Light control circuit

• US 4,739,224 A
• Filed: 03/20/1986
• Issued: 04/19/1988
• Est. Priority Date: 03/20/1986
• Status: Expired due to Fees

• Current Assignee: Prince (Wellman Holdings, Inc.)
• Original Assignee: Prince (Wellman Holdings, Inc.)
• Inventors: Geerlings, Steven L.
• Primary Examiner(s): Moore, David K.
• Assistant Examiner(s): Razavi, Michael
• Application Number:
  US06/841,560
• Time in Patent Office: 761 Days
• Field of Search: 315/84, 315/83, 315/82, 315/191, 315/76, 315/77, 307/10 LS, 307/10 R
• US Class Current: 315/84
• CPC Class Codes: B60Q 3/80 Circuits; Control arrangements for dashboards B60Q3/16; for mass transit vehicles B60Q3/47

Abstract

A light control circuit includes a latching circuit actuated by a manually actuated switch to, in turn, activate a solid-state switch coupled to supply power to one or more lamps. The latching circuit is reset by a diode coupled to the door actuated switches such that in the event the interior lamp or lamps are manually operated and a door subsequently opened, the lamps will be extinguished upon the closing of the door regardless of the prior manual activation of the lamps.

Claims

1. An interior light control circuit for a vehicle comprising:

at least one interior vehicle light;

first circuit means coupled to said vehicle interior light and including first manually actuated switch means for providing current for illuminating said vehicle interior light comprises a latching circuit responsive to the momentary actuation of said first switch means for changing states and a solid-state switch coupled to said light and a power source and responsive to an output of said latching circuit to provide a current path through said light;

door actuated switch means coupled to said vehicle interior light for providing current for illuminating said light when an associated door is opened;

second circuit means includes means for resetting said latching circuit comprising an unidirectional conductive device coupled between said latching circuit and said door actuated switch means for detecting when said light is actuated by said first switch means and responsive to the subsequent actuation of said door actuated switch means by the opening of a door to provide a signal applied to said first circuit means to cause said first circuit means to terminate current to said light to turn said light off when said door actuated switch is subsequently actuated by the closure of said door even though said manually actuated switch has been actuated to illuminate said vehicle interior light.

2. The control circuit as defined in claim 1 wherein said unidirectional conductive device comprises a diode having an anode coupled to said latching circuit and a cathode coupled to said door actuated switch.

3. An electrical control circuit for a vehicle interior light comprising:

a source of electrical power;

a lamp for providing illumination to the vehicle interior;

a solid-state switch for selectively coupling said lamp to said source;

at least one switch coupled to said lamp and actuated by a vehicle door for coupling said lamp to said source when the door is opened;

a manually actuated switch for the manual activation of said lamp;

a latching circuit including a reset terminal, said latching circuit coupled to said manually actuated switch and to said solid-state switch for controlling the conductive state of said solid-state switch in response to the operation of said manually actuated switch; and

a unidirectional conductive device coupled to said reset terminal of said latching circuit to said door actuated switch such that said latching circuit will be reset to turn said solid-state switch off in the event it is in a conductive state and said door operated switch is closed by the momentary opening and subsequent closing of the vehicle door.

4. The circuit as defined in claim 3 wherein said unidirectional conductive device is a diode.

5. The circuit as defined in claim 4 wherein said diode has an anode coupled to said reset terminal of said latching circuit and a cathode coupled to said door actuated switch.

6. The circuit as defined in claim 5 wherein a plurality of interior lamps are provided and each includes an associated latching circuit and manual switch means and wherein a diode is coupled from the reset terminal of each latching circuit to said door actuated switch.