vu meter led bar graph

[zsolt1]

hi,
the lm3915 is ok, and the schematic on your first post seems ok too. Try to connect the vumeter with a series capacitor added on the input . The cap will stop the dc component of the signal to get in your ic and only the audio signal will pass to it. Experiment with some caps like 100nF ....4.7uF. I personally built a 6 led vumeter with discrete components years ago.... i connected the vu meter thro a 1 uF cap directly to a 8 ohm speaker pads ... anyway yours with the modern Ic and 10 leds should be more fancy :wink: , with your 50 k potmeter you can adjust the maximum scale hed according to your amplifiers max. output .

 

[Kripton2035]

I'm pretty sure you won't have 120v at the plugs of a loudspeaker ... your measuring instrument must be wrong or inadapted for that ?

 

[kik]

im sure aboout the voltage because i got a good amplifer and its very stong and i measure it with my multimetrix
please if someone had shematics and pcb please help me and if someone can tell me when i buy this kit because really i like to make the room good looking with music
because really i want it

 

[zsolt1]

im sure aboout the voltage because i got a good amplifer and its very stong and i measure it with my multimetrix
please if someone had shematics and pcb please help me and if someone can tell me when i buy this kit because really i like to make the room good looking with music
because really i want it

What Kripton2035 is referring to is that it's unlikely to have 120v on a 8 ohm speaker, because that would be 120/8=15 A , or if i remember correctly the formula 120^2/8 =1800 W audio power ...... anyway... probably u used a DVM or other general purpose multimeter so the 120 v value is irelevant . For a correct measurement of the voltage on the speaker you need an electronic voltmeter ... in an other way you don't need to measure nothing , just build the vu meter and adjust it by 'ear' , the visual effect would be great . Unfortunately i can't serve you with schematics these days because i have a lot of work to do and little time .... Try on google, post & ask about it on the forum if anyone knows about it or wait for other responses to you post, they are a lot of audio experts around here :wink:

 

[Kripton2035]

simple : what is the brand and model of your power audio amplifier ?

 

[kik]

good morning every body
please somebody help me to realize this project i found on google this project( https://www.pira.cz/enbar.htm ) but it doesn't work with me please help me
if somebody made a similair project please send me the schematic im really very confused
all my regards