In the previous part, we have told about an RGB multi-color LED Strips .
At the END of the topic, we have described the RGB Strip theory and It was connected to the power source.
Today’s Tutorial is a logical continue of the topic and we begin with a completely manual power management of the model schematic.
On the already known tutorial schematic (SCH. 1) we’ve inserted three switches. With their help, we can produce 2 3 = 8 combinations.
Starting With Blank state – Three Controlling Switches are OFF, 6 different colors, and Creating White color, using both three colors R-G-B. See the Table 1 for more details.
- SW-x = Closed = 1 ( High Logical Level ) ,
- SW-x = Opened = 0 ( Low Logical Level ).
The “Binary” explanation of the color mixing.
|Color 000 / Black||0||0||0|
|Color 001 / Red||0||0||1|
|Color 010 / Green||0||1||0|
|Color 011 / Yellow||0||1||1|
|Color 100 / Blue||1||0||0|
|Color 101 / Magenta||1||0||1|
|Color 110 / Cyan||1||1||0|
|Color 111 / White||1||1||1|
TABLE. 1 a Color Selection by State of [SW-x] Switches
PIC. 1 Typical Example of Additive Color Mixing.
SCH. 1 Tutorial: The Schematic of knowledge
With manual control, as you see, we can isolate only 7 Different color’s ( counting and White Color).
That limitation tilts the scales in the other direction.
Into the practice, the necessary of a larger amount of different colors brings the need from Electronic Controllers.
1.) Basics of Electronic RGB Controllers
Is common case the electronic Controller is the device with one or more inputs and single or a multiple (different Channels) outputs. The First Input is Power Supply jack. Here are used a low number of AWG wires to minimize power losses.
Here is the place to say – The second Input is optional and It is a wireless – RF remote control ( generally – remote type wafer).
The electronic controller’s remote is HID (Human Interface Device) which allows quickly and simple to adjust an intensity of each color.
Into the program code of a controller can be inserted many programs to randomly or periodically, or “fade effect” changing the color of emitting light.
These Visual effects are very special and favorite to specialists of waterfall or Water shower illuminating.
The Outputs can be for Single RGB LED Strip or for multiple RGB LED Strips.
We will try to explain with simple words a principle of the RGB electronic controller.
Let return a little bit above into the text of tutorial and focus on ( SCH. 1 ).
Imagine, the mechanical switches are replaced with electronic switches. In common cases, the switching devices are Bipolar or MOSFET- Transistors. That supposition, make things much more flexible. (See the SCH. 2)
SCH. 2 Electronic switch basics – Used Semiconductor is bipolar N-P-N transistor
a Little variation of Vin (UEB) > 0.7V , creates Full-Amplitude Voltage and Inverted Output
In the beginning of today part’s context, we USE inverted Logic of meaning.
” SW-x = Closed = 1 ( High Logical Level ) ,
SW-x = Opened = 0 ( Low Logical Level ). “
Closed Switch – High Logical Level . This is just for easily implementing inverting type of the electronic switch .
Example: Using Management Signals with High Level to Base/Gate of Electronic Switch of RED Segment: Equal to Low Level on Output of the electronic Switch – (After imaginary replacement of mechanical Switches with electronically) – RED Color LED is Flash.
The controlling MCU (MicroController Unit) via electronic switches can easily manipulate ( USING PWM Technique) the RMS (Root Mean Square) Voltage on each R-G-B outputs of Channel 1 to Channel n. – (To remember PWM Topic or just for more information, see again the TimeDiagram from previous parts of this Tutorial )
Time Diagram 1
Time Diagram 2
PIC. 2 Typical Member of RGB controllers
PIC. 3 RGB Controller BC-350-6A
VIDEO 1. LED Strip Lights – Controller Effect Example
VIDEO 2. Example: DMX PWM 36CH Decoder in Action with the Analog RGB LED Strip
VIDEO 3. Example: 30-Channel DMX Controller Under 40-USD
Don’t Stop To Create and to Invent, dear Explorers!