op amp (filter)

[conductor3]

i am new to this but i know alot about electronics. my dad says i know stuff other people take 4-5 years of college to learn but still don't understand. well..................................i need help! i need help building a light(led) organ made with op amp filters but don't know how to build one........................................can some one give me a diagram







thx..........
conductor3

 

[Windadct]

Do you mean a Light ( Color) Organ that turns lights on / off with the music - or something else.

Can be done with out op amps, just passive filters and SCRs, but a number of schematics I just googled show some with active filters ( op amps). This is a pretty common electronic kit as well.

 

[poor mystic]

Hi Conductor3.
You need to learn about filters. Filters are circuits that let a particular range of signals through and block others. The frequency of the signal (how many cycles per second it is) has to be right for the signal to get through the filter.

Different sounds have different frequencies, so different filters will pass a signal when different sounds play. At the output of each filter an electronic detector circuit detects the information that a sgnal has been passed through the filter.

In a colour organ the electronic signal representing music is arranged to enter several filters. The outputs of the filters are used to control lights of different colours.

 

[conductor3]

thanks so much for your help but can you please send me a diagram with the input op amp ....................................if you know what i mean thanks again


conductor3

 

[davenn]

thanks so much for your help but can you please send me a diagram with the input op amp ....................................if you know what i mean thanks again

conductor3

what searches have you done so far ?
have you tried google ? its full of circuit ideas

Dave

 

[poor mystic]

Where will the input come from please, conductor3? What kind of signal does the op-amp circuit need to accept?

 

[conductor3]

what searches have you done so far ?
have you tried google ? its full of circuit ideas

Dave

yes but i had no luck at all

 

[conductor3]

Where will the input come from please, conductor3? What kind of signal does the op-amp circuit need to accept?

input=3.5mm headphone jack from stereo
signal=one for low,medium,and high signals
kind of light bulb=LED

 

[(*steve*)]

Is this the sort of thing you're looking for?

I googled for "music colour LED display schematic"

 

[conductor3]

Is this the sort of thing you're looking for?

I googled for "music colour LED display schematic"

yes but no i need one using filters ....................but i'll try it

 

[poor mystic]

...why do you want a filter please, Conductor3? Is this for a bet?

 

[(*steve*)]

yes but no i need one using filters ....................but i'll try it

That *does* use filters.

 

[poor mystic]

...if I designed a filtering colour organ using a few opamps and a transistor and a couple of led's would you be able to build it?



(I'm thinking of buffering 1 channel into a twin-T followed by a charge pump. Then it would get inverted and fire a transistor)

 

[poor mystic]

How you you plan to power your colour organ please? Will it be batteries, or...? What voltage will be available?

 

[conductor3]

How you you plan to power your colour organ please? Will it be batteries, or...? What voltage will be available?

batteries =6 volts

 

[conductor3]

That *does* use filters.

transistors can be used as filters .............you learn something new every day

 

[conductor3]

...if I designed a filtering colour organ using a few opamps and a transistor and a couple of led's would you be able to build it?



(I'm thinking of buffering 1 channel into a twin-T followed by a charge pump. Then it would get inverted and fire a transistor)

yes that would be fine if it has 3 channels

 

[conductor3]

...why do you want a filter please, Conductor3? Is this for a bet?

to control leds to decorate my room

 

[Windadct]

With Op Amp Input and Filters

Hello Conductor3 - I found this relativly easily LINK

 

[(*steve*)]

transistors can be used as filters .............you learn something new every day

We all do.

In this case the combination of resistors and capacitors are the parts that define the filter frequency. The transistor(s) provides gain to offset the losses in the filter.

In general, the passive components (capacitors and/or inductors typically combined with resistors) set the frequencies and amplification is added to buffer impedances or to provide gain (or less loss).