Point of use lighting controller

A lighting controller circuit for lamps and lamp loads comprising, in combination,

• a. an AC power source;
• b. a full wave bridge rectifier circuit across said AC power source to convert AC line voltage to pulsating DC output voltage;
• c. a switch means across said full wave bridge rectifier circuit comprising a pulse width modulator (PWM) controller integrated circuit comprising an oscillator circuit to produce an output voltage by said PWM to bias the gate of a field effect transistor to induce energy into the primary of a step-down transformer;
• d. a circuit comprising a capacitor and a resistor to set the said oscillator frequency to produce said output voltage by said PWM;
• e. said step-down transformer with a primary winding and two secondary windings, said primary winding receiving energy from said field effect transistor and pulsating DC voltage from rectified AC line voltage of said bridge rectifier circuit, the first secondary winding providing lower voltage to a lamp load, the second secondary winding providing a feedback voltage to said switch means by a feedback voltage regulator circuit;
• f. said field effect transistor turned on by output voltage from said switch means to bias the gate of said field effect transistor;
• g. a voltage regulator circuit regulating the voltage input to said switch means comprising a zener diode, a line voltage dropping resistor, a line voltage filter capacitor;
• h. said feedback voltage regulator circuit from said second secondary winding of said transformer to said switch means through a first center connection divider network of two capacitors and a second center connection divider network of two resistors to provide feedback voltage developed over said feedback circuit to feed a control circuit of said switch means;
• i. said control circuit of said switch means to set the gain of internal circuitry of said switch means comprising said pulse width integrated circuit and operates to set the gain of said internal circuitry;
• j. an internal circuit within said switch means to compare said feedback voltage developed over said feedback circuit with predetermined voltage levels produced by said oscillator circuit of said PMW integrated circuit to set oscillator output frequency to reduce overcurrent product of increased lamp load drawn whereby output DC voltage pulse duration of said PWM integrated circuit to said field effect transistor controls DC voltage output of said transformer to supply a constant output voltage applied to the load;
• k. a voltage sensing circuit comprising a voltage sensing resistor of current drawn through said field effect transistor and primary of said transformer to provide a voltage proportional to current drawn through said field effect transistor and primary of said transformer to cause pulse width modulation of PWM voltage output to gate of said field effect transistor to respond to changes in the lamp load to limit the output current to the lamp load.