Abstract: A flashing and sound generating lamp that repeats on-off operation and generates a characteristic audible sound when an electric current is supplied to the lamp. The lamp comprises a thermally bendable member connected in series or in parallel with the lamp filament to effect on-off energization of the filament as a result of the bending of the member due to the presence and absence of radiant heat from the filament, and a concavity is prefabricated into the thermally bendable member to cause the member to bend with a snap action thereby to generate a characteristic sound each time the lamp is turned on and off.

Abstract: High-intensity-discharge sodium lamp incorporates as a starting gas xenon at a pressure between 50 and 300 torrs, in order to improve the lamp efficiency and the spectral power distribution of the discharge. To facilitate lamp starting on a conventional pulse-type starting circuit, a trigger electrode is wrapped about the exterior of the arc tube proximate one of the lamp electrodes, with the potential applied to the trigger electrode during lamp starting being the same as that which is applied to the other or more remote lamp electrode. The starting pulse applied between the trigger electrode and the proximate lamp electrode initiates the lamp discharge. The trigger electrode also extends along the outer surface of the arc tube contiguous therewith toward the other electrode and the discharge, once initiated, progresses toward the other electrode.

Abstract: A high pressure discharge lamp with a starting circuit contained therein includes an arc tube provided with a pair of opposed electrodes at the hermetically sealed opposite ends thereof. The interior of the arc tube is filled with at least a luminous metal and gas. The discharge lamp further includes a series circuit consisting of a thermo-responsive switch and a resistor and shunted to the electrodes of the arc tube, and an outer envelope for containing therein the series circuit and the arc tube. The resistance value of the resistor is set such that a sufficient current to induce a pulse of higher voltage than the starting voltage flows through the series circuit while, on the other hand, the current flowing through the series circuit is substantially equal to or less than the lamp current during the stable state of the lamp.

Abstract: A bimetal switch circuit, which consists of the series combination of a bimetal switch and a fixed resistance, is connected in parallel with a discharge lamp which is connected across an AC power source through an inductive ballast. The bimetal switch has a heating filament which is closed at the normal temperature and opened when heated to high temperatures by the heating filament. The total resistance value R.sub.o (in ohm) of the bimetal switch circuit at the normal temperature is set so as to establish the relation V.sub.s /R.sub.o .ltoreq. 1 with the effective voltage V.sub.s (in volts) of the AC power source. Under such a condition, when the bimetal switch having been once opened at the starting of the discharge lamp is closed again, high-frequency high-voltage pulses are generated across both terminals of the bimetal switch circuit, and the discharge lamp is easily and stably lit up by the high-frequency pulse voltages.

Abstract: A discharge lamp has an electrically conducting transparent layer and a temperature control which responds to variations of the lamp current to control lamp temperature. A control member causes an auxiliary current to flow intermittently through the said layer. The temperature control is adjusted so that in the operational condition the lamp will always be operating in a voltage-current range having a positive nature. As a result, the lamp does not require an electric stabilizing ballast.

Abstract: A high pressure sodium vapor lamp utilizing an alumina ceramic arc tube within an outer glass envelope is provided with a bi-metal switch which short circuits the arc tube at starting. Current flow through the switch causes it to heat up and open the short circuit, producing a voltage pulse which starts the lamp. The bi-metal is fastened to a pin conductor extending from the metal exhaust tube of the arc tube to the frame. The pin conductor, which receives heat by conduction from the exhaust tube and is also heated by lamp current flow, transmits sufficient heat to the bi-metal to maintain it deflected during normal operation.

Abstract: The invention relates to an ignition circuit for a sunlamp, the lamp including a gas or vapor discharge tube which emits ultraviolet radiation and two infrared radiators.The ignition or auxiliary circuit uses a diode which supplies a succession of current pulses which flows through a heating resistor in the discharge tube for the purpose of ignition. Relatively high voltages between the electrodes of an electric discharge tube, for example, this discharge tube can be realized.

Abstract: An improved thermal switch permitting large temperature excursions beyond the design closure temperature without stressing the switch material beyond its elastic limits. It combines a bimetal portion with a spring portion through which movement is transmitted, the former providing sufficient deformation for closure at design temperature, and the latter accommodating excess deformation beyond closure caused by high temperature. It is particularly useful in metal halide lamps having gas filled outer envelopes and requiring shorting of an auxiliary starting electrode to the adjacent main electrode during operation.