| 摘要 |
PURPOSE: To control electric power consumed by a DC-AC converter to exclusively depend on an electric current flowing through a load circuit by forming a part of the load circuit out of an electric current sensor, and joining a control circuit to an end part of the load circuit. CONSTITUTION: A control circuit C to control electric power consumed by a lamp LA is joined to an electric current sensor SE and an end part of a load circuit B. When terminals 1 and 2 of a circuit A are connected to an electrode of a DC voltage source, a driving signal alternately and electrically continues switching elements S1 and S2 with each other in a frequency (f), and an electric current whose polarity changes in a repetitive frequency (f) is made to flow in the load circuit B. At this time, a first signal being a measure to an average value of electric power consumed by the lamp LA is generated in a circuit D. A circuit E sends a control signal to a driving circuit F on the basis of this signal, and adjusts it by a method that the average value of the electric power consumed by the lamp LA becomes almost equal to a desired value. |
