Dimmer passing device for headlamp of vehicle

• US 4,683,403 A
• Filed: 07/17/1986
• Issued: 07/28/1987
• Est. Priority Date: 07/24/1985
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho, Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: Ikeda, Toshiki, Iwamoto, Tadashi, Arakawa, Kaneyasu, Hattori, Masaichi, Hanaki, Akira, Yukitomo, Kazuo, Kihira, Koichi
• Primary Examiner(s): Dixon, Harold
• Application Number:
  US06/886,404
• Time in Patent Office: 376 Days
• Field of Search: 315/82, 315/83, 307/10 LS
• US Class Current: 315/83
• CPC Class Codes: B60Q 1/1415 Dimming circuits

Abstract

There is provided a dimmer passing device for a headlamp of a vehicle having a light switch which drives a light relay when it is on, a momentary control switch which activates the light relay when it is on, a latch circuit which alternately turns on and off an internal switching element in response to the on state of the momentary control switch, and a dimmer relay which causes the light relay to energize a low beam of the headlamp when the internal switching element is turned off and which causes the light relay to energize a high beam of the headlamp when the internal switching element is turned on.

Claims

1. A dimmer passing device for a headlamp of a vehicle comprising:

a light switch operable selectively to an on and off state;

a momentary control switch operable selectively to an on and off state;

a light relay operative when driven for energizing one of a low beam portion and a high beam portion of said headlamp;

first circuit means connecting said light relay to said light switch for activating said light relay in response to the on state of said light switch;

second circuit means connecting said light relay to said momentary control switch for activating said light relay in response to the on state of said momentary control switch;

latch circuit means including an internal switching element operative to alternately turn on and off said internal switching element in response to the on state of said momentary control switch;

a dimmer relay operative to a first position for causing said light relay to energize said low beam portion and operative to a second position for causing said light relay to energize said high beam portion; and

third circuit means for operating said dimmer relay to said second position at times when said internal switching element is in the on state, and for operating said light relay to energize said low beam portion at times when said dimmer relay is operated to said first position and said internal switching element is in the off state.

2. A dimmer passing device for a headlamp of a vehicle as claimed in claim 1, wherein said latch circuit is connected to restore said internal switching element from an on state to an off state at times when said light relay is de-energized.

3. A dimmer passing device for a vehicle comprising:

a headlamp having a first filament for a high beam of light and second filament for a low beam of light;

a relay operative when driven for energizing one of said first filament and said second filament;

switch means for driving said relay;

momentary control switch means for driving said relay only at times when said momentary control switch means is turned on;

a latch circuit having an internal switching element alternately turning on and off at times when said momentary control switch means is turned on; and

dimmer relay means for actuating said first filament for said high-beam of light when said internal switching element is turned on and while said relay is on, and for actuating said second filament for said low beam of light when said internal switching element is turned off.

4. A dimmer passing device as claimed in claim 3, wherein said internal switching element of said latch circuit is turned off when said relay is de-energized.