Other

Tenna Corporation

Ole K Nilssen

Dale E Fiene

Martin J Nagel

Stanley B Goss

Donald M Berlin

Clifford E Mensing

An LED lamp that couples a heatsink with LEDs mounted on it to a glass envelope with a surface area equivalent to approximately that of a conventional light bulb, and by using a coolant vapor within the glass envelop, the lamp can be made much lighter and more cheaply. The heat generated by the LEDs is dissipated by the glass surface and not conducted into the heatsink. The heatsink can thus be mostly for the power supply. This allows for a reduced operating temperature for the power supply components that allows for a longer expected life for the power supply. In addition, the LED light bulb of the present invention can have nearly the same shape and appearance as a standard incandescent bulb. The invention can also have an advanced flyback power supply.

Vapor lamp assembly technique

An inverter is powered from a DC voltage whose instantaneous absolute magnitude is equal to that of the AC power line voltage except for being prevented from falling below a level equal to half the peak of the power line voltage. The inverter's output is loaded via a series-tuned high-Q LC circuit. Two fluorescent lamps are loading the secondary winding of a transformer whose primary winding is connected across the capacitor of the LC circuit. The magnitude of the voltage present across the capacitor is normally limited by the loading of the fluorescent lamps. However, with the lamps removed, if not expressly prevented from doing so, the magnitude of the voltage across the capacitor will increase to a destructive level due to Q-multiplication. To prevent this, an auxiliary winding on the transformer is used for limiting the magnitude for the voltage across the capacitor by rectifying the output from the auxiliary winding and feeding the resulting DC to the inverter's input; whereby the magnitude of the voltage across the capacitor will be limited to a level determined by the instantaneous magnitude of the DC voltage; which level is set such as to result in acceptable lamp starting while at the same time preventing any voltage-limiting from taking place at any time as long as the lamps are operating.

Series-resonant ballast having overload control

A push-pull inverter is supplied from an inductively current-limited DC voltage source by way of a center-tap on a transformer having significant inductance. This transformer inductance is parallel-coupled with a capacitance means. The inverter is made to self-oscillate through positive feedback provided by way of a saturable current transformer. The inverter frequency is determined by the saturation time of this current transformer, which saturation time is designed to be somewhat longer than the half-cycle period of the natural resonance frequency of the transformer inductance combined with the capacitance means. By controlling the length of this saturation time, the magnitude of the current provided to the fluorescent lamp is controlled, thereby permitting control of the light output in response to changes in the magnitude of the power line voltage.

Parallel-resonant inverter-type fluorescent lamp ballast

In an electronic ballast, a half-bridge inverter is powered from a DC voltage and provides a 40 kHz squarewave inverter output voltage. The DC voltage is obtained via a pre-converter with a control input operative to permit control of the magnitude of the DC voltage. The 40 kHz squarewave inverter output voltage is applied across a series-resonant L-C circuit, thereby establishing a 40 kHz sinusoidal voltage across the L-C circuit's tank capacitor. By controlling the symmetry of the squarewave voltage, the magnitude of the 40 kHz sinusoidal voltage is regulated to be appropriate to instant-starting a gas discharge lamp. Each of several instant-start fluorescent lamps is series-connected with a capacitor, such as to form several lamp-capacitor series-combinations, each of which is connected across the tank capacitor, thereby to be properly ignited and powered from the magnitude-controlled 40 kHz sinusoidal voltage. To attain imroved efficiency of operation, after the lamps have all ignited, the magnitude of the 40 kHz sinusoidal voltage is reduced, thereby minimizing the amount of reactive power having to be handled by the various reactive circuit components.

Ballast for parallel-connected lamps

Parallel-resonant bridge inverter

In a high-frequency electronic ballast, a screw-in fluorescent lamp is connected with and powered by way of a series-resonant LC circuit. A resistive load is connected with the LC circuit, thereby to constitute a load therefor before ignition of the fluorescent lamp or in case the fluorescent lamp were to fail to ignite.

