Abstract: The invention provides the ability to count symbols within drawings in an automated fashion using a computer processor. This may be accomplished by identifying a particular symbol (representing a drawing part) and then permitting the computer to search for the identified symbol in the drawing. Following the initial search, a secondary search may be performed to increase the accuracy of an initial automated count, and obtaining refined searches results representing similar parts (represented by the same symbol) but being a part type as indicated by an identifier associated with the initial symbol.

Abstract: The invention provides the ability to count symbols within drawings in an automated fashion using a computer processor. This may be accomplished by identifying a particular symbol (representing a drawing part) and then permitting the computer to search for the identified symbol in the drawing. Following the initial search, a secondary search may be performed to increase the accuracy of an initial automated count, and obtaining refined searches results representing similar parts (represented by the same symbol) but being a part type as indicated by an identifier associated with the initial symbol.

Abstract: The invention provides the ability to count symbols within drawings in an automated fashion using a computer processor. This may be accomplished by identifying a particular symbol (representing a drawing part) and then permitting the computer to search for the identified symbol in the drawing. Following the initial search, a secondary search may be performed to increase the accuracy of an initial automated count, and obtaining refined searches results representing similar parts (represented by the same symbol) but being a part type as indicated by an identifier associated with the initial symbol.

Abstract: A power supply for generating polarizing voltages for the drivers on an electrostatic speaker system includes a charging circuit which charges a battery from the applied audio signal. A dc-to-dc converter generates the relatively high polarizing voltages from the battery voltage and it includes an oscillator which generates an alternating voltage to a voltage multiplier circuit. An electronic switch circuit turns the oscillator on when an audio signal is present and turns it off a preselected time interval after the audio signal is removed.

Abstract: A quadraphonic headphone including an ambience control circuit which is contained within a hand sized case which is connected to the audio transducers in each headphone cup and which may be connected to a source of quadraphonic program material. The control circuit includes switches that allow the user to select the desired cross coupling of phase shifted audio signals between left and right primary audio transducers and left and right secondary audio tranducers, allows him to reverse the connections to any one of the audio transducers and allows him to sum the signals applied to the left or right audio transducers. The effect of this electronic mixing is enhanced by asymmetrically mounted the audio transducers within each headphone cup.

Abstract: A four-way electrostatic speaker system includes four step-up transformers which have their primary windings connected in a series-parallel circuit across an audio signal source. Electrostatic drivers connect to the secondary windings of each step-up transformer and each forms a parallel resonant circuit which is tuned to an audio frequency within the operating range of the electrostatic driver. The impedance reflected into the primary winding of each step-up transformer is such that the attached electrostatic driver predominantly receives frequencies within its operating range. The necessity of a separate crossover network is thus eliminated.