LM3915 IC LED VU Meter Tower

Description : This was based on an LM 3915 IC and also worked well with an LM 3916 IC. These were bought through eBay
Built using 10 - 10mm thick plexiglass sheets purchased precut to size (5" x 6"), 20 - 5mm LED's (9 colors) wired in parallel for the plexiglass sheets and the arrays also wired in parallel and a 6V DC 1A adapter to power the project. Base of the project was just a wooden frame with some plexiglass added for a top and front panel. It measures approx. 8"D x 7"W x 3"H. Total height of the project is about 15".
Here's the basic circuit I used.
www.eleccircuit...
I also added an LM386 Audio Amp before the input of the above circuit. A 10k pot was used for volume control. A 5mm blue LED was wired to the power switch.
An example of this is shown from another LM3915 circuit.
www.pira.cz/enb...
Pin 6 of the Audio Amp was wired to V+ in the above basic circuit and pin 5 was wired to the "input from amp" side in the same circuit.
The plexiglass was purchased from www.tapplastics... in the US at a cost of about US $40 plus shipping.
Update 7/14/16...The video shows the lowest LEDS in the tower remain dimly lit in dot mode. A fix for this was posted by TheVarooj. Adding a 10k resistor across pin 1 of the IC and V+ will correct this.

[@claudineibento1739]

I want to thank you for your kindness; because it was a mistake on my part. Usually, when showing a job, the person puts the list of materials and their specifications. At least this I learned in this area many years ago.

[@paulstubbs7678]

Nice, I've used the 3915 before, and was looking for "what's next" - a spectrum display?, but after seeing this, all I need is some perspex and some imagination.

[@ODX171]

Hi Paul. Looking forward to seeing what you come up with !

[@linorocha6319]

If you increase C2 you will have a lower descent of the visual signal, for me it works better.

[@ODX171]

Lino Rocha Great to see you changing a few things to work better for you. Mine is currently 47 uf.

[@masterbeetsma]

Lino Rocha ty so much, was looking for this solution, you made my day. made it 10uf too

[@manoharmanu1460]

I would have used a ws2812 strip for this beautiful build you would have more customisation

[@ODX171]

Perhaps if you build this you could share the build for us to view

[@WuXiJin]

Hi can you please list all of the sizes of components please e.g. 47uf 50v

[@tomazvrhovnik3263]

I made it.. but i don't know one thing. The VU meter vorks fine wihout the lm386, but it reaches only up to 5 or 6 leds. Then I wired the lm386 but it doesn't work.. Can you help me?

[@ODX171]

***** Hi. I'm not sure what problem you're having. Perhaps I can help you through email if you care to post it here.

[@shubhkain7544]

can you provide me a full diagrammatic circuit including audio amp...... please. Reply As soon as possible. thank you

[@claudineibento1739]

Please. What size acrylic did you make? Do you have a list of used parts?

[@ODX171]

Can you explain why viewers DON'T take a few min. to READ the DESCRIPTION for more info ??????

[@claudineibento1739]

@@ODX171 I want to thank you for your kindness; because it was a mistake on my part. Usually, when showing a job, the person puts the list of materials and their specifications. At least this I learned in this area many years ago.

[@mazevedo852]

Hi. The leds you used was the normal ones or some special? High Bright? Thanks

[@ODX171]

Read my reply to Qubnix below.

[@tomazvrhovnik3263]

What kind of LED's did you use? Just normal or some kind of high illumination LED's.. Thanks

[@ODX171]

Hi Franc. These are just clear 20 ma LEDs Very Common. Thx for sharing this,

[@tomazvrhovnik3263]

ODX171 Just one more question. Did you use this circuit: www.pira.cz/enbar.htm? Did you made any changes?

[@ODX171]

franc zdoline Hi. Franc. Re read my reply to you that was sent about 3 months ago. You may want to take a min. to re read the description above also. The 386 wiring diagram ONLY was used from that circuit. www.pira.cz/enbar.htm ... Pin 6 of the Audio Amp was wired to V+ in the basic circuit and pin 5 was wired to the "input from amp" side of the same circuit. Have you built this one yet and/or is it working ?

[@tomazvrhovnik3263]

ODX171 Sorry but i can't watch the other video. Somehow it seems to be blocked in my country, so this is why I am asking you again.

[@tomazvrhovnik3263]

ODX171 Just one more question. Did you put any resistors before the 1, 10,...18 pins of the 3915 or did you just wire the LEDs parallel directly. Thank you.

[@priscilla00167]

When it's on bar mode the led connected in the 10 pin is constantly on, what would be the problem??

[@ODX171]

+priscilla00167 Hi. I'm not sure what's causing that BUT it's common to this type of circuit using lm3914/5/6 as shown in many vids on YT. Perhaps a filtering cap or resistor across that pin would eliminate this. I've not tried that. Perhaps someone could comment on a possible fix.

[@ODX171]

Thx to TheVarooj for posting a fix for this problem. A 10K resistor across Pin 1 of the IC and V+ will correct this. kzbin.info/www/bejne/Z53Mf4iCfM98eJY

[@diosleon4346]

Song used while the test?

[@user-qm6js1wf1k]

I want make it .would you plz share the circuits diagram

[@markjosephnavarro7034]

Sir how did you wired a switch to select wether it's in DOT or BAR mode?

