EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: dave_j_fan on August 13, 2016, 05:11:48 pm
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CAn led vu meter run offf headphone audio,
means I want to boost the audio signal to say 6v and run the VY circuit ( trasistor typ)
will be fun add on to phones laptops
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LED? Probably not except for maybe some very high efficiency LEDs run at very low currents, maybe not even well visible in room lighting.
If you used a very low energy CPU like some MSP430 or STM32L / Kinetis L series part and the right energy harvesting setup you could probably power the MCU enough to process the audio in real time, or you could use some low power analog VU circuit. But the display will likely take more power than everything else and be challenging or impossible.
well its a doable thingy ....avoiding vv special chips is one aspect of the design
thank u for the reply .i have good and bad news
a 5mm normal red LED gave nice glow via JT circuit
on a iphone5 with volume full
sadly if we load the audio lines with headphone it doesnot work
Not much point to do it externally except as toy novelty a since the phone itself could very well display a VU meter on its screen.
luv physical vu!
As of now such a thingy will run on speaker wires with a small amount of tweaks ( planned to make on the headphone out .. will wait till someone give a trick )
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Audio amplifiers are designed to drive linear headphones and speakers. A VU meter LED display circuit draws high current pulses that will cause severe distortion to the audio output.
Use a rechargeable or disposable battery to power the VU meter circuit instead.
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concept was a stand alone..but seems itz not that simple .
yes distortion will add up ...