I'm making a kind of light tower with 2" clear acrylic rod (3x 6'
tall), and putting lights underneath that'll be plugged into my color
organ to react to music.

I'm reading led bulbs are either on or off (true for all?) - obviously
not giving the same visual effect as a regular bulb getting brighter/
darker. So, what might be another option to light up the towers ? Only
thing I can think of is just buying or making color incandescent light
bulbs (red/green/blue), but I think led's would be the way to go if
possible.

On Feb 3, 9:50=A0pm, sku_dave <lastchap...@gmail.com> wrote:
> I'm making a kind of light tower with 2" clear acrylic rod (3x 6'
> tall), and putting lights underneath that'll be plugged into my
color
> organ to react to music.
>
> I'm reading led bulbs are either on or off (true for all?) -
obviously
> not giving the same visual effect as a regular bulb getting
brighter/
> darker. So, what might be another option to light up the towers ?
Only
> thing I can think of is just buying or making color incandescent
light
> bulbs (red/green/blue), but I think led's would be the way to go if
> possible.

LEDs can be controlled quite well by regulating the current which can
be done by PWM or with an analog current source. See page 10 of

http://www.national.com/an/AN/AN-31.pdf

I used a Burr-Brown Operational Transconductance Amplifier to drive an
LED from nearly off to full brilliance at 30 MHz for testing photo
sensors for a telecine (film to video). The linearity ramp was also
excellent.

GG

> LEDs can be controlled quite well by regulating the current which can
> be done by PWM or with an analog current source. See page 10 of
>
> http://www.national.com/an/AN/AN-31.pdf
>
> I used a Burr-Brown Operational Transconductance Amplifier to drive an
> LED from nearly off to full brilliance at 30 MHz for testing photo
> sensors for a telecine (film to video). The linearity ramp was also
> excellent.
>
> GG

Sorry, guess I wasn't clear enough. I'm wondering how these -
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0031317682
will react to lower than 120v

On Feb 3, 10:35=A0pm, sku_dave <lastchap...@gmail.com> wrote:
> > LEDs can be controlled quite well by regulating the current which
can
> > be done by PWM or with an analog current source. See page 10 of
>
> >www.national.com/an/AN/AN-31.pdf
>
> > I used a Burr-Brown Operational Transconductance Amplifier to
drive an
> > LED from nearly off to full brilliance at 30 MHz for testing
photo
> > sensors for a telecine (film to video). The linearity ramp was
also
> > excellent.
>
> > GG
>
> Sorry, guess I wasn't clear enough. I'm wondering how these =A0-
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0031317682
> will react to lower than 120v

Well, it says it works well with dimmers. Isn't that what a color
organ is? An audio driven lamp dimmer? OK you do band separation but
it's still a fancy light dimmer at its core.

GG

> Well, it says it works well with dimmers. Isn't that what a color
> organ is? An audio driven lamp dimmer? OK you do band separation but
> it's still a fancy light dimmer at its core.
>
> GG

Well I guess I totally missed that, good point. Hopefully it works
out ! Thanks.

sku_dave (lastchapter@gmail.com) writes:
> I'm making a kind of light tower with 2" clear acrylic rod (3x 6'
> tall), and putting lights underneath that'll be plugged into my color
> organ to react to music.
>
> I'm reading led bulbs are either on or off (true for all?) - obviously
> not giving the same visual effect as a regular bulb getting brighter/
> darker. So, what might be another option to light up the towers ? Only
> thing I can think of is just buying or making color incandescent light
> bulbs (red/green/blue), but I think led's would be the way to go if
> possible.

You buy color bulbs. A limited selection is available at the local hardware
store, but a dedicated lighting store is likely to have more colors.

Smaller color organs could get by with Christmas tree bulbs, the old
kind that run directly off 120VAC.

If you can't find enough or the right colored bulbs, then you put
regular incadescent spotlights behind color filters (available at
stores that sell theatre lighting).

Michael

In article
<b021dba5-d96b-4066-aa90-38502a6c5ec7@k2g2000hse.googlegroups.com>,
sku_dave <lastchapter@gmail.com> wrote:

> I'm reading led bulbs are either on or off (true for all?) - obviously
> not giving the same visual effect as a regular bulb getting brighter/
> darker.

LED "bulbs" or LEDs? LEDs can certainly be driven at any level between
dark and as bright as they go, simply by providing an appropriate drive
current. LED "bulbs" designed to replace incandescent bulbs may or may
not be dimmable, depending on the circuit used in the "bulb".

--
Cats, coffee, chocolate...vices to live by

sku_dave wrote:
> I'm making a kind of light tower with 2" clear acrylic rod (3x 6'
> tall), and putting lights underneath that'll be plugged into my color
> organ to react to music.
>
> I'm reading led bulbs are either on or off (true for all?) - obviously
> not giving the same visual effect as a regular bulb getting brighter/
> darker. So, what might be another option to light up the towers ? Only
> thing I can think of is just buying or making color incandescent light
> bulbs (red/green/blue), but I think led's would be the way to go if
> possible.
You can PWM (Pulse Width Modulation) the LED's , that'll give you the
luminance effects you are looking for.
Of course, You need a PWM modulator circuit for that.

When you're ready for that stage, just ask.


--
"I'd rather have a bottle in front of me than a frontal lobotomy"


http://webpages.charter.net/jamie_5"