Famous Patents
The ice cream cone was invented at the St. Louis Worlds Fair by Ernest Hamwi in 1904. His waffle booth was next to an ice cream vendor who ran short of dishes. Hamwi rolled a waffle to hold ice cream and the cone was born.
PatentStorm News
Make the Most of Our Site
See this month's Top Inventors and Most Cited Patents.
Stay on top of the latest innovations by subscribing to an RSS feed.
Registered users: Manage your profile.
| Number | Title | Issue Date |
| 7206952 | Digital wake-up signal from switch transition of two analog signals A digital wake-up signal is generated from an analog switch on a printed circuit board in which a ground trace and multiple conductive switch traces are bridged by a moveable contactor responsive to movement of an actuator. A resistor network is coupled to the switc... | 04/17/2007 |
| 7116157 | High output impedance current source A circuit for applications such as electrical impedance tomography includes a voltage-to-current converter having an input for receiving a voltage waveform and an output for outputting a current waveform to a load at an output resistance for the voltage-to-current c... | 10/03/2006 |
| 6949971 | Reference voltage generating circuit for outputting multi-level reference voltage using fuse trimming A reference voltage generating circuit includes voltage outputting means for outputting a reference voltage corresponding to a difference between a band gap reference voltage and an input voltage; a first resistor having one end that is coupled to the output of the ... | 09/27/2005 |
| 6570765 | Over-voltage protection for electronic circuits Over voltage protection is provided for electronic circuits by disposing one or more ground bars for diverting harmful currents away from the sensitive electronic circuit elements. The ground bars are each associated with a row of contact portions of the ... | 05/27/2003 |
| 6079401 | Single knob rotary oven control apparatus providing continuous and discrete control information In an appliance such as an oven for cooking food, the invention contemplates a user rotatable, single knob oven control device which provides both discrete and continuous control signals to the appliance controller. The discrete outputs indicate selection... | 06/27/2000 |
| 5658479 | Positive temperature coefficient thermistor heater and positive temperature coefficient thermistor heater device using the same The positive temperature coefficient thermistor heater is composed of a positive temperature coefficient thermistor element, and electrodes formed on the both principal faces of the thermistor element. At least one of the electrodes consists of split elec... | 08/19/1997 |
| 5453728 | Rheostatic device in a switching arrangement for electric tools An electric tool rheostatic device in a switching arrangement is provided for regulating the speed of an electric motor in an electric tool. A circuit board for receiving electronic components is disposed in a switch housing. A potentiometer disposed with... | 09/26/1995 |
| 5319345 | Variable resistor A variable resistor is provided with a series resistor network including first, second and third resistor parts which are connected in series, where the second resistor part is connected to the first and third resistor parts via first and second nodes, re... | 06/07/1994 |
| 5144278 | Variable impedance device and circuit for sensing adjustment thereof A circuit and apparatus for sensing the adjustment of a variable impedance device includes an elongated switching element having an alternating series of conductive and non-conductive areas. The conductive areas are electrically connected. As the device i... | 09/01/1992 |
| 4812804 | Controller for electric devices directed to use in bath Disclosed is a novel controller for electric devices directed to use in bath, comprising a moisture- and waterproof container that encloses the main part of an electric device; a magnet movably provided outside the container; a switch means provided insid... | 03/14/1989 |
| 4684881 | Low impedance switched attenuator A switched attenuator circuit providing three selectable voltage-divider ratios including one which passes substantially 100 percent of the input signal. The circuit places constant load resistance on its source in all positions when driving a high-resist... | 08/04/1987 |
| 4314666 | Adjustable electronic temperature control, especially for refrigerators or the like Adjustable electronic temperature control, having a bridge circuit with arms and at least one diagonal connected between points of the bridge, a thermistor for sensing temperature connected in one of the arms, a control circuit to be activated by the temp... | 02/09/1982 |
| 4151401 | PTC heating device having selectively variable temperature levels A controllable electric heating device uses a PTC resistance body having first areal electrode on one surface and two spaced apart areal electrodes of different areal size on the opposite surface in overlapping relation with a part of the first electrode ... | 04/24/1979 |
| 4109231 | Portable switch and dimmer control console A portable switch and dimmer control console for conveniently controlling a plurality of electrical devices and variably controlling the intensity of at least one fixture in a single conveniently designed self-contained portable unit.... | 08/22/1978 |
