A battery-powered hand-held programmable calculator for performing arithmetic, trigonometric and logarithmic functions and displaying the results thereof is provided with the capability of being fully programmable including branching based on data value. Absolute line number addressing is provided. Program line numbers and the key code associated with an executable step are displayed. The top of the programmable memory is configured as a nonexecutable line corresponding to an automatic stop and ...

A display having variable resolution includes a plurality of discrete light emitting elements arranged in an array. Intervals between elements are quantized into a plurality of levels representing information to be displayed. Selected light emitting elements disposed about the levels are energized by a signal having a duty cycle varied in response to displayable information having a magnitude within a particular one of the plurality of levels.

A method for statistically calibrating an analog-to-digital converter with an electronic test system. A digital-to-analog converter which has been calibrated by premeasured weighting coefficients with respect to two-state orthogonal signals is excited with two state signals at each input bit which together represent a single signal with uniform amplitude probability with respect to time, and wherein each excitation signal is orthogonal with respect to all other excitation signals. The output of ...

A radiation curable barrier coating having chemical resistance to many solvents, flexibility when cured, selective gloss and excellent abrasion resistance at a coating thickness provided by lithographic printing methods comprises acrylated melamine resin in combination with silica fillers and photoinitiators.

A charge-splitting device and method include a plurality of charge cells coupled to receive a charge in response to being simultaneously clocked into a charge receiving state by an applied clock signal. The received charge is split into predetermined charge portions among the plurality of charge cells in proportions dependent upon the total number of cells, their relative capacitance and the magnitude and timing of the applied clock signal. The charge portions are again split and selectively sum...

A device for measuring sheet resistivity of semiconductor materials and diffused layers uses a linear four-point probe having pneumatically-actuated contact pins coupled to a self-zeroing voltage amplifier and a current source having extremely high output resistance.

A flat-band voltage reference includes two insulated-gate field-effect transistors, hereinafter IGFETs, which are substantially identical except for their flat-band voltage characteristics and which are biased to carry equal drain currents at equal drain voltages. The resulting difference in potential between the gate contacts of the IGFETs produces a voltage reference which is substantially independent of variances in operating points, supply potentials, and temperature.

A measurement averaging counting apparatus employing a randomly phase modulated time base provides resolution improvement when measuring an applied signal comprising time intervals or pulsed frequencies repetitively occurring at rates synchronous to a counter's clock frequency. The phase of a reference frequency is varied in response to a random signal. The phase modulated reference frequency is applied to a frequency multiplier chain which multiplies both the frequency and the effective amount ...

This method and apparatus measures conversion of amplitude modulation to phase modulation and is useful for any application wherein resultant unwanted phase modulation is to be measured, but is mainly intended for testing devices used in frequency modulated multichannel communication systems having amplitude modulation to phase modulation conversion which causes distortion of a desired frequency modulated signal.

A light emitting diode is driven by an input signal and electromagnetically coupled to a photodiode. The photodiode is connected to a high impedance load across which is obtained a signal linearly related to but electrically isolated from the input signal.