Lighting circuit for light emitting diode

Abstract

Abstract PURPOSE:To decrease a power loss and also to prevent a current fluctuation according to lighting number by a method wherein a plural light emitting diode is connected in series and driven by a constant current circuit, and the diodes are made flashing by a switch connected in parallel therewith. CONSTITUTION:A plural light emitting diode 4-7 is connected in series, and switches 8-10 are connected between anode and cathode of the diodes 4-7. A constant current circuit comprising a transistor Tr14, a constant voltage diode 13 and a resistor 12 is connected to the cathode side of the diode 7 connected in series, a power supply 15 is connected to the constant current circuit through a resistor 11, a junction of the resistor 11 and the power supply 15 is connected to the anode side of the diode 4, and thus the diodes 4-7 are diriven by the constant current circuit. Then, the diodes 4-7 are made flashing by the switches 8-10, thereby preventing a current fluctuation according to lighting number and also decreasing a power loss.

Inventors

• 👤 Takao Sato
• 👤 Akimasa Yamazaki

Bibliographic Details