Complete "April 1 2006", Origional N-Mos Version.
LATEST UPDATE: Mar 4, 2009
UPDATE: Dec 24 2006, My NEW P-Mos Version allows for "Common Grounded Lamps".
LATEST UPDATE Mar 4, 2009
As Requested by MANY of my readers, here are Two, Good 3 channel color organs,
for use in a Vehicle.
WARNING: Using a Color Organ in your Vehicle, Especially While Driving is:
"Probably Illegal and Definately Distracting".
So If you do this, It is at your OWN RISK.
Back in the 1970's these were popular for use in homes and the colored bulbs
were typically place in a box with a sheet of "rippled/bubbled" Plastic in
front to break up the light patterns. Some units gave very impressive light
patterns.
Using an LM324, this circuit has 3 active filters for the Low, Medium
and High frequencies.
** This allows for a Much better seperation beween the various frequency
ranges than the simple Passive Filters as used on many Color Organs.
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Setting it up:
Set the Master Level to about a 1/4 on position.
Trimpots are initally used to set the 3 filters to equal ranges so the lights
all flash in about equil amounts of time.
The Master control, is usually a regular potentiometer, is than used
to set for various volume levels.
(I just used a trimpot on my proto for testing purposes.)
As Shown on the Schematic, Proper Rated FUSES are Highly Recommended.
Except for the On-Board fuse that protects the IC Circuit,
The ones protecting the Mosfets should be "Automotive Types",
with a voltage rating of 32 Volts.
"T1" is for Isolation and signal boost. It can be almost any small audio
transformer,
used in reverse.
The one stated here is reasonably priced and fits the board nicely.
"T1" is Essential to "Isolate" the audio output from ground on Non-Grounded
Audio Systems.
"RX", As Shown on the Circuit Board is a series resistor to the 8 Ohm
Input.
It may be Necessary to use an appropriate value resistor to limit the current
to T1 if this is connected to a power amp.
Even Better is to use a #1819 or 1821 (28 Volt) Minature light bulb
in place of this resistor. It will better compensate for Excessive current flow.
I can supply the 1819 Bulb, If Wanted.
In all my tests I went directly into T1, but I was running this circuit from
a Headphone output, Very low power.
I would suggest a value, somewhere between 20 to 500 ohms, depending on your
Amplifiers power.
Heatsinks May be required on the Mosfets, Depending on you load Currents.
For the N-Mosfet Version, The RFP50N06 has a good rating. With a Proper Heatsink,
it is Probably suitable for loads up to 30 amps.
The Two transistors that I use in front of the N-Mosfets, Increases the Drive
voltage to the Mosfets so they should either be full on of full off, thus
giving best power efficiency.
Heatsinks May be required on these Mosfets also, Depending on you load Currents.
For the P-Mosfet Version, The IRF4905 has a good rating. With a Proper Heatsink,
it is Probably suitable for loads up to 30 amps or so.
The single transistors that I use in front of the P-Mosfets, Increases the
Drive voltage to the Mosfets so they should either be full on of full off,
thus giving best power efficiency.
The Loads:
Although I Prefer Standard Filament Bulbs, It Can be Many LED's with there
appropriate resistors or a considerable number of 12 Volt Incandescent Bulbs.
Filament Type Bulbs give a Much Better Effect than LED's, because they give
a better Brightness Variation.
The Tiny Series String Christmas Tree Bulbs Work Excellent.
Typically they come in Various Colours, they are Cheap and are between 2 to 4
volts each. So you can Series, 3 to 6 of them, Than Parallel these to use Many
Bulbs on each channel.
Other Devices such as the 12 volt Colored Neon lights may also work.
I Don't have them to give it a try.
P-Mosfet Verses N-Mosfet:
While the P-Mosfet Design can drive a Grounded load,
"It is Not as Efficient or Relialable as the N-Mosfet Version".
SO, If you Don't need to drive Common Grounded Bulbs,
"DON'T Build this P-Mosfet circuit".
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