Did You Know...
...Chester Carlson was a patent agent who tired of having to make multiple copies of patent applications using the only duplication method available at the time: carbon paper. In 1959 he came up with a new copying system and took it to IBM for evaluation. The "experts" at IBM determined potential sales to be only 5,000 units because people wouldn't want to use a bulky machine when they had carbon paper. Carlson's invention was the xerography process, the company founded on the system is Xerox.
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| Number | Title | Issue Date |
| 7602158 | Power circuit for generating non-isolated low voltage power in a standby condition A power circuit generating a non-isolating low voltage power supply using a capacitive AC voltage drop in standby. Specifically, the power circuit includes an AC connector that generates a first AC input and a second AC input that are opposite in phase. The power ci... | 10/13/2009 |
| 7579813 | Power regulator having a voltage regulator module and having a voltage buffer module to provide a constant voltage output A power regulator with a constant-voltage output is provided, which includes a voltage regulator module and a voltage buffer module, wherein the voltage regulator module is spaced from a load by the voltage buffer module, so that an output voltage of the voltage reg... | 08/25/2009 |
| 7245511 | Resistor dropper power supply with surge protection A power supply system and corresponding methodology is provided for providing a self-protected power supply for use with electronic electricity meters. The self-protecting features are provided, in part, through the use of surface mounted resistive components corres... | 07/17/2007 |
| 6925419 | Intrinsically safe field maintenance tool with removable battery pack An intrinsically safe field maintenance tool includes terminals selectably coupleable to a process communication loop having a process industry standard communication protocol. At least one media is configured to communicate in accordance with a process industry sta... | 08/02/2005 |
| 6275013 | Switching power supply employing an internal resistance in series with a zener diode to stabilize a DC output A switching power supply includes a rectifying and smoothing circuit 6 coupled to an inductor L1 and a zener diode D2 coupled to the output of the rectifying and smoothing circuit 6. An internal resistor on the inductor L1 side viewed through the rectifyi... | 08/14/2001 |
| 6222350 | High temperature voltage regulator circuit A high voltage shunt regulator circuit includes a high voltage device with a predetermined reverse-conduction threshold connected in series with a thermal compensation device comprising a plurality of gate threshold amplifiers connected in series with one... | 04/24/2001 |
| 6061577 | Electrical power supply circuit, in particular for portable appliances An electricity power supply circuit for an external appliance whose consumption varies over time. The circuit comprises an electrochemical cell, a supercapacitor serving as a source of electricity for said appliance, and a chopper voltage converter betwee... | 05/09/2000 |
| 5701071 | Systems for controlling power consumption in integrated circuits Systems for controlling the current consumption of an integrated circuit chip and the like so as to reduce the inductive voltage drops occurring over the power supply lines within the chip and power supply lines to the chip are disclosed. The systems acco... | 12/23/1997 |
| 5568043 | Dual voltage generation circuit A dual voltage generation circuit, responsive to a switching signal, to selectively generates a constant voltage at an output terminal is provided. The generation circuit comprises a switch transistor, a first and a second zener diodes and a diode. As the... | 10/22/1996 |
| 5457623 | High efficiency power converter having diode-controlled switching frequency for illumination loads A high power, high efficiency power converter for illumination loads, with low heat dissipation. In the preferred embodiment, the converter utilizes a switching means pair providing a high frequency inverter, provided by a pair of FETs, each arranged in o... | 10/10/1995 |
| 5304861 | Circuit for the detection of temperature threshold, light and unduly low clock frequency A detection circuit that does not vary with the supply voltage is formed by measuring the voltage generated at the terminals of a diode (1) which is reverse biased and is supplied by a constant current generator (2). Furthermore, the generator (2) is impr... | 04/19/1994 |
| 5291365 | Power supply with overvoltage protection circuit First, second, and third power supply lines are separate from each other. A power supply circuit receives electric power from the first power supply line, and generates a given power supply voltage from the received electric power and outputs the generate... | 03/01/1994 |
