System and method for controlling an output illumination level of a lighting system

A method of controlling a brightness level of an LED comprising the steps of:

• supplying power to an LED;
• the LED being in series with a transistor and a resistor;
• connecting an output of an operational amplifier to the transistor;
• supplying a first voltage from a digital potentiometer to a first input of the operational amplifier;
• activating the transistor based on a voltage output from the operational amplifier;
• varying a current through the LED when the transistor is activated;
• supplying a second voltage developed across the resistor to a second input of the operational amplifier to provide a stabilized output of the operational amplifier;
• and
• outputting a voltage from a second operational amplifier and a voltage from a negative side of the resistor to the digital potentiometer to swamp the error of the digital potentiometer;
• wherein the varying of the current through the LED changes the brightness level of the LED.

A method of controlling a brightness level of an LED comprising the steps of:

• supplying power to an LED;
• the LED being in series with a field effect transistor and a resistor;
• supplying a voltage from a digital potentiometer to a first operational amplifier;
• activating the field effect transistor based on a voltage from the first operational amplifier;
• varying a voltage across the resistor when the field effect transistor is activated;
• wherein the varying of the voltage across the resistor changes the brightness level of the LED and;
• outputting a voltage from a second operational amplifier and a voltage from a negative side of the resistor to the digital potentiometer to swamp the error of the digital potentiometer.

A system for controlling an output illumination level of a lighting system comprising:

• a voltage source;
• an illumination device coupled to said voltage source;
• a voltage converter coupled to said illumination device;
• a load coupled to said voltage converter;
• a controller coupled to said voltage source and a switch;
• said controller providing a variable voltage to said switch;
• said load connected to said voltage converter such that a voltage developed across said load is fed to said voltage converter;
• and
• wherein the output illumination level of said illumination device varies according to the variable current passing through said illumination device, wherein said controller is a microcontroller and further comprising a digital potentiometer coupled to said microcontroller.

A system for controlling a brightness level of a Light Emitting Diode comprising:

• a Light Emitting Diode (LED);
• said LED connected in series with a field effect transistor (FET) and a resistor;
• a digital potentiometer;
• said digital potentiometer supplying a variable output voltage to an operational amplifier;
• said operational amplifier connected to said FET to activate said FET;
• a power supply connected to said LED;
• wherein said activation of said FET by said operational amplifier varies a voltage across said resistor adjusting the brightness level of said LED;
• and
• wherein said digital potentiometer is connected to a negative side of said resistor and to an output of a second operational amplifier to swamp an error of said digital potentiometer.