hello, could the LM3914 be used as a VU meter, i would like to add a few to some speaker boxes


heres the data sheet
http://cache.national.com/ds/LM/LM3914.pdf

 

You'd be far better off using an LM3916, because it's designed for use as a VU meter.
The LM3915 is logrithmic, the LM3914 is linear.

 

ok thanks, i already had the LM3914 so i was just wondering

 

I suppose that you could use it, but you would have to pre-process the input, perhaps using an opamp and associated components. It really would be more trouble than it's worth.

Jameco.com has LM3916N/NOPB's available as 4-day dropship for $1.59 each. They don't have a minimum buy.

Save yourself the hassle of trying to beat a square peg into a round hole. Unless, of course, you really want to tackle something like that, and don't mind spending lots of time fiddling with it.

 

I designed a Sound Level Indicator project with an electret microphone, a preamp and an LM3915 driving two LEDs in series on each output. The LM3915 has a logarithmic detector like your hearing and I enhanced it 20dB with a simple compressor circuit when sounds get loud. So it is extremely sensitive and shows a pin dropped on the floor of the next room and also shows very loud sounds.

An LM3914 is a voltmeter. It does a poor job measuring sound levels.

 

ok thanks guys