Circuit continuity and function monitor

• US 6,967,445 B1
• Filed: 04/19/2004
• Issued: 11/22/2005
• Est. Priority Date: 04/19/2004
• Status: Expired due to Fees

• Current Assignee: Dan J. Jewell, Judith D. Jewell
• Original Assignee: Dan J. Jewell, Judith D. Jewell
• Inventors: Jewell, Dan J., Jewell, Judith D.
• Primary Examiner(s): TRAN, THUY V
• Application Number:
  US10/826,068
• Time in Patent Office: 582 Days
• Field of Search: B60/L00.1/14, G01/R03.1/02, H01/H03.1/02, H01/J00.1/60, 315 76- 77, 315/129, 315/131, 315/133, 307/10.1, 307/10.6, 307/10.8, 307/139, 307/142, 324/418, 324555-556
• US Class Current: 315/129
• CPC Class Codes: G01R 31/44 Testing lamps
• CPC Class Codes: H01K 3/305 Testing of incandescent lamps

Abstract

A circuit to monitor electrical continuity through a light bulb when the light bulb is switched off, and to monitor proper functioning of the light bulb when the bulb is switched on. The circuit comprises a LED, a relay and a latching circuit portion, the latching circuit portion configured to remain latched thereby applying power to the bulb and the relay only when the bulb is switched on and lit, and the relay having a pair of normally closed contacts connected to provide an alternative path of minimal resistance to ground for low voltage applied to an incoming side of the LED, and the relay also having a pair of normally open contacts which when closed allow voltage to be applied to the outgoing side of the LED, thereby resulting in the LED lighting when and only when, the light bulb is broken. Most preferably the latching portion of the circuit comprises a silicone controlled rectifier having a trigger circuit portion configured to pulse the gate when a switched light power control line is energized. The switched light power control line is connected to the anode and a coil of the relay, and the cathode is connected to one of the normally closed contacts of the relay and to the light bulb.

Claims

1. A method of monitoring the operability of a light bulb, both while lit and/or unlit, comprising the steps of:

providing a circuit containing a LED, a relay and a latching circuit portion, said latching circuit portion configured to remain latched thereby applying power to the bulb and the relay only when the bulb is switched on and lit, and said relay having a pair of contacts connected to provide an alternative path of minimal resistance to ground for low voltage applied to an incoming side of the LED, and said relay also having an additional pair of contacts which when closed allow voltage to be applied to an outgoing side of the LED, thereby resulting in the LED lighting when and only when the light bulb is broken;

electrically connecting to the circuit, the light bulb to be monitored, ignition power, a switched light power control line, and ground.

2. A method as in claim 1 wherein the contacts of the relay which are connected to provide an alternative path of minimal resistance to ground for low voltage applied to the incoming side of the LED, are normally closed;

and wherein the contacts of the relay which are connected which when closed allow voltage to be applied to the outgoing side of the LED, are normally open.

3. A method as in claim 2 wherein the latching portion of the circuit comprises a silicone controlled rectifier having a gate, an anode and a cathode, as well as a trigger circuit portion configured to pulse the gate when the switched light power control line is energized, and wherein the switched light power control line is connected to the anode and a coil of the relay, and wherein the cathode is connected to one of the normally closed contacts of the relay and to the light bulb.

4. A method as in claim 3 wherein a resistor is provided between the outgoing side of the LED and the ground to substantially restrict power from flowing through the LED when an alternative path to the ground is available through a filament of the light bulb.

5. A circuit to monitor the operability of a light bulb, both while lit and unlit, comprising:

a LED, a relay and a latching circuit portion, said latching circuit portion configured to remain latched thereby applying power to the bulb and the relay only when the bulb is switched on and lit, and said relay having a pair of contacts connected to provide an alternative path of minimal resistance to ground for low voltage applied to an incoming side of the LED, and said relay also having an additional pair of contacts which when closed allow voltage to be applied to an outgoing side of the LED, thereby resulting in the LED lighting when and only when the light bulb is broken.

6. A circuit as in claim 5 wherein the contacts of the relay which are connected to provide the alternative path of minimal resistance to the ground for low voltage applied to the incoming side of the LED, are normally closed;

and wherein the relay contacts which are connected which when closed allow voltage to be applied to the outgoing side of the LED, are normally open.

7. A circuit as in claim 6 wherein the latching portion of the circuit comprises a silicone controlled rectifier having a gate, an anode and a cathode, as well as a trigger circuit portion configured to pulse the gate when a switched light power control line is energized, and wherein the switched light power control line is connected to the anode and a coil of the relay, and wherein the cathode is connected to one of the normally closed contacts of the relay and to the light bulb.

8. A circuit as in claim 7 wherein a resistor is provided between the outgoing side of the LED and the ground to substantially restrict power from flowing through the LED when an alternative path to the ground is available through a filament of the light bulb.

9. A method of monitoring the operability of multiple light bulbs, both while lit and/or unlit, comprising the steps of:

providing LEDs arranged in a display panel having a front side portion representing a layout of the light bulbs, said layout having LEDs appropriately positioned thereon so as to correspond to the light bulbs in the layout;

providing multiple circuits each circuit provided to monitor the operation of a particular one of the light bulbs, each circuit containing a relay and a latching circuit portion, said latching circuit portion configured to remain latched thereby applying power to the particular one of the bulbs and the circuit relay only when the particular one of the light bulbs is switched on and lit, and said relay having a pair of contacts connected to provide an alternative path of minimal resistance to ground for low voltage applied to an incoming side of a LED corresponding to the particular one of the bulbs, and said relay also having an additional pair of contacts which when closed allow voltage to be applied to an outgoing side of the LED corresponding to the particular one of the bulbs, thereby resulting in the LED corresponding to the particular one of the bulbs lighting when and only when particular one of the light bulb is broken;

electrically connecting to the circuit, the light bulbs to be monitored, unswitched power, a switched light power control line, and ground.

10. A method as in claim 9 wherein the multiple light bulbs monitored are light bulbs on a vehicle, and wherein the LEDs are arranged in the display panel displaying a shape of the vehicle and having the LEDs positioned thereon to correspond to the light bulbs on the vehicle.

11. A method as in claim 10 wherein the vehicle display panel comprises a chip.

12. A method as in claim 11 wherein said chip comprises an audio alarm configured to sound when the LED that corresponds to the particular one of the light bulbs is lit.