Abstract: An electronic flash apparatus is provided with a display element positioned in the view-finder of a photographic camera so that the operator is immediately aware if the flash tube has been fired in response to the closure of the synchronous switch. The light emitting operation of this display element is controlled by use of a signal generator arranged to be responsive to the occurrence of discharge through the flash tube of the flash apparatus. With this apparatus, therefore, the operator may rely upon the appearance of this display element to insure that the firing is effected by the flash apparatus even when the object-to-camera distance is relatively small.

Abstract: An electronic flash unit for photographic purposes, with improved means for quenching the flash when sufficient light has been emitted from the flash tube. The discharge circuit of the main storage capacitor comprises the flash tube and a switch thyristor in series with each other. A quench circuit including a quenching capacitor and a quenching thyristor will deliver a quenching current to the switch thyristor when the quenching thyristor is triggered by exposure metering and flash limiting mechanism, this mechanism including a resistor, a phototransistor, and an integrating capacitor in series with each other and in parallel with a feed capacitor which supplies feed current to the exposure metering and flash limiting mechanism, and which is in parallel with the switch thyristor.

Abstract: This invention pertains to an emergency lighting circuit that operates with a high pressure, gaseous-discharge lamp and associated ballast. When the gaseous-discharge lamp goes out, after once being ignited, sufficient current is supplied to an incandescent light or lights to maintain illumination to the area normally illuminated by the lamp. The device for providing this current may vary, but generally incorporates a voltage breakdown means that receives higher voltage from the ballast when there is failure of the gaseous-discharge lamp than when the arc therein is struck. A preferred embodiment also lights the incandescent lights during initial warm-up of the gaseous-discharge lamp. The incandescent lights may also be used in a cold environment to maintain the gaseous-discharge lamp sufficiently above an ambient temperature level to make possible initial striking of the arc in the lamp when ambient temperature conditions might otherwise prevent it.

Abstract: Voltage indication means for an electronic flashing device in which a low D.C. voltage is converted to a high D.C. voltage by a DC-DC converter circuit and energy stored in a main discharging capacitor is supplied to a flashing discharge tube to fire it, wherein the charged voltage of the main discharge capacitor is indicated by utilizing the fact that the charged voltage of the main capacitor is in equivalent relation with a voltage generated in the DC-DC converter.

Abstract: An electroluminescent display device includes at least two elongated, conductive contacts substantially adjacent to and spaced from each other with at least two substantially coextensive ends. A light-emitting element is electrically coupled between the coextensive ends. An elongated insulating base is formed about and between the contacts with their elongated outer edges extending beyond the elongated sides of the base. The base extends substantially the entire length of the outer edges of the contacts and is substantially integral between such contacts.The device is fabricated in a lead frame environment, wherein the light-emitting element is bonded to a lead frame. A lens is formed over the light-emitting element. The contacts for the device, which may be slidably engageable, are formed from the lead frame. The base is formed contiguous to the lens and over the lead frame to embed the contacts within the base with edges of the contacts extending laterally beyond the surface of the base.

Abstract: The brightness of an LED display on an automobile instrument panel is independent of the battery voltage but does depend on the position of the instrument panel illumination dimmer potentiometer. The voltage applied to the LED is limited to a maximum by a zener diode control circuit and that voltage is reduced by a voltage detector circuit which senses the difference between the battery voltage and the dimmer potentiometer output voltage to reduce the LED voltage in proportion to that difference. The voltage detector circuit is disabled when vehicle parking lamps are turned off to insure maximum LED brightness in daytime driving.

Abstract: An alarm indicator system which is utilized in combination with electrically energized apparatus, the alarm indicator including a plurality of individual indicator lamps for indicating an open-circuit condition in any one of a plurality of circuits. A master alarm lamp is provided which is energized upon the energization of any one of the individual or specific indicator lamps. The electrically energized apparatus includes, as is conventional, a plurality of drive means functioning from a source of electrical power,with relay means having normally open contacts being utilized upon closure to deliver power to the drive means of the apparatus.

Abstract: A small thin console or pad has a metal proximity switch actuated by a control ring mounted on one surface, with a small light bulb within the ring. The pad is used for remote control of a load which may be a lamp, or some other electric appliance such as a radio or stereo. The pad is connected to a wall outlet unit containing a triac as a switching device for the load. The light bulb on the pad is normally at a low glow for a night light. When the metal ring is first touched the triac is turned on for the load; and when it is touched again the triac is turned off, thereby shutting off the load, while the light on the pad is brought up to full brilliance for a predetermined interval of time as a courtesy light, and then returns to the normal night light intensity.

Abstract: A correct exposure annunciator for electronic flash apparatus includes an indicator which is turned on when the voltage on a capacitor is less than a predetermined value. The capacitor is discharged in response to a control signal which indicates that proper exposure has occurred. The capacitor is then recharged until the voltage on the capacitor attains the predetermined value and turns off the indicator.

Abstract: An electronic flash apparatus includes a correct exposure annunciator which operates if light received from the subject exceeds a predetermined percentage of the required illumination.

Abstract: An electronic flash apparatus terminates the light flash when light received from the subject has reached a predetermined level. The light terminating means includes a terminating capacitor which is discharged during the termination of the flash. Annunciator control signal generating means senses when the terminating capacitor is being recharged, and produces an annunciator control signal. An annunciator receives the annunciator control signal and provides an indication that the light terminating means has terminated the flash.

Abstract: A visual indicator in parallel with a zener diode, positioned in series with a load is provided to monitor the presence of current flow in a circuit over a range of several orders of magnitude. In addition, a circuit arrangement is described to monitor the continuity and current flow in two separate parallel paths, feeding a common load in order to check the continuity of the circuitry and associated switching devices. For this purpose, a second current monitor, including a series switch, is placed in parallel with a first series arrangement of a current monitor and a switch. Alternate polarity arrangements of the respective zener diodes associated with the corresonding current monitors are illustrated to show the varing modes of operation contemplated by this invention.

Abstract: Failure inducive operating conditions of an X-ray generator tube are sensed. Some of the sensed operating conditions are events such as hot overload of the target and thermal shock of the target, while other sensed operating conditions include hot target bearing use and thermionic cathode filament heater use. Certain of the sensed operating conditions are integrated, with the integrated output being compared against a predetermined standard to yield a prediction of remaining operating life. Other sensed conditions, if present, are indicative of incipient failure without integration. The integrated signals are stored in electrochemical cells and read out periodically for a prediction of incipient tube failure.

Abstract: In a display device having a plurality of signal lamps, each lamp is coupled to a signal contact through a first decoupling diode and a test voltage having a voltage lower than that of the signal voltage is coupled to each lamp by means of a series resistance and second diode to generate a current acting both to pre-heat the lamp and for use in indicating lamp failure with a further diode coupled to the second diode providing an input to testing means giving an indication of a lamp failure.

Abstract: A channel number display device for a television receiver for displaying the numerals of the channel to which the receiver is tuned with the display being initially bright immediately after a channel change, and then after a predetermined time of several seconds, being reduced in brightness so as not to distract from the program material. Through the use of a thyristor, regardless of the number of individual elements in the numerical display, the brightness levels may be held to predetermined quantities.BACKGROUND OF THE INVENTIONOver the years, it has been a desire of television manufacturers to provide a display of the channel numbers on the television receiver so that they can be easily read, especially immediately after tuning to a new station so that the viewer can determine if he is at the desired station. This is especially true for television receivers having remote control, wherein the viewer is spaced at the viewing distance from the receiver while tuning to a new station.