[@ODX171]

+Mark joseph Navarro Well...If you read the description you'll see a link to www.eleccircuit.com/electronic-vu-meter-by-lm3914-and-lm3915/ showing the schematic used and how that switch is wired.

[@markjosephnavarro7034]

Thank you sir..

[@sharoner3725]

Hi Sir, this circuit need any program? This is an analog circuit or digital circuit?

[@ODX171]

+Sharon Er If you read the datasheets on the two onboard chips , you'll see they are NOT programmable chips.

[@sharoner3725]

Ok, thanks u :)

[@alissongps]

IMPRESSIVE .. :O

[@leonelfernandes4784]

you can use a strip of 3 leds instead of LEDs as you use?

[@ODX171]

+Leonel Fernandes Are they from a strip powered by 12 V ???

[@leonelfernandes4784]

+ODX171 yes

[@ODX171]

Leonel Fernandes They should work ok. Try it and let us know how it turned out. You could breadboard it first to test.

[@leonelfernandes4784]

+ODX171 Ok thank you. I'll try a strip of 3 leds and tell you how I was

[@SpaceOut26]

where did you get all those diffirent colors of LED's?

[@ODX171]

Most of the parts are purchased thru eBay. Many sellers of LEDs there.

[@gemindrigon5833]

can we add more LEDs sir? or can we increase the height?

[@ODX171]

+Gemin Zennia I suggest you try and let us know how it turned out.

[@toxicblue5939]

hi ,the amp was put in the same circuit as the meter?

[@ODX171]

Yep

[@toxicblue5939]

and if i put separatly ,it will work the same ?

[@ODX171]

Of course. Why wouldn't it ?

[@toxicblue5939]

thx man (y)

[@ODX171]

Your're WC. GL and HF with your build. Share it with us when you finish it.

[@muhamadnamo4961]

very nice.. i wan to make it.. thanks :-)

[@ODX171]

Thank you. I hope you do make one. Share it with us if you do.

[@green-star1893]

Hi can you please tel me where can I bye the power board

[@ODX171]

Hi George. Power Board ?? Are you referring to the AC adapter?? I got it thru eBay. If your asking about the prototyping board that was used to mount the components to build the circuit --- again there are many many sellers on eBay that can provide you with these.

[@m.a.kaderjibon5709]

super

[@green-star1893]

Hi Thank you for your response you are right am for the AC power board . I try on eBay no luck. I will try again Thank

[@wasanthakumara846]

How to fix led on acrylic sheet

[@ODX171]

If you're asking how I attach the LEDs to the acrylic >>>>> a 5mm hole was drilled and the LED was held in place using hot glue.

[@Dancopymus]

How to do with multiple columns, say eight, as an audio spectrum analyzer? thank you

[@ODX171]

IDK .....you have any ideas ?????

[@Dancopymus]

@@ODX171 No! I'm asking you!

[@ODX171]

@@Dancopymus lol as i said IDK

[@Dancopymus]

@@ODX171 Ok friend; when you know, share it!

[@ODX171]

@@Dancopymus So we are clear Daniel...YOU ARE interested in the audio spectrum analyzer. I am not but I hope you spend the time researching one and sharing what you found. I will not be doing any research into building one...I hope you do....GL friend. I hope you enjoyed my build.

[@isaacfragmatic4651]

can i power 5v volts or lower.?

[@ODX171]

Hi Isaac. I'd try your USB port or even an ac adapter at 5 or less volts. Let us know how you make out. The data sheets for the LM3915 and LM386 indicate they will work with less than 5 V. Always a good place for info on the chips.

[@isaacfragmatic4651]

yes sir .. thank you so much .. im trying to build bluetooth speaker with it and 40000mah power.. i got 76pcs of 18650 batteries laying around so i need to use them instead of nothing.. theoretically, i can make atleast 167mA of banks power at 3.7volts, and ill be using 3 to 5 volts boosters with 1 and 2amps output. ill be adding Battery meter for precision and to spot any degradation of bank batteries, since 167mA isnt allowable on the airport. ill try to make atleast 18mA banks per piece and can be combined and balance at the same time. ill be powering and charging them with BMS and Balancer using laptop adapter for faster charging ...

[@Qubnix]

Is LM3915 N the same as LM3915 IC?

[@ODX171]

Yes

[@Qubnix]

Can you send me link, where did you buy this LEDs ?

[@ODX171]

All electronic parts were purchased thru eBay. Any electronic store near you should be able to help you out.

[@Qubnix]

I wanted link to LEDs because they are good quality and they can light up that plexi.

[@ODX171]

I don't have the specific link for each seller on eBay I buy from but if you want bright LEDs check the spec listed when you buy. I used LEDs with an Intensity spec (mcd) of 5000 or higher whenever possible

[@tientoannguyen4386]

why 2 Power switch ?

[@ODX171]

2nd switch is used to change between bar mode and dot mode as shown in the video.

[@alexandravtushenko5091]

Здравствуете ;подскажите какие нужны детали что бы собрать такую схему

[@ODX171]

Я думал, что детали из описания показывают вам все, что необходимо для сборки, включая список деталей. Что еще тебе нужно ?

[@TheWinGas]

Song?

[@ODX171]

+Wingas Which one ????? Mr Saxobeat - Alexandra Stan or Lambada (Sunset Crew Radio Edit) - Aycan

[@TheWinGas]

+ODX171 Thank you ^-^

[@oyunnoobs6143]

song?

[@jesusguillermoangelesochoa2271]

if you got the song