Where to find NSM3914 (integrated LED and LM3914 driver)

[dinofx]

Does anyone know where to find this integrated part?

 

[audioguru]

These modules were made many years ago, I stll have four with the LM3915 logarithmic IC. They have the dimmest LEDs ever made.
I have a pic and a terminals layout. Here is the pic:

 

[audioguru]

Here is the terminals layout:

 

[zevon8]

If I remember right, Radio Shack used to sell those.. I think it was there I got one in the mid 1970's. I agree, the LED's were terrible. Better to just do the circuit yourself with one of the IC ( LM3915 , LM3914, LM3916 )and separate LED's.

audioguru: is that a Forrest Mimms "Engineer Note" ?

 

[audioguru]

audioguru: is that a Forrest Mimms "Engineer Note" ?

It looks like that book that RadioShack also sold. I might have the book on my hard drive but I found the NSM info recently with a search on Google, one page has a coffee stain on it.
I agree that an ordinary 18 pin IC and a 10-LED lightstrip is easy like in my project (I used two LEDs in series to make it look like stereo):

 

[dinofx]

audioguru: is that a Forrest Mimms "Engineer Note" ?

Hah! That's the book series in which I learned about this part! Everything is hand-drawn, but my books don't have a grid in the background.

Guru, the part looks pretty dated now that I see it up close (and in color). Too bad there's not a modern-day equivalent.

 

[audioguru]

Hi Dino,
The pins on the IC have all 10 outputs in sequence so it is easy to connect to an array of LEDs.

 

[justDIY]

man, as huge as that ancient part is - you could do a lot better with surface mount parts, or even standard parts with a stacked / layered approach

 

[audioguru]

man, as huge as that ancient part is - you could do a lot better with surface mount parts

They are available in a surface-mount package, but its heat dissipation is too low for most applications. Its 10 output transistors are current regulators that eliminate the need for 10 current-limiting resistors for the LEDs. With the surface-mount package you could operate the output transistors saturated for them to be cool, then add 10 regular resistors or a 20 pin resistors package.

 

[Xstatic]

https://www.ebay.com/sch/i.html?_fr...TRC0.H0.Xnsm+3915.TRS0&_nkw=nsm+3915&_sacat=0 ;-)

 

[chemelec]

Sorry Don't have any 3914's but do have these NSM3915's
FREE if you want them, Just Pay for Shipping Cost.

 

[bountyhunter]

Funny, the VU meter I built uses a LM3914. I didn't realize they were antiques now.

TI shows them as current.

https://www.ti.com/lit/ds/symlink/lm3914.pdf

Scamazon sells them:

https://www.amazon.com/s/?ie=UTF8&k...qmt=e&hvbmt=be&hvdev=c&ref=pd_sl_2omzrabs3v_e

 

[chemelec]

The LM3914, 15 and 16 are Still Current.
The NSM3914, 15 and 16 were Discontinued many Years Ago.

But Why did you make a VU METER with an LM3914?
The LM3914 is a Linear Scale.

You should have used an LM3915. (3 dB Scale)
Or the LM3916, which is the VU Version. (-23 to +3 dB)

 

[bountyhunter]

The LM3914, 15 and 16 are Still Current.
The NSM3914, 15 and 16 were Discontinued many Years Ago.

But Why did you make a VU METER with an LM3914?
The LM3914 is a Linear Scale.

You should have used an LM3915. (3 dB Scale)
Or the LM3916, which is the VU Version. (-23 to +3 dB)

The 3914 is better because I wanted to display the range of about -14 to +6 dB in ten steps. It gives me much better resolution between 0dB and 6 dB.

 

[chemelec]

Not sure why you would need such precision in that range?

And Only if you can actually Convert the Specific LED Displays to the specific dB.
dB is Not Linear, (1,2,3,4,5........) it is a Doubling of Voltages. (1,2,4,8,16.......)

 

[bountyhunter]

Not sure why you would need such precision in that range?

Simple: to be able to accurately set loudness and also detect signal clipping. I don't care about signals below -10dB or beyond +6 when my objective is to accurately set recording level so all tracks sound the same loudness.

And Only if you can actually Convert the Specific LED Displays to the specific dB.
dB is Not Linear, (1,2,3,4,5........) it is a Doubling of Voltages. (1,2,4,8,16.......)

I didn't have to convert anything, just adjust the signal level. Signal step levels do not double on each step, they increase by 0.125V in my design. DB levels are listed next to the part. The design would be useless if it had 3dB steps as there would be no usable accuracy.

 

[bountyhunter]

This picture shows the scale.

 

[schmitt trigger]

Bountyhunter;
I see what you are doing...instead of having a single "peak led" you have an array that warns you when the signal level is getting close to that peak.
Very Nice!

Also, a very good looking "retro" project.

 

[chemelec]

Using some Comparators, You could get a Better Scaling on the LED's.