DIMMER AND LED ILLUMINATION SYSTEM

PROBLEM TO BE SOLVED: To provide technology which supplies alternating current converted from direct current and back to alternative current to a first LED and a second LED which are antiparallel connected and also makes dimming control and color matching of the first and the second LEDs possible.SOLUTION: A dimmer includes a direct current generation unit which generates a direct current power supply from alternating current which is received from an alternating current power supply; a first operation unit for manipulating the brightness of illumination light derived by turning a first and a second LEDs on; a second operation unit for manipulating the colors or color temperatures of illumination light derived by turning the first and the second LEDs on; a first control unit which determines the total amount of average currents to be supplied to the first and the second LEDs every prescribed cycle; a second control unit which determines the ratio of average currents to be supplied respectively to the first and the second LEDs every prescribed cycle; and a supply unit which generates alternating current including a positive current to be supplied to the first LED and a negative current to be supplied to the second LED and conforming to the total amount of average currents and the ratio of average currents determined by the first and the second control units and supplies a generated alternating current to an LED illumination device every prescribed cycle.