Voltage detector for series light circuit

• US 6,518,707 B2
• Filed: 06/22/2001
• Issued: 02/11/2003
• Est. Priority Date: 06/22/2001
• Status: Expired due to Fees

• Current Assignee: DG Partnership An Illinois General Partnership
• Original Assignee: DG Partnership An Illinois General Partnership
• Inventors: Gershen, Bernard J., DeCosmo, John
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): VO, TUYET THI
• Application Number:
  US09/893,020
• Publication Number:
  US 20020195945A1
• Time in Patent Office: 599 Days
• Field of Search: 315/129, 315/130, 315/132, 315/133, 315/185.R, 315/192, 315/185.S, 315/312, 315/324, 362/800, 362/806, 362/812
• US Class Current: 315/129
• CPC Class Codes: H05B 39/105 with a spare lamp in the circuit, and a possibility of shunting a failed lamp lamp changing devices H01R33/00, H01R43/00; incandescent lamps with a reserve body H01K

Abstract

A string of miniature holiday lamps connected in a series circuit with each lamp having an indicating device connected in parallel to its respective lamp. The indicating device is operated in response to the non functioning of the lamp with which it is connected in parallel. When the lamp fails, the full line voltage of the series circuit passes through the indicating device causing it to activate, signaling the non functioning lamp. The signaling device can be a resistor associated with a thermochromic paint that changes color when activated by the heat from the resistor, a sound alarm, an odor activated device or an electroluminescent light. In another embodiment the signaling device can be used to indicate a circuit having a resistive load is energized.

Claims

1. A method for indicating a non functioning lamp or socket in a string of miniature electrical lights comprising the steps of:

(a) providing a plurality of miniature sockets, each socket having disposed therein a miniature lamp, the socket and its respective lamp connected in a series circuit;

(b) providing a plurality of resistors with thermochromic paint applied over the resistor, one resistor for each of the miniature lamps;

(c) electrically connecting one of the resistors in parallel with each one of the miniature lamps in the series circuit;

(d) automatically providing an electrical signal to the resistor connected in parallel with its respective miniature lamp when the lamp malfunctions; and

(e) energizing the resistor responsive to the electrical signal thereby increasing the temperature of the resistor, and the thermochromic paint changing its physical appearance when the thermochromic paint reaches a threshold temperature responsive to its energization thereby indicating which lamp is not functioning.

2. The method of claim 1 wherein the electrical signal is an increase in voltage.

3. The method of claim 1 wherein the thermochromic paint loses its color to expose the resistor when the thermochromic paint reaches the threshold temperature.

4. The method of claim 1 wherein the thermochromic paint changes its color responsive to the increase in resistor temperature above the threshold temperature.

5. A light string having a plurality of lights connected in a series circuit comprising:

a plurality of lamp sockets, each socket having a first electrical wire and a second electrical wire, first and second electrical contacts within each socket, the first and second electrical wires electrically connected to the first and second electrical contacts respectively,

a miniature lamp mounted in each of the lamp sockets, each lamp electrically connected to the first and second electrical contacts when the lamp is mounted in the socket,

a power line for electrically connecting the first and second electrical wires to a power source having a line voltage, and

a resistor connected in parallel with each of the miniature lamps, the resistor associated with a thermochromic material that assumes a first condition when the lamp that the resistor is connected in parallel with is energized in an “

on”

condition, and the thermochromic paint assumes a second condition when the lamp that the resistor is connected in parallel with is burned out or non functioning when the string of lights is energized with the power from the power source.

6. The light string of claim 5 wherein when the lamp is in the “

on”

condition, the voltage across the resistor is equal to the line voltage divided by the number of lamps in the series circuit, and in the burned out or non functioning condition, the voltage across the resistor is substantially the line voltage.

7. The light string of claim 6 wherein the resistor has a base first color and is coated with the thermochromic material, the first condition being opaque and the second condition being translucent to expose the base first color when the lamp that the resistor is connected in parallel with is burned out or non-functioning.

8. The light string of claim 6 wherein the thermochromic material is a thermochromic paint having color pigment in it and the resistor is coated with the thermochromic paint, the first condition being opaque and the second condition being translucent to expose the color pigment in the paint when the lamp that the resistor is connected in parallel with is burned out or non-functioning.

9. The light string of claim 6 and further comprising a base plate coated with the thermochromic material and the base plate mounted adjacent to the resistor.

10. The light string of claim 6 wherein the resistor is mounted on the socket.

11. The light string of claim 6 wherein the resistor is mounted adjacent to the socket and electrically connected to the first and second electrical wires.

12. A light string having a plurality of lights connected in a series circuit comprising:

a plurality of sockets, each socket connected in a series circuit, and having a first electrical wire and a second electrical wire,

a miniature lamp mounted in each of the lamp sockets, each lamp electrically connected to the first and second electrical wires when the lamp is mounted in the socket,

means for electrically connecting the first and second electrical wires to a power source for providing a line voltage to the series circuit, and

signaling means connected in parallel with each of the miniature lamps, the signaling means comprising an audible alarm that is in an “

off”

condition when the lamp that the audible alarm is connected in parallel with is energized in an “

on”

condition, and the audible alarm providing an audible indication representing an “

on”

condition when the lamp that the audible alarm is connected in parallel with is burned out or non functioning when the string of lights is energized from the power source.

13. A method for indicating that an electric circuit having a resistive load connected in the circuit is energized comprising the steps of:

(a) providing a signaling device electrically connected in parallel with the resistive load;

(b) energizing the electric circuit;

[and]

(c) energizing the signaling device simultaneously with energizing the electric circuit with sufficient power to activate the signaling device when the resistive load is energized; and

(d) providing an output from the signaling device responsive to its activation thereby indicating that the resistive load has a voltage applied across it.

14. The method of claim 13 wherein the signaling device comprises a resistor connected in parallel with each lamp, the resistor increasing its temperature responsive to its energization.

15. The method of claim 14 wherein the signaling device further comprises thermochromic paint applied over the resistor, the thermochromic paint losing its color to expose the resistor when the thermochromic paint reaches a threshold temperature.

16. The method of claim 14 wherein the signaling device further comprises a thermochromic paint applied over the resistor, the thermochromic paint changing its color responsive to the increase in resistor temperature above a threshold temperature.

17. A device for indicating the presence of voltage in an electric circuit having a resistive load comprising:

a resistor electrically connected in parallel with the resistive load, the resistor having thermochromic paint applied over the resistor and connected in parallel with the resistive load, the resistor increasing its temperature responsive to a voltage applied to the resistive load, the thermochromic paint changing its physical color characteristics when the thermochromic paint reaches a threshold temperature thereby indicating that the resistive load has a voltage applied across.

18. The device of claim 17 wherein the signaling device comprises an electroluminescent light connected in parallel with the resistive load, the electroluminescent light illuminating responsive to it'"'"'s the threshold voltage applied to the resistive load.

19. A method for indicating that an electric circuit having a resistive load connected in the circuit is energized comprising the steps of:

(a) providing an electroluminescent device electrically connected in parallel with the resistive load, the electroluminescent device illuminating responsive to its energization;

(b) energizing the electric circuit; and

(c) energizing the electroluminescent device simultaneously with energizing the electric circuit thereby indicating that the resistive load has a voltage applied across it.