Electronic ballast cathode heating circuit

In an electronic ballast, a rapid start fluorescent lamp is powered by being parallel-connected with the tank-capacitor of a series-resonant LC circuit. Beating power for the lamp's cathodes is obtained by way of loosely-coupled auxiliary windings on the tank inductor of the LC circuit. In case the fluorescent lamp were to be disconnected or otherwise were to fail to properly load the series-resonant LC circuit, due to so-called Q-multiplication, the magnitude of the voltage develped across the tank-capacitor would normally increase to a high and potentially destructive level. However, due to feedback operable to cause the inverter frequency to increase as a function of the magnitude of the voltage across the tank-capacitor, the magnitude of this tank-capacitor voltage is limited to a level substantially lower than what otherwise would be the case.

Electronic ballast with over-voltage protection

A frequency-converting power supply is mounted on a power plug operable to be plugged into and held by an ordinary household electric power receptacle. Through an inductive internal impedance, the power supply provides a 20-40 kHz output voltage to a pair of output terminals that connect, by way of a female plug at the end of a light-weight power cord, with the input terminals of a fluorescent lamp assembly; across which input terminals is connected a capacitor of such capacitance value as to resonate with the power supply's inductive internal impedance, thereby providing the required lamp starting voltage and operating current. Also across the input terminals is connected a series-combination of a first instant-start fluorescent lamp and a special (normally shorted) female receptacle adapted to receive and disconnectably hold a special male plug; which, in turn, is connected with the terminals of a second instant-start fluorescent lamp. Thus, by way of disconnectable plug-receptacle means, one, two or more instant-start fluorescent lamps may be series-connected and properly started and operated from the frequency-converting plug-in power supply.

Plug-in fluorescent lighting system

An inverter-type fluorescent lamp ballast is, via a light switch, powered from the power line by way of two power conductors and one control conductor. From the light switch, which contains a switch means as well as an adjustment means, the control conductor is provided with an adjustable-magnitude DC voltage; which DC voltage is referenced to one of the power conductors. At the ballast, the DC voltage is introduced into the ballast circuitry via a diode, thereby to establish within the ballast a control voltage of magnitude substantially equal to the DC voltage. This control voltage is used for controlling the magnitude of the ballast's 30 kHz output current, thereby providing for light output control. The ballast itself is a self-oscillating half-bridge inverter loaded via a series-tuned high-Q LC circuit connected across its output. A pair of fluorescent lamps is series-connected across the tank-capacitor of the LC circuit. The inverter has two bipolar transistors, each driven by an associated saturable current transformer that provides for a transistor ON-time dependent upon the magnitude of an associated bias voltage. One of the transistors has a control arrangement connected in circuit with its associated saturable transformer and is operative to control the magnitude of its associated bias voltage. As the magnitude of this bias voltage is controlled, the magnitude of the lamp current is correspondingly controlled. The magnitude of the bias voltage is controlled as a function of the magnitude of the DC voltage.

Electronic ballast with output control feature

In a high-frequency electronic ballast, a fluorescent lamp is connected with and powered by way of a series-resonant LC circuit. A resistive load is connected with the LC circuit, thereby to constitute a load therefor before ignition of the fluorescent lamp or in case the fluorescent lamp were to fail to ignite.

Compact screw-in fluorescent lamp

A special telephone instrument has a cordless hand-piece and one or more base-stations. Each base-station is hard-wire-connected with the ordinary telephone utility system and may include a built-in cellular transceiver. The hand-piece, which is powered by a built-in rechargeable battery, is--within its maximum cordless range (e.g., 500 feet)--connected with its nearest base-station via two-way radio transmission. When not in use, the hand-piece is at times resting in a cradle at its nearest base-station, thereby getting its battery recharged. When in use, the hand-piece is removed from its cradle. When so removed, the hand-piece may--while located within cordless range--be used for receiving and/or placing phone-calls via any one of the base-stations. When moved outside of cordless range, the hand-piece automatically converts to a cellular telephone, thereby permitting--not only the continuation of an ongoing conversation--but also the receiving and/or placing of telephone calls in any location served by a cellular telephone system. Thus, a person may have a base-station in his office whereat his cordless hand-piece is cradled most of the time during office hours, thereby maintaining the built-in battery fully charged. When he leaves his office, he would bring his cordless hand-piece (and his conversation) along; which hand-piece, after being removed outside of its cordless range, will automatically convert to a cellular telephone. Then, when he gets home after work, he would place his hand-piece into the cradle of another base-station; which hand-piece would automatically convert back to a regular cordless mode after having come within the cordless range of this other base-station.

