Abstract: Disclosed is an LED bulb having a current-compensated driving circuit. A compensation current 352 is coupled to a main driving capacitor used to power LEDs and functions to keep the load current more constant. This has dual advantages of saving power and making the light output more uniform. Saving power also means that the circuit runs cooler than without compensation. Additionally this circuit includes an inductor placed in line with a driving capacitor. The inductor functions to reduce rapid current influx to the capacitor during operation of the driving circuit, which reduces EMF and reduces component stress. One benefit of using an inductor is that most of the current absorbed by the inductor is provided back to the circuit during a later portion of the AC cycle, which also limits energy losses by the driving circuit.

Abstract: Disclosed is an LED bulb having many advantages over previous bulbs. The bulb is designed with ease of fabrication and low cost in mind. A main support is made of chromed copper, used for both its reflectivity, its readily availability, and its relative low cost. A collection of bright LEDs are electrically coupled to a driving circuit formed on a board that is housed within the main support. The LEDs are mounted on a circuit board flexible enough to form into a desired shape while rigid enough to withstand normal movements. The LED circuit board includes multiple polished or shiny areas, also called lands or panels made to reflect light away from the bulb. The panels are electrically insulated from the operating circuit and prevent injury should the bulb be broken and the components be touched, even while operating.

Abstract: A power conditioning circuit in a light bulb efficiently converts an Alternating Current (AC) input voltage into Direct Current (DC) power for operating LEDs in the light bulb. The power conditioning circuit discharges capacitors when a voltage level of the input voltage drops below a given voltage necessary to operate the LEDs. The capacitors are then recharged when the input voltage is high enough to power the LED. The capacitors are configured to operate as voltage dividers while being charged thus reducing a peak voltage level of the output voltage used for powering the LEDs. The reduced output voltage reduces the overall amount of energy used by the light bulb and reduces the amount of heat radiated by the light bulb.

Abstract: A lighting device comprises a mounting head having multiple facets each configured to retain an associated Light Emitting Diode (LED). The LEDs are mounted to the facets with a thermally conductive metal pad and thermally conductive adhesive. A connector for the lighting device inserts into a light socket and receives power for operating the LEDs. A heat transfer body is coupled between the mounting head and the connector and transfer heat generated by the LEDs downward from the mounting head and then radially outward. The mounting head, adhesive, metal pad, and heat transfer body form a heat transfer structure that more effectively removes heat generated by the LEDs. In one embodiment, a dimmer circuit is also provided that allows the LED lighting device to operate with conventional dimmer switches.

Abstract: A lighting device comprises a mounting head having multiple facets each configured to retain an associated Light Emitting Diode (LED). The LEDs are mounted to the facets with a thermally conductive metal pad and thermally conductive adhesive. A connector for the lighting device inserts into a light socket and receives power for operating the LEDs. A heat transfer body is coupled between the mounting head and the connector and transfer heat generated by the LEDs downward from the mounting head and then radially outward. The mounting head, adhesive, metal pad, and heat transfer body form a heat transfer structure that more effectively removes heat generated by the LEDs. In one embodiment, a dimmer circuit is also provided that allows the LED lighting device to operate with conventional dimmer switches.

Abstract: A power conditioning circuit in a light bulb efficiently converts an Alternating Current (AC) input voltage into Direct Current (DC) power for operating LEDs in the light bulb. The power conditioning circuit discharges capacitors when a voltage level of the input voltage drops below a given voltage necessary to operate the LEDs. The capacitors are then recharged when the input voltage is high enough to power the LED. The capacitors are configured to operate as voltage dividers while being charged thus reducing a peak voltage level of the output voltage used for powering the LEDs. The reduced output voltage reduces the overall amount of energy used by the light bulb and reduces the amount of heat radiated by the light bulb.

Abstract: A lighting device comprises a mounting head having multiple facets each configured to retain an associated Light Emitting Diode (LED). The LEDs are mounted to the facets with a thermally conductive metal pad and thermally conductive adhesive. A connector for the lighting device inserts into a light socket and receives power for operating the LEDs. A heat transfer body is coupled between the mounting head and the connector and transfer heat generated by the LEDs downward from the mounting head and then radially outward. The mounting head, adhesive, metal pad, and heat transfer body form a heat transfer structure that more effectively removes heat generated by the LEDs. In one embodiment, a dimmer circuit is also provided that allows the LED lighting device to operate with conventional dimmer switches.

Abstract: A high impedance attenuator for use in a test and measurement instrument employs compensation to adjust the low frequency attenuation to match the high frequency attenuation exhibited by the attenuator, rather than attempting to adjust the high frequency attenuation exhibited by the attenuator. In an alternate embodiment of the invention, compensation to adjust low frequency attenuation is employed in a feedback loop and an opposite compensation is applied in a parallel attenuation stage to stabilize the input resistance. In yet another embodiment of the invention, compensation to adjust low frequency attenuation is employed by means of an R-C time constant of an additional R-C circuit in a feed forward loop. This additional time constant is matched to the R-C time constant of the input R-C network. The input resistance of the attenuator is not changed.

Abstract: A high impedance attenuator for use in a test and measurement instrument employs compensation to adjust the low frequency attenuation to match the high frequency attenuation exhibited by the attenuator, rather than attempting to adjust the high frequency attenuation exhibited by the attenuator. In an alternate embodiment of the invention, compensation to adjust low frequency attenuation is employed in a feedback loop and an opposite compensation is applied in a parallel attenuation stage to stabilize the input resistance. In yet another embodiment of the invention, compensation to adjust low frequency attenuation is employed by means of an R-C time constant of an additional R-C circuit in a feed forward loop. This additional time constant is matched to the R-C time constant of the input R-C network. The input resistance of the attenuator is not changed.

