Abstract: A folded-cascode amplifier conventionally comprises an "input" transistