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How do I power a spectrum analyser? Answered

I want to make an audio spectrum analyser using 8 lm3915 IC chips and 4 TL072 chips with a TL071 amp for the TL072 chips. The TL072 chips will be wired into bandpass filters of different frequencies, which will output into the individual LM3915 chips. These ICs will be wired as VU meters. The outputs will be these LEDs:
I would also like to add a feature of adding a feature where when the ambient light is lowered, more lights turn on using another LM3915 chip.
Another feature I would like to add is an amplifier and I want the spectrum analyser to respond to background music via a microphone and a pre-amp.
The circuit I am going to use is:
Finally, I would like to ask If this is plausible and what power supply should I use?
It must be able cope with the power demands of these features.
The power supply has to be from rapid electronics, because my school can only buy from rapid.
Also, I would like to know what power amplifier I should use (25w, 30w, etc).
Thanks! (I don't want to use microcontrollers, because I want to make my spectrum analyser look cool by showing the electronics (microcontrollers look simple)


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8 years ago

The LEDs will completely dominate your power requrements. Once you have your demanded current, for 10 LEDS on 8 chips at 20mA/led, you have a number to work with.