10 LEDs lit it up acording to potentiometer variation

[adrianbodor]

Hy,

I want to build a circuit based on 10 leds & pot (anyway this is the ideea only, other components is needed also)

My question is how can I make all those leds to light up acording to the potentiometer variation.

When I have the pot set to minimum i want all leds down,when is set to middle only first 5 leds to be lit & when all leds are lit pot is set to maximum

Anyway i think u get the idea. Anyone knows such a circuit, ICs or links to all this?

Thx Adrian,

 

[AudioFreak]

What other requirements do you have? supply voltage/s etc?

 

[Nordic]

Well I suppose you will start with a dual gang pot, one half to be used as the pot for your regular circuit and one to controll the LEDs, I suppose a 3 gang one would allow you even stereo control.

You will also need a little circuit to measure voltage and then light the LEDS, I think there are LED VU meter circuits that you could slide right in there.

 

[adrianbodor]

Yes i was thinking to use a dual pot, one for my circuit & the other one for the leds but it is only an ideea.

I don't know what IC to use that's why I need some schematic for this.

 

[karma]

i have a not so old dvd player with just that setup.if you want i can take some pics. im sure this ones all digital.

nordics 3 gang pot allso would work for this purpose. and cheaper

 

[adrianbodor]

Anything that would help me, pictures, circuits, links, anything
Thx in advance

Adrian,

 

[karma]

well theres not much to this one all of it is surface mount.

but here some pics anyway

 

[karma]

pcb lcds

.

 

[karma]

back

cheers

 

[Mephistopheles]

Have a look at the LM3916 datasheet

http://www.national.com/ds/LM/LM3916.pdf

I think it will do what you want.
There's a logarithmic one too if that floats ya boat.

 

[thespeakerguy]

I believe you are looking for thermometer code, in that at 90% volume, 9 leds are lit, correct?

Use a 3 quad comparators such as the LMX339 devices. Set up a resistor string and create a flash converter, which outputs thermometer code.

Alternativel, NSC used to make a device which was self contained, but I am not sure if it is still available.

 

[adrianbodor]

That is corect.Could u point to some website where I can find some schematic or ideeas for this.

THX

 

[dnsey]

Why not keep it simple?
Build a switched attenuator, which will sound better than most pots, with an additional bank for the LEDs.

 

[Nordic]

Agree with the last post, once again, it will have to be a 3 gang jobbie, so expect to fork out a few bucks... preferably get a make before break one. But surely we have to expand it then to prevent the LEDs going dimmer as more switch on.

 

[dnsey]

But surely we have to expand it then to prevent the LEDs going dimmer as more switch on.

No, the LEDs (with limiting resistors) would be run in parallel.
An extra wafer on the switch will be much cheaper and easier than sourcing a 3-gang pot.

 

[johnnyx]

You could run the LEDs in series fed by a constant current source, short the LEDs that you don't want lit to ground. The LM339 comparator can do this. You need enough voltage for all the LEDs plus a bit for the current source to operate. I've seen this done in commercial equipment.

 

[jleaman]

Why not keep it simple?
Build a switched attenuator, which will sound better than most pots, with an additional bank for the LEDs.

This is a nice easy Way..I'm folowing this thread to see where it ends up .. I'm intersted in this would look nice sitting in the dark and being able to see where the volume pot is

 

[Nordic]

You could compliment it by adding a similar LED VU meter around the balance control... would look awesome... say 5 LEDs makeing up each of the 2 halves of the circle.

 

[davesaudio]

interesting how the same question propogates around the various forums...
so what was wrong with the bar graph driver which nicely manages the individual led currents?