ÇevirisiThis circuit is essentially the same as the smaller RGB driver using the 5mm LEDs elsewhere on this website except that this version uses high power MOSFETs capable of sinking 3 amps on each channel without heatsinks (at 5amps the MOSFETs will run hot)
The input power to the board must be regulated DC and be capable of suppling the power requirements of the output load.
The circuit will operate from a supply voltage in the range 9 to 18 volts. This voltage range is dictated by the input requirements of the 78L05 voltage regulator and capacitors C3/4.
Switch S2 is not used with the firmware on this website and you do not need to fit it. I've incorporated it the PCB design because I've written some customized versions of the code that did require two switches.
How much power can it handle?
During testing I connected the controller to some 50W / 12Volt halogen downlight bulbs, one on each channel then ran them at 100% PWM duty cycle.
Based on these measurements and the specification of the MOSFETs and PCB connectors, the controller should comfortably handle 3 amps per channel. While the individual MOSFETs could handle more current, the PCB screw terminal connectors are rated at 16 amps and since there is only a single Ground connection to the board, total load for the three RGB channels should not exceed this.
Ambient temperature during test 22oC MOSFET temperature after 5mins (measured on metal tab) 52oC Current (sink per channel) 4.4A Voltage drop across MOSFET Source-Drain terminal (measured) 20mV
Description | Filename | Download link |
Version 2 Source code | rgbsa-inet.zip V2.0.2 09/06/2007 | download |
V2 HEX file ready to program for 12F629/675 | rgbsa-int675.HEX V2.0.2 09/06/2007 | download |
V2 HEX file ready to program for 12F683 | rgbsa-int683.HEX V2.0.2 09/06/2007 | download |
Version 3 Source code | genRGBsa.zip V3.0.3 28/09/2008 | download |
V3 HEX file ready to program for 12F629/675 | rgbsa303_629.HEX V3.0.3 28/09/2008 | download checksum 97E0 |