a separate website for theez nOObs who know NOTHING about electronics!

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Well mr AUDIOGURU, no one is perfect , m not experienced like u ur 30 yrs older then me,
There must b a time when u were having much lesser knowledgethan me, no one is born with knowledge nd u were also not born with it........

If u fell so much irritated nd u feel proudy for having knowledge then u should go and join some other website for irritated nd frustrated people like u.....Or u should not reply. ... No one is forcing you u to reply my questions or any ones question whoom u seem to be a noob

I always respected nd thought you love to help people, i dont know how u managed with your own children when they used to ask simple nd silly questionssss..... I am sorry to say all these words

But whatever i said is true nd u hurted my feelings..plz dont call urself COOL DUDE

If i was at ur age with experience likeu, i would help even that person who does not even know the A B C... Of electronics cz i awnt forget that i even learnt from a scratch one day.......

Have a great day

ronsimpson said:

Two things I can think of.
1) bread board problems causing oscillations. You may have a opamp or LM3915 oscillating. OR Ground noise. Power power supply noise.
2) the capacitor in the peak detector needs to be larger. That will hold the value longer. Try a much larger cap and see if it helps.

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i used 330 nf cap instead of 100nf cap and now its working very smooth thnx

ronsimpson said:

1) the LM3915 is built to drive LEDs not a transistor. Change R2 from 100k to 10k or maybe 1k to get the transistor to turn off.

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thnx , it worked ....soon would post images after project completes