Abstract: A circuit for use in a DMM utilizes an auxiliary A/D converter to measure the battery voltage of the DMM and displays the result on the LCD display screen of the DMM. The user receives a numeric indication of the battery voltage measured, rather than a simple good/bad or bar graph indication. The voltage measured provides the user with a quantitative indication which allows the user to determine how close the battery is to being exhausted. Thus, the user can be made aware of a weakened state of the battery before operation of a backlight further drains the battery to an unacceptably low level.

Abstract: A simplified user interface for an electronic test and measurement device comprises an arrangement of a segmented LCD device and a plurality of keys used to implement a softkey system, in combination with a single AMPs input connector and a rotary selector having only a single position for each basic kind of parameter to be measured. The segmented LCD device includes, at each location adjacent to a key, a plurality of segments representing a vertically-arranged list of functions to be controlled. In one embodiment of the invention, the housing of the electronic test and measurement device is fabricated to have finger-like projections overlaying a portion of the LCD screen for creating the appearance of the continuation of displayed LCD softkey separation lines.

Abstract: A delta-sigma modulator includes an integrator which includes an integrating amplifier having an input terminal and an output terminal. A pole of a first single-pole-double-throw (SPDT) switch is coupled to a first electrode of an input capacitor, while a first throw of the first SPDT switch is coupled to an input signal source, and a second throw is coupled to a source of reference potential (ground). A pole of a second SPDT switch is coupled to a second electrode of the capacitor, while a first throw of the second SPDT switch is coupled to the input terminal of the integrating amplifier. A feedback signal generator has an input terminal coupled to the output terminal of the integrating amplifier, and an output terminal directly coupled to a second throw of the second SPDT switch.

Abstract: A method by which a microprocessor based handheld multi-meter, or other handheld electronic instrument, can communicate with a computer or other microprocessor based device through the measurement input jacks of the handheld multi-meter. A handheld meter, thus equipped, can receive control or calibration data from, and provide test or calibration data to, a host computer or microprocessor based accessory or other instrument. To enable this capability, the handheld meter employs dual-signal, single-axis jacks, for example split banana jacks, for one or more of its signal and ground receptacles. The handheld meter and the computer, or another microprocessor based instrument or accessory device that the meter is to communicate with, are equipped with mutually compatible software and appropriate hardware to support single signal path communication.

Abstract: A dynamically controlled timing signal generator includes a source of a controlled current, a timing signal generating circuit coupled to the controlled current source for generating the timing signal, and a feedback circuit coupled to the controlled current source for controlling the controlled current source to produce a desired controlled current.

Abstract: An adapter suitable for use with a handheld multimeter and a thermocouple probe contains a temperature sensor and input connectors suitable for mating with standard thermocouple probes. Both of these are closely coupled thermally to an isothermal domain. Plugs suitable for mating with the input jacks of a handheld multimeter are disposed within the adapter on the other side of a high thermal resistance zone. Conductors connect these outputs to the input connectors and to the leads of the temperature sensor. A four output version of the adapter is shown for use with a three lead temperature sensor, and a three output version is shown for use with a two lead temperature sensor. The output plugs can paired to be more compact and easier to use through the use of dual-signal single-axis banana plugs.

Abstract: A method and apparatus for producing a temperature stable frequency at reduced cost. Advantage is taken of an existing, relatively temperature insensitive, low frequency and low cost watch crystal and an existing, high frequency, low cost, but relatively temperature sensitive system clock. A calibration module coupled to the watch crystal and clock calibrates the watch crystal to a reference frequency at a reference temperature and calibrates the clock to the watch crystal at an operating temperature, to relate the clock frequency to the reference frequency at any operating temperature and thereby provide a high precision, relatively temperature insensitive time or frequency base at low cost.

Abstract: A method and circuit for triggering an electronic instrument only once during a period of an input signal having multiple triggering events during that period. A signal applied to an electronic instrument, such as an oscilloscope, is acquired. Qualified triggering events occurring on the acquired signal are identified. A selected one of the qualified triggering events during the period of the applied signal causes a trigger signal output to occur, while other qualified triggering events are ignored. In the preferred embodiment a triggering event is qualified by a first comparator that compares the input signal to a first reference level and produces a predetermined logic level output if the input signal bears a predetermined relationship to the reference level. When a qualified triggering event occurs, a buffer amplifier applies the predetermined logic level to charge a capacitor, which thereafter stores some energy from the input signal and applies it to a comparator for a predetermined period of time.

Abstract: An amplifier includes first and second transistors having emitters connected to a first current source, feedback from the second transistor collector to its base being supplied through a base-emitter path of a first Darlington pair in series with a first diode. A second current source is connected to the first Darlington pair emitter. Third and fourth transistors have emitters connected to a third current source with feedback supplied from the fourth transistor collector to its base through a second Darlington pair and a second diode. The second Darlington pair emitter is connected to a fourth current source and resistively coupled to the first Darlington pair emitter.

Abstract: A compensation method and apparatus for a roughly compensated RC attenuator using fixed resistors and fixed capacitors. Any difference of the high frequency attenuation ratio from the low frequency of DC attenuation ratio is detected and corrected by using multiplier for increasing or decreasing high frequency components at the output from such RC attenuator, thereby allowing digital or remote compensation of RC attenuator without using variable capacitors.