Integrated igniter base for ceramic metal halide light source
AssigneeOsram Sylvania Inc.
InventorsAndrew Johnsen, Glenn Freeman
Life of this patent
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Abstract
A PAR38 light source assembly for use with a fixture having PAR38 socket connected to a ballast circuit for generating a ballast voltage. An electrically insulating housing supports a PAR38 screw base and encloses a CMH lamp and a circuit board providing a high voltage to ignite or re-ignite the lamp. The housing supports a reflector a lens wherein the lens, the reflector and the housing form an electrically insulating enclosure so that the PAR38 screw base is the only electrically conductive portion.
Claims20
A light source assembly for use with a fixture having a socket connected to an external ballast circuit for generating a ballast voltage, the light source assembly comprising:
- a ceramic metal halide (CMH) lamp;
- a screw base that engages the socket, to electrically connect the light source assembly to the external ballast circuit and to conduct the ballast voltage when the screw base engages the socket;
- a circuit board having mounted thereon a igniter circuit electrically connected to the screw base to receive the ballast voltage from the external ballast circuit, the igniter circuit also electrically connected to the CMH lamp to selectively energize or re-energize the lamp with a high voltage generated by the igniter circuit using the ballast voltage received from the external ballast circuit via the screw base;
- an electrically insulating reflector to receive the CMH lamp;
- an electrically insulating lens supported by the reflector so that the reflector and the lens enclose the CMH lamp;
- and
- an electrically insulating housing supporting the screw base and enclosing the CMH lamp and the circuit board, the housing supporting the reflector and lens;
- wherein the lens, the reflector and the housing form an electrically insulating enclosure so that the screw base is the only electrically conductive portion of the light source assembly;
- and
- wherein the high voltage to energize or re-energize the lamp is contained within the electrically insulated housing and none of the high voltage is external to the light source assembly.
An igniter circuit for a light source assembly for use with a fixture having a socket connected to an external ballast circuit to generate a ballast voltage, wherein the light source assembly includes a ceramic metal halide (CMH) lamp, a screw base that engages the socket to electrically connect the light source assembly to the external ballast circuit and to conduct the ballast voltage when the screw base engages the socket, the igniter circuit comprising a circuit board having mounted thereon:
- a voltage multiplier circuit for connection to the screw base and to receive the ballast voltage from the external ballast circuit via the screw base when the screw base is engaged with the socket, the voltage multiplier circuit to multiply the ballast voltage to a multiplied voltage;
- a capacitor connected to the voltage multiplier circuit to store the multiplied voltage;
- a transformer connected to the voltage multiplier circuit and for connection to the CMH lamp to step up the multiplied voltage stored by the capacitor and to supply the stepped up voltage to the lamp;
- and
- a spark gap device connected between the transformer and the capacitor to selectively discharqe the stored voltage to iqnite or re-ignite the lamp, wherein the high voltage to energize or re-energize the lamp is contained within the electrically insulated housing and none of the high voltage is external to the light source assembly.
Dependencies are inferred from the claim text.