| 5252908 | Apparatus and method for temperature-compensating Zener diodes having either positive or negative temperature coefficients An auto-TC voltage reference wherein an operational amplifier receives at one input the voltage of a Zener diode and at its other input receives a compensation signal from a feedback circuit comprising a transistor and resistor network. When one of the re... | 10/12/1993 |
| 5227963 | Flat-top waveform generator and pulse-width modulator using same A three-phase flat-top waveform generator which may be utilized in a pulse-width modulator. Transfer function means receive a three-phase input signal and produce therefrom a zero sequence signal. Under steady-state and balanced conditions, the zero seque... | 07/13/1993 |
| 5027165 | Buried zener diode An improved zener diode formed in a semiconductor wafer having a primary surface, the zener diode having a PN junction buried beneath the surface. The diode includes a pair of spaced contacts on the surface, the first located on one region and the second ... | 06/25/1991 |
| 4994731 | Two wire and multiple output Hall-effect sensor A device for sensing the speed of a rotating element in a vehicle replaces the practice of using magnetic wire coil pickup devices placed in close proximity to a rotating element, such as a gear. The main speed sensing component is a conventional three le... | 02/19/1991 |
| 4982318 | DC power supply having bipolar outputs A DC power supply which is adapted to produce a DC main voltage between a main output terminal provided at one end of a first line and a ground terminal provided at one end of a second line; the power supply being characterized in that there is disposed a... | 01/01/1991 |
| 4982316 | Polyphase full-wave rectifying circuit A polyphase full-wave rectifying circuit that is connected to a polyphase AC line having a neutral point includes DC output terminals and plural pairs of rectifying elements. Each pair is composed of two rectifying elements in series and these pairs are c... | 01/01/1991 |
| 4868907 | Self-biased scorotron grid power supply and electrostatic voltmeter operable therefrom An electrophotographic system including a corona charging device for applying a charge to a surface and having a coronode driven to a corona producing condition; a conductive grid interposed between the surface to be charged and the coronode; the conducti... | 09/19/1989 |
| 4794277 | Integrated circuit under-voltage lockout A low voltage lockout circuit preferably of integrated circuit form to provide a lockout signal when an internally generated reference voltage is insufficient. According to the present invention, a reference voltage is produced by passing a constant curre... | 12/27/1988 |
| 4774452 | Zener referenced voltage circuit A zener diode is connected at one end via a first impedance to a first power terminal. The base-to-emitter junctions of first and second transistors are connected in parallel between the other end of the zener diode and a second power terminal. The collec... | 09/27/1988 |
| 4764716 | Stabilizing circuit for a microcomputer A stabilizing circuit for the operating voltage of a microcomputer, in which the input of the circuit is connected to a power supply, and the output of the circuit is connected to the operating voltage-input of the microcomputer. Connected in parallel wit... | 08/16/1988 |
| 4748533 | Integrated circuit for the protection of subscriber lines against overvoltages An integrated circuit for protecting subscriber lines against overvoltages includes a semiconductor body; a field-controllable thyristor having a gate electrode, an anode electrode and a cathode electrode, the gate electrode being insulated from the semic... | 05/31/1988 |
| 4701835 | Multimode flashlight A flashlight which can be operated directly either by a rechargeable batt or by a hand-cranked alternator. The alternator can also simultaneously operate the light and recharge the battery, or only recharge the battery. The alternator is integrally attac... | 10/20/1987 |
| 4695784 | Voltage and current limiting phase-triggered battery charger with continuous optimization of charging rate A battery charging circuit includes a silicon controlled rectifier full wave bridge that has its input connected across a conventional 60 hertz alternating current power line. The output of the bridge provides 120 hertz pulsating direct current to the bat... | 09/22/1987 |
| 4686449 | JFET current source with high power supply rejection A JFET current source compensates for variations in the voltage supply to intain a constant current level at its output terminal. Series connected diodes are used as voltage dividers in conjunction with a second JFET to establish the gate voltage of a thi... | 08/11/1987 |
