End-of-life lamp starter disabling circuit

• US 5,019,751 A
• Filed: 09/15/1989
• Issued: 05/28/1991
• Est. Priority Date: 09/15/1989
• Status: Expired due to Fees

• Current Assignee: Hubbell, Inc.
• Original Assignee: Hubbell, Inc.
• Inventors: Flory, Isaac L. IV, Nuckolls, Joe A.
• Primary Examiner(s): Laroche, Eugene R.
• Assistant Examiner(s): DINH, SON T
• Application Number:
  US07/407,616
• Time in Patent Office: 620 Days
• Field of Search: 315/290, 315/289, 315/205, 315/73, 315/74, 315/104, 315/106, 315/107
• US Class Current: 315/290
• CPC Class Codes: H05B 41/042 using semiconductor devices
• CPC Class Codes: H05B 41/18 having a starting switch
• CPC Class Codes: H05B 47/20 Responsive to malfunctions or to light source life; for protection
• CPC Class Codes: Y10S 315/07 Starting and control circuits for gas discharge lamp using transistors

Abstract

A disabling circuit for deactivating a high pressure sodium lamp starting and operating circuit when the lamp exhibits end-of-life cycling includes a normally closed thermal switch connected to the starting and operating circuit is inoperative, the switch having contacts which open in response to an elevated temperature. A heating element is connected in parallel with the lamp so that the voltage across the lamp is applied to the heating element. The heating element is supported in a selected heat conducting relationship with the thermal switch so that a predetermined elevated temperature is reached and the contacts are opened only after the dissipation of an amount of energy resulting from repeatedly high lamp open-circuit voltage accompanying end-of-life cycling.

Claims

1. A disabling circuit for deactivating a gas discharge lamp starting and operating circuit when the lamp exhibits end-of-life cycling, the starting and operating circuit being of the type having an AC power source, a ballast connected to said power source, starting circuit means for supplying high-voltage, high-frequency pulses to start an extinguished lamp and lamp circuit means for connecting said starting and operating circuit to a gas discharge lamp, the disabling circuit comprising the combination of

a thermal switch having normally closed contacts responsive to a predetermined elevated temperature to open;

a heating element connected in parallel circuit relationship with said lamp circuit means so that the voltage across said lamp is applied to said element;

means for supporting said heating element in a selected heat conducting relationship with said thermal switch so that said predetermined elevated temperature is reached and said contacts are opened after an interval of time and the dissipation of an amount of energy resulting from repeatedly high lamp open-circuit voltage accompanying end-of-life cycling; and

latching circuit means connected to said contacts and to said AC source to disconnect said source from said starting and operating circuit when said contacts open and to maintain said source disconnected until said latching circuit means is manually reset;

said means for supporting said heating element in heat conducting relationship with said thermal switch including a mass of polymeric material having a predetermined thickness and means for holding said element and said switch against opposite sides of said mass.

2. A disabling circuit for deactivating a gas discharge lamp starting and operating circuit when the lamp exhibits end-of-life cycling, the starting and operating circuit being of the type having an AC power source, a ballast connected to said AC source, starting circuit means for supplying high-voltage, high-frequency pulses to start an extinguished lamp and lamp circuit means for connecting said starting and operating circuit to a gas discharge lamp, the disabling circuit comprising the combination of

a normally closed thermal switch connected in circuit relationship with the starting and operating circuit such that when said switch is open said starting and operating circuit is inoperative, said switch having contacts which open in response to a predetermined elevated temperature;

a heating element connected in parallel circuit relationship with said lamp circuit means so that the voltage across said lamp is applied to said element; and

means for supporting said heating element in a selected heat conducting relationship with said thermal switch so that said predetermined elevated temperature is reached and said contacts are opened after an interval of time during which an amount of energy resulting from repeatedly high lamp open-circuit voltage accompanying end-of-life cycling is dissipated.

3. A disabling circuit according to claim 2 wherein said contacts of said switch are connected in series circuit relationship with said starting circuit means.

4. A disabling circuit according to claim 2 and further comprising a radio frequency choke connected in series with said heating element for blocking high-voltage, high-frequency pulses produced by said starting circuit means.

