LED OPERATION DEVICE AND HEAD LAMP LED OPERATION DEVICE

摘要

A switching transistor (7) is turned ON to supply a current to a choke coil (L1) from a DC power source (8).  When the current reaches a predetermined value, the switching transistor (7) is turned OFF to generate a pulse-shaped current, which is supplied to turn ON an LED series circuit.  The pulse-shaped current generation cycle is determined in accordance with a value of the average current flowing in the LED series circuit by using an oscillator (VCO) (4).  Each of the pulse-shaped current value and the average current value is controlled as is required.