Combination cordless-cellular telephone system

A power supply is adapted to be powered from an ordinary electric utility power line, or alternately from a standby storage battery, and is operable to provide a power-line-isolated output of 120 Volt RMS at a frequency of about 30 kHz. The Volt-Ampere product available from this power supply is limited to be no more than 100 Volt-Ampere. Due to the high frequency, the electric shock hazard associated with this 120 Volt/30 kHz power supply is not higher than it is for a power supply voltage a voltage of only 30 Volt RMS at 60 Hz. The power supply is used to provide shock-hazard-free and fire-initiation-hazard-free electric power for an auxiliary power distribution system in a home. Due to the Volt-Ampere limitation and the absence of shock-hazard, the power distribution can safely be done by way of so-called bell wire installation and without requiring the services of a licensed electrician. Due to the battery back-up feature, this auxiliary power distribution system can provide uninterruptible power to critical loads such as computer terminals, security systems, smoke/fire alarms, safety lighting, etc.

Auxiliary power distribution system

An electronic ballast is powered from a constant-magnitude DC supply voltage and provides a high-magnitude high-frequency voltage at a ballast output across which are connected two lamp-ballast series-combinations, each consisting of an instant-start fluorescent lamp series-connected with a ballasting capacitor. An auxiliary capacitor is connected in series with the ballast output, thereby having the total ballast output current flowing through it and causing an auxiliary high-frequency voltage to develop across its terminals. The constant-magnitude DC supply voltage is provided via a series-combination of a power-line-connected rectifier delivering an unfiltered full-wave-rectified power line voltage across a pair of rectifier DC terminals and an auxiliary DC power supply delivering an auxiliary DC voltage across a pair of auxiliary DC terminals from which, under open circuit condition, is available a DC voltage of magnitude equal to the peak magnitude of the full-wave-rectified power line voltage. Under short circuit condition, the absolute magnitude of the auxiliary DC current delivered from the auxiliary DC terminals is equal to the peak absolute magnitude of the sinusoidal current intended to be drawn from the power line under normal ballast operation. Via a transformer and rectifiers, the auxiliary DC voltage and current are derived from the auxiliary high-frequency voltage. As an overall result, the current drawn from the power line is in fact nearly sinusoidal.

Ballast with active power factor correction

A fluorescent lighting system has: (A) a central power supply including: (i) a parallel-resonant self-oscillating bridge inverter operative to provide a 35 kHz sinusoidal output voltage at a pair of primary output terminals; (ii) a tank-inductor and a tank-capacitor parallel-connected across the primary output terminals; and (iii) plural pairs of secondary output terminals, each connected with the primary output terminals via its own dedicated current-limiting sub-circuit; thereby to prevent a load connected therewith from drawing more than a certain amount of power; thereby, in turn, to render each pair of secondary output terminals fire-hazard-safe and shock-hazard-safe; each pair of secondary power output terminals being connected with its own power output receptacle; and (B) a light-weight power cord plug-in-connected with one of the power output receptacles and having a pair of power conductors between which are connected a number of individually ballasted lighting units; each lighting unit having at least one gas discharge lamp as well as a high-power-factor ballasting assembly that includes a tuned parallel-connected LC circuit having a natural resonance frequency equal to that of the output voltage provided from the central power supply. Due to having each lighting unit parallel-resonant at the frequency of the output voltage, the drastic frequency change and concomitant loss in per-lamp light output usually occurring when adding several separately ballasted lamp loads to the output of a parallel-resonant self-oscillating power supply will not occur.

Electronic ballast products and systems

Unfiltered full-wave-rectified 60 Hz power line voltage is supplied to a first self-oscillating series-resonance-loaded inverter, the high frequency output current from which is magnitude-controlled, rectified and used for maintaining a substantially constant-magnitude DC voltage on an energy-storing capacitor. This constant-magnitude DC voltage is used in combination with the unfiltered full-wave-rectified 60 Hz power line voltage for powering a second self-oscillating series-resonance-loaded inverter, the high frequency current output from which is used for powering a fluorescent lamp load. By frequency-modulating the first inverter at a 120 Hz rate, the current drawn from the power line is made to be of such waveshape as to result in a power factor well in excess of 90% while at the same time having a content of under 20% of odd triplets of third harmonic currents. The high frequency current provided to the fluorescent lamp load has a crest factor not in excess of 1.7.

Growing community of inventors

Barrington, IL, United States of America

Ole K Nilssen