5. A disabling circuit for deactivating a gas discharge lamp starting and operating circuit when the lamp exhibits end-of-life cycling, the starting and operating circuit being of the type having an AC power source, a ballast connected to said power source, starting circuit means for supplying high-voltage, high-frequency pulses to start an extinguished lamp and lamp circuit means for connecting said starting and operating circuit to a gas discharge lamp, the disabling circuit comprising the combination of

a thermal switch having normally closed contacts responsive to a predetermined elevated temperature to open;

a heating element connected in parallel circuit relationship with said lamp circuit means so that the voltage across said lamp is applied to said element;

means for supporting said heating element in a selected heat conducting relationship with said thermal switch so that said predetermined elevated temperature is reached and said contacts are opened after an interval of time and the dissipation of an amount of energy resulting from repeatedly high lamp open-circuit voltage accompanying end-of-life cycling; and

latching circuit means connected to said contacts and to said AC source to disconnect said source from said starting and operating circuit when said contacts open and to maintain said source disconnected until said latching circuit means is manually reset.

6. A disabling circuit according to claim 5 and further comprising a radio frequency choke connected in series with said heating element for blocking high-voltage, high-frequency pulses produced by said starting circuit means.

7. A disabling circuit for deactivating a gas discharge lamp starting and operating circuit when the lamp exhibits end-of-life cycling, the starting and operating circuit being of the type having an AC power source, a ballast connected to said AC source, starting circuit means for supplying high-voltage, high-frequency pulses to start an extinguished lamp and lamp circuit means for connecting said starting and operating circuit to a gas discharge lamp, the disabling circuit comprising a combination of

a normally closed thermal switch connected in circuit relationship with the starting and operating circuit such that when said switch is open said starting and operating circuit is inoperative, said switch having contacts which open in response to a predetermined elevated temperature;

a heating element connected in parallel circuit relationship with said lamp circuit means so that the voltage across said lamp is applied to said element;

voltage responsive breakdown means connected in series circuit relationship with said heating element to apply energy to said heating element when the lamp voltage exceeds a predetermined threshold; and

means for supporting said heating element in a selected heat conducting relationship with said thermal switch so that said predetermined elevated temperature is reached and said contacts are opened after an interval of time and the dissipation of an amount of energy resulting from repeatedly high lamp open-circuit voltage accompanying end-of-life cycling.

8. A disabling circuit for deactivating a gas discharge lamp starting and operating circuit when the lamp exhibits end-of-life cycling, the starting and operating circuit being of the type having an AC power source, a ballast connected to said power source, starting circuit means for supplying high-voltage, high-frequency pulses to start an extinguished lamp and lamp circuit means for connecting said starting and operating circuit to a gas discharge lamp, the disabling circuit comprising the combination of

a thermal switch having normally closed contacts responsive to a predetermined elevated temperature to open;

a heating element connected in parallel circuit relationship with said lamp circuit means so that the voltage across said lamp is applied to said element;

means for supporting said heating element in a selected heat conducting relationship with said thermal switch so that said predetermined elevated temperature is reached and said contacts are opened after an interval of time and the dissipation of an amount of energy resulting from repeatedly high lamp open-circuit voltage accompanying end-of-life cycling;

voltage responsive breakdown means connected in series circuit relationship with said heating element to apply energy to said heating element when the lamp voltage exceeds a predetermined threshold; and

latching circuit means connected to said contacts and to said AC source to disconnect said source from said starting and operating circuit when said contacts open and to maintain said source disconnected until said latching circuit means is manually reset.

9. A disabling circuit for deactivating a gas discharge lamp starting and operating circuit when the lamp exhibits end-of-life cycling, the starting and operating circuit being of the type having an AC power source, a ballast connected to said AC source, starting circuit means for supplying high-voltage, high-frequency pulses to start an extinguished lamp and lamp circuit means for connecting said starting and operating circuit to a gas discharge lamp, the disabling circuit comprising the combination of

a normally closed thermal switch connected in circuit relationship with the starting and operating circuit such that when said switch is open said starting and operating circuit is inoperative, said switch having contacts which open in response to a predetermined elevated temperature;

a heating element connected in parallel circuit relationship with said lamp circuit means so that the voltage across said lamp is applied to said element; and

means for supporting said heating element in a selected heat conducting relationship with said thermal switch including a mass of polymeric material having a predetermined thickness and means for holding said element and said switch against opposite sides of said mass so that said predetermined elevated temperature is reached and said contacts are opened after an interval of time and the dissipation of an amount of energy resulting from repeatedly high lamp open-circuit voltage accompanying end-of-life cycling.