Voltage regulated light string

• US 6,597,125 B2
• Filed: 05/08/2002
• Issued: 07/22/2003
• Est. Priority Date: 05/17/2001
• Status: Expired due to Fees

• Current Assignee: JLJ, Inc.
• Original Assignee: JLJ, Inc.
• Inventors: Janning, John Louis
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Tran, Chuc D
• Application Number:
  US10/141,156
• Publication Number:
  US 20020171371A1
• Time in Patent Office: 440 Days
• Field of Search: 315/185.R, 315/185.S, 315/122, 315/129, 315/132, 315/130, 315/123, 315/92, 315/186, 315/312, 315/126, 315/119, 315/125, 315/324
• US Class Current: 315/185.00R
• 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
• CPC Class Codes: H05B 47/23 of two or more light sources connected in series

Abstract

A string set of series-connected incandescent flasher type lamps in which substantially all of the lamp filaments in the set are individually provided with a voltage regulated shunt circuit, which includes a voltage responsive silicon semiconductor device, which operates in one of two conducting states, neither of which is greater than about 200 ohms. When the flasher lamp is in the “on” or illuminated state, the silicon semiconductor voltage regulating shunt device is in a low impedance state. When the flasher is in the “off” state, the impedance of the silicon semiconductor device is in a lower impedance state equal to or slightly greater than the parallel equivalent impedance of silicon semiconductor device in parallel with the normal operating impedance of the flasher lamp.

Claims

1. A lighting apparatus comprising:

a string of lamps connected in series; and

a shunt circuit connected in parallel across at least one of the lamps, said shunt circuit comprising a voltage responsive silicon semiconductor device which presents a relatively low impedance level during normal operation of said lamp and which changes to a relatively lower impedance level upon an increase in voltage across the shunt,

wherein said relatively low impedance level is less than about eight times a normal operating impedance of said one of the lamps,

wherein said relatively lower impedance level is equal to or slightly greater than the parallel equivalent impedance of the shunt circuit in parallel with the normal operating impedance of said one of the lamps.

2. The lighting apparatus of claim 1 further comprising:

additional shunt circuits,

wherein each of the lamps is connected in parallel with one of the shunt circuits.

3. The lighting apparatus of claim 2 wherein substantially all of the lamps are flasher lamps.

4. The lighting apparatus of claim 1 wherein the relatively low impedance level is between about two and eight times the normal operating impedance of the lamp.

5. The lighting apparatus of claim 1 wherein the relatively low impedance level is between about two and four times the normal operating impedance of the lamp.

6. The lighting apparatus of claim 1 wherein the shunt circuit comprises at least one Zener diode.

7. The lighting apparatus of claim 1 wherein the shunt circuit comprises two Zener diodes connected in a back-to-back configuration.

8. The lighting apparatus of claim 1 wherein the shunt circuit comprises a diode array.

9. The lighting apparatus of claim 2 wherein the lamps are all non-flashing lamps.

10. The lighting apparatus of claim 2 wherein the lamps are a mixture of flashing and non-flashing lamps.

11. The lighting apparatus of claim 1 wherein the shunt circuit operates as a voltage regulated shunt circuit.

12. The lighting apparatus of claim 1 wherein said relatively low impedance level is less than about 200 ohms.

13. The lighting apparatus of claim 1 wherein said relatively low impedance level is less than about 100 ohms.

14. A lighting apparatus supplied by an alternating current (AC) supply signal comprising:

a lamp comprising a lamp filament, a first terminal and a second terminal, said lamp filament having a normal operating impedance when lighted; and

a shunt circuit connected between the first terminal and the second terminal, said shunt circuit comprising a voltage responsive silicon semiconductor device and, when the first derivative of the AC supply signal is about zero, operating at a sustaining level or a lamp filament replacement level,

wherein when operating at said sustaining level, said shunt has a low impedance level less than about eight times the normal operating impedance of the filament,

wherein when operating at said lamp filament replacement level, said shunt has a lower impedance level equal to or slightly greater than the parallel equivalent impedance of the shunt circuit in parallel with the normal operating impedance of the filament.

15. A lighting apparatus supplied by an alternating current (AC) supply signal comprising:

a lamp comprising a lamp filament, a first terminal and a second terminal; and

a shunt circuit connected between the first terminal and the second terminal, said shunt circuit comprising a voltage responsive silicon semiconductor device,

wherein when said lamp is lighted, the current through said shunt is at least 20% of the total current through the lamp and the shunt.

16. The lighting apparatus of claim 15 wherein the lamp is a flasher lamp.

17. The lighting apparatus of claim 15 wherein the shunt circuit comprises at least one Zener diode.

18. The lighting apparatus of claim 15 wherein the shunt circuit comprises two Zener diodes connected in a back-to-back configuration.

19. The lighting apparatus of claim 15 wherein when said lamp is lighted, the current through said shunt circuit is at least 30% of the total current through the lamp and the shunt.