Abstract: A high intensity discharge lamp having an inner tube in which a discharge takes place to produce visible light and ultraviolet radiation and an outer envelope which blocks harmful ultraviolet radiation. An element is provided to extinguish the discharge when the outer envelope is broken.

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 socket for mounting an electrical device such as an ordinary incandescent light bulb and enabling the electrical device to be switched to either its "off" condition or its "on" condition in response to touching the socket housing or any part of the structure electrically connected to the socket housing. All electrical components required to effect this switching of the power to the electrical device are mounted within the socket housing. The socket is usable with alternating current electrical power, and switching of the power to the electrical device occurs only when the voltage is passing through its zero point, thus avoiding current surges and lengthening the life of the light bulb or other controlled electrical device.

Abstract: A rapid start fluorescent lamp contains a circuit opening device on the cathode mount which opens a short time after lamp starting and stops heater current flow to the cathode.

Abstract: A lamp is described having an internal switch for keeping at least one filament incandescent for a predetermined time after an external switch indicates the user wishes to turn the lamp off.

Abstract: A high intensity discharge lamp in which the arc tube is located within an outer envelope. A multi-filament assembly is located within the outer envelope in series with the current supply to the arc tube. When the lamp outer envelope is broken, the filaments will burn out in the presence of air, open the current supply to the arc tube and extinguish the arc. The use of multi-filaments permits better control of the filament burn out time.

Abstract: There is provided in combination with a rapid-start series-sequence type ballast for two low-pressure mercury discharge lamps, apparatus for reducing the power consumption of both lamps. The apparatus utilizes switch means in conjunction with a capacitor to limit the current supply to the lamps after the lamps are energized. The switch means has two members in series circuit arrangement with one of the electrodes of one of the lamps. Each member is connected on opposite sides of the electrode. The capacitor is connected in parallel circuit arrangement with one of the members. Initially upon energization the switch means has a low impedance state to permit current flow and then switches to a high impedance state. The switch means permits preheating of the electrode and thereafter upon response to current flow switches and causes the lamp current to pass through the capacitor and thereby decrease by a predetermined amount the current through the normally operating lamps.

Abstract: HID lamp has a spring-loaded safety switch positioned between the outer protective envelope and the arc tube and electrically connected in series with one of the lamp electrodes. When the lamp is operating normally, the safety switch is maintained in the closed position, but if the outer envelope is accidentally broken, the switch automatically opens to break the lamp energizing circuit and render the lamp inoperative.

Abstract: A discharge lamp for connection to an associated alternating current power supply. The lamp is provided with two main electrodes and a starting electrode. Two diodes are connected in series, in cathode to anode relationship, between one associated AC power conductor and the starting electrode. In parallel with the diodes is a first capacitor. Connected to the junction between the diodes is a second capacitor which is connected on the other side thereof to a conductor from the other AC power conductor to the main lamp electrode remote from the starting electrode. In operation the second capacitor substantially changes its capacitance responsive to the temperature present with the lamp to effectively make the voltage doubler inoperative.

Abstract: The inner arc tube of some jacketed discharge lamps transmits ultraviolet radiation which is normally absorbed without harm by the glass outer envelope but may be released should the outer envelope be broken off. This is prevented by a fuse heater and shunting thermal switch connected in series with the arc tube and located within the outer envelope. Should the outer envelope be broken, air cools the switch so that it opens. Current flow through the heater now raises its temperature and causes it to oxidize, thereby opening the circuit and disabling the lamp.

Abstract: HID lamp has resilient safety switch positioned proximate the inner surface of the dome portion of the protective outer envelope in contact with an extremity of a resilient leaf-spring support portion of the arc tube frame, to maintain the switch in a closed position. When the envelope is shattered, the normally closed switch will open to break the electrical path to the arc tube, thereby rendering the lamp inoperative.

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: A filament coil is connected in series with an arc tube to form a self ballasted lamp. An internal starting coil is connected across the arc tube through a bimetal switch, which is normally closed, for energizing the starting coil. When an arc is struck and the tube temperature rises, the bimetal switch opens to cut out the starting coil. A fuse wire is connected across the bimetal switch to facilitate flashing of the filament coil by application of less than rated voltage during evacuation of the lamp envelope when the bimetal switch is normally open because of the elevated temperatures required for glass working and sealing. Upon subsequent application of rated voltage, the fuse wire melts and the lamp operates in its normal manner.