| 4668903 | Apparatus and method for a temperature compensated reference voltage supply A voltage reference supply circuit is described that provides temperature compensation over a wide range of temperatures. The circuit includes a plurality of thermistor temperature dependent elements and these thermistor elements are utilized to compensat... | 05/26/1987 |
| 4665355 | Off line capacitor-divider power supply for solid state power controller A solid state power controller off-line capacitor divider power supply coupler between an ac voltage source output terminal and neutral terminal, supplying regulated dc voltage levels referenced to the ac voltage source output terminal to a load such as t... | 05/12/1987 |
| 4657347 | Liquid crystal display with zener diode A liquid crystal display apparatus includes a liquid crystal display device having a plurality of display digits, a one-chip microcomputer having a plurality of voltage terminals for driving the liquid crystal display device by selectively supplying the v... | 04/14/1987 |
| 4639551 | Regulated power supply circuit particularly for telephone set The invention relates to power supply circuits, and in particular those used for directly supplying, from a telephone line, the bell or other items in a telephone set. In order to avoid unacceptable crosstalk or distortion due to saturation of the power s... | 01/27/1987 |
| 4609863 | Power supply providing stabilized DC from an input voltage of AC superposed on DC without disturbing the input voltage This power supply device comprises a voltage regulating element, a constant-current source, first and second constant-current circuits, and a current switching circuit interposed between the first and second constant-current circuits and the constant-curr... | 09/02/1986 |
| 4608529 | Constant voltage circuits A constant voltage circuit has two rails 10 and 12, with one rail 12 at a variable potential V, possibly supplied by a voltaic cell. In one arm between the rails there is voltage reference means Z1, 14, with a circuit output line 16 connected thereto, and... | 08/26/1986 |
| 4603289 | Dual input voltage regulator The invention is a dual input voltage regulator that has four active parts: a transistor, a resistor, a zener diode and a capacitor. It has one input for main power and one input for turn on power. The dual input allows lower main input voltage and allows... | 07/29/1986 |
| 4591728 | Transformerless power unit A transformerless power unit for an electronic apparatus, preferably a horological instrument, including a fluorescent display, with a compensating resistor network which is connected with one pole of the supply voltage, preferably of a series circuit con... | 05/27/1986 |
| 4580206 | Voltage clamp regulator A 12 volt input is supplied to a timer providing a square wave output with an approximately 50% duty cycle. The output is applied to the bases of a pair of transistors and the collectors of the transistors conduct when a drive motor is in either the forwa... | 04/01/1986 |
| 4562400 | Temperature-compensated zener voltage reference A precision voltage reference comprising an IC chip having a Zener diode connected to the input of an operational amplifier. Variations in output with temperature are minimized by selectively controlling the Zener current in accordance with temperature. T... | 12/31/1985 |
| 4524317 | Precision, dynamic low voltage measurement system A voltage divider used to supply multiple reference voltages is energized electrically, in shunt, by a constant voltage generator and, in series, by a constant current generator. The magnitude of current supplied by the constant current generator determin... | 06/18/1985 |
| 4417198 | Average responding RMS indicating type transducer Transducers of the average responding RMS indicating type are disclosed that are particularly useful for monitoring currents and voltages in a power distribution network. The transducer includes transformer, inductively compensated voltage divider, active... | 11/22/1983 |
| 4398142 | Kelvin-connected buried zener voltage reference circuit An improved voltage reference circuit is provided comprising a series combination of a Kelvin-connected buried zener diode and a transistor. The collector of the transistor is connected to the first anode of the diode while the base of the transistor is c... | 08/09/1983 |
| 4390829 | Shunt voltage regulator circuit A series shunt regulator circuit suitable to be fabricated in monolithic circuit form for providing a regulated output voltage and having a low input to output voltage differential thereacross. The regulator is comprised of a passive PNP current mirror ci... | 06/28/1983 |
