Headlamp control circuit
First Claim
1. A headlamp control circuit comprising:
- first and second connecting terminals (101, 102) for outputting low-beam lighting voltages that light first and second luminescent parts (21, 31) to be used as low-beam headlamps, respectively;
third and fourth connecting terminals (103, 104) for outputting high-beam lighting voltages that light third and fourth luminescent parts (22, 32) to be used as high-beam headlamps, respectively;
first and second switch sections (SW1, SW2) for turning on and off supplies of said low-beam lighting voltages to said first and second connecting terminals (101, 102);
a third switch section (SW3) for turning on and off together supplies of said high-beam lighting voltages to said third and fourth connecting terminals (103, 104);
an output voltage detecting section (D1) for detecting an output voltage on said third switch section (SW3);
an indication reception section (105, 106) for accepting a low-beam indication that lights said low-beam headlamps (21, 31) and a high-beam indication that lights said high-beam headlamps (22, 32); and
a control section (120) for turning said third switch section (SW3) to an on-condition in the case where said indication reception section (105, 106) accepts said high-beam indication and for turning said first and second switch sections (SW1, SW2) to an on-condition in the case where said indication reception section accepts said low-beam indication and in the case where said indication reception section accepts said high-beam indication and said output voltage detecting section (D1) detects no high-beam lighting voltage.
1 Assignment
0 Petitions
Accused Products
Abstract
A headlamp control circuit reduces a possibility that all headlamps become lights-out in a two-lamp system headlight, even if a switching element fails under a high-beam condition while the single switching element is driven to light two right and left high-beam filaments. A headlamp control circuit includes switch sections (SW1) and (SW2) for lighting low-beam filaments (21) and (31), a switch section (SW3) for lighting high-beam filaments (22) and (32) together, a diode (D1) for detecting an output voltage on the switch section SW3, and a control section (120) for turning the switch section (SW3) to an on-condition in the case where a high-beam indication is accepted and for turning the switch sections (SW1) and (SW2) to an on-condition in the case where a low-beam indication is accepted and in the case where a high-beam indication is accepted and the diode (D1) detects no high-beam lighting voltage.
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Citations
11 Claims
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1. A headlamp control circuit comprising:
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first and second connecting terminals (101, 102) for outputting low-beam lighting voltages that light first and second luminescent parts (21, 31) to be used as low-beam headlamps, respectively; third and fourth connecting terminals (103, 104) for outputting high-beam lighting voltages that light third and fourth luminescent parts (22, 32) to be used as high-beam headlamps, respectively; first and second switch sections (SW1, SW2) for turning on and off supplies of said low-beam lighting voltages to said first and second connecting terminals (101, 102); a third switch section (SW3) for turning on and off together supplies of said high-beam lighting voltages to said third and fourth connecting terminals (103, 104); an output voltage detecting section (D1) for detecting an output voltage on said third switch section (SW3); an indication reception section (105, 106) for accepting a low-beam indication that lights said low-beam headlamps (21, 31) and a high-beam indication that lights said high-beam headlamps (22, 32); and a control section (120) for turning said third switch section (SW3) to an on-condition in the case where said indication reception section (105, 106) accepts said high-beam indication and for turning said first and second switch sections (SW1, SW2) to an on-condition in the case where said indication reception section accepts said low-beam indication and in the case where said indication reception section accepts said high-beam indication and said output voltage detecting section (D1) detects no high-beam lighting voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A headlamp control circuit comprising:
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first and second connecting terminals for outputting low-beam lighting voltages that light first and second luminescent parts (91, 92) to be used as low-beam headlamps, respectively; third and fourth connecting terminals for outputting high-beam lighting voltages that light third and fourth luminescent parts (93, 94) to be used as high-beam headlamps, respectively; first and second switch sections (SW1, SW2) for turning on and off supplies of said low-beam lighting voltages to said first and second connecting terminals; a third switch section (SW3) for turning on and off together supplies of said high-beam lighting voltages to said third and fourth connecting terminals; an indication reception section for accepting a low-beam indication that lights said low-beam headlamps and a high-beam indication that lights said high-beam headlamps; and a control section for turning said third switch section to an on-condition in the case where said indication reception section accepts said high-beam indication and for turning said first and second switch sections to an on-condition in the case where said indication reception section accepts said low-beam indication and in the case where said indication reception section accepts said high-beam indication. - View Dependent Claims (10, 11)
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Specification