Electronic Projects, forums and more.

Go Back   Electronic Circuits Projects Diagrams Free > Electronics Forums > Electronic Projects Design/Ideas/Reviews


Electronic Projects Design/Ideas/Reviews Are you building an electronic project or want to? Maybe you need some assistance? Come and submit your electronic questions here and let our experienced members find a solution.

Reply
 
Thread Tools Display Modes
Old 12th January 2008, 12:39 AM   (permalink)
Default planning to build audio gear--HELP

planning on building a lm3886 chip amp, a BA3812L graphic equalizer and a VU bar graph meter(lm3914/15/16??)
which goes first the equalizer then the apm then tap into the outputs for the vu meter??
which bar graph driver chip=3914,15,16?
buying the lme889 chip amp kit. just need toriod transformer.
designing pcb for all but amp and power supply as the kit has these.
need advice etc.
MrDEB is offline  
Reply With Quote
Old 12th January 2008, 01:46 AM   (permalink)
Default

The LM3914 is a linear voltmeter. Low level audio is down only 20dB and the steps are huge. The steps at the loud end are crammed together.

The LM3915 has a logarithmic response the same as your hearing. Its lowest LED lights when the output is down 30dB (1/1000th the power) and each step is +3dB and is double the power. I have one with two LM3915 ICs cascaded for a 60dB range.

The LM3016 is an odd-ball. The low volume steps are far apart and the loud steps are close together, something like an LM3914.

The datasheet for the LM3915 shows two Peak Detector circuits. Without a peak detector then the level is jumping all over the place in real time which results in the LED display being a dim blur. The peak detector has a fast attack then a slight delay before dropping so your eyes can see the peaks.
__________________
Uncle $crooge
audioguru is offline  
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Latest
Audio / sound injection for in car computer KCarPC75 Electronic Projects Design/Ideas/Reviews 1 5th January 2008 07:08 AM
Speedometer Kiko Micro Controllers 131 29th November 2007 05:33 PM
Coupling with an audio output fvnktion Electronic Projects Design/Ideas/Reviews 3 5th February 2007 09:37 PM
Gear Indicator.(need help to build one) zx16v Electronic Projects Design/Ideas/Reviews 13 7th October 2006 06:08 PM
Audio Amplifier Designing Project silverferro Electronic Projects Design/Ideas/Reviews 3 26th August 2004 10:04 AM



All times are GMT. The time now is 07:53 AM.


Electronic Circuits  |  Electronics Wiki
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.