A compact and inexpensive variable resistor circuit has a value of resistance that can be set by a data signal. The variable resistor includes a number of variable individual resistances connected in series, and an electronic switch connected in parallel across each individual resistance. The values of the individual resistances are chosen to include a basic resistance value and a compensating resistance value, which corresponds to the impedance of the associated electronic switch in its closed ...

A first inverter circuit is coupled between a first voltage source and a reference potential by a plurality of cascaded transistors. Each of the cascaded transistors has a control gate which may be selected to bring the resistance of the transistor into circuit with the inverter circuit to control the charging rate of a distributed capacitance. An output circuit coupled to the first inverter circuit provides the distributed capacitance and an inverted buffered output. The output circuit also inc...

In a tampon comprising an absorptive relatively non-compressible core surrounded by a transmissive foam jacket, the foam jacket is formed into a skirt extending from the lower end of the core to define an opening to receive the finger of the user for digital insertion.

A digitally tuned active filter is disclosed. The filter is tunable by digitally controlling the variable conductance which comprises two resistors, one of which is in series with a field-effect transistor switch and those two in parallel with the other resistor. The field-effect transistor switch is switched by a digitally controlled variable duty cycle generator.

There is disclosed a current source for producing an output current the magnitude of which is controlled in a predetermined manner which comprises first and second constant current sources for supplying first and second currents, a current mirror circuit including first and second resistors through which the first and second current respectively flow, the current mirror circuit having an output to which a current amplifier is coupled and which provides the output current when rendered operative,...

An all digital equivalent to a voltage controlled oscillator with low intrinsic jitter and the absence of sample aliasing within a nonzero bandwidth, the offset (non-symmetrical) digitally controlled oscillator comprising a divider (divide by n or n-1) which is timed from a high speed reference clock, a 2.sup.m counter and a digital comparator. The divider divides the high speed reference clock signal so that for every thirty second cycle of the high speed reference clock a pulse is output from ...

A method for preserving a digitally signed document (160) in a digital data preservation system (10). A secure preservation request (176) combines the document (160) with a preservation signature (174) that is generated using an identification mark (172) and the document's associated digital signature (168). Once the document (160) is authenticated by the digital preservation system vendor, both the document (160) and the identification mark (172) are recorded onto preservation media (210) in hu...

A digitally controlled, manually actuated press comprising a housing having a lower platen attached thereto. The lower platen defines a generally planar top surface. Pivotally connected to the housing are left and right actuation handles, each of which is selectively movable between a loading/unloading and a press position. The press further comprises left and right transitional leveling members which are cooperatively engaged to respective ones of the actuation handles. Also included in the pre...

A system and method for compensating for a voltage offset between an inverting input and a noninverting input of an op amp to provide a stable bandgap reference. The method including measuring the voltage offset between the inverting input and the noninverting input of the op amp and searching for a compensating current input to the op amp that compensates for the voltage offset. A programmable current source is set to output the compensating current to the op amp.

An adaptive equalizer performs equalization at IF, demodulates the input signal and then generates the equalization coefficients at baseband from the demodulated data. Coefficient updating can be done on a non-real time basis and coefficients for individual bursts stored in a coefficient memory for retrieval when the same burst occurs in the next frame, thus obtaining a pseudo-continuous equalization for each burst. The error signal is derived from demodulated equalized data and correlated with ...