Patent ID: 11910504
Assignee: KOITO MANUFACTURING CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC F  H  B  Y | IPC B  F  H

Claim 0:
1. A light source module comprising: an LED string including four LEDs (light-emitting diodes) connected in series; an LED driver circuit that receives a battery voltage and supplies a drive current stabilized at a target current to the LED string; a bypass circuit that is provided in parallel with a bypassed portion including two adjacent LEDs of the LED string and sinks a bypass current according to the battery voltage, and a break detection circuit that disables the bypass circuit when a break of the bypassed portion is detected, wherein when the battery voltage drops below a predetermined voltage, the bypass circuit sinks the bypass current, the bypass circuit comprises a first voltage comparator and a transistor, the first voltage comparator turning on the transistor based on a comparison of the battery voltage and a first threshold voltage, and the break detection circuit comprises a second voltage comparator that detects the break of the bypass portion based on a comparison of a voltage of the bypass portion and a second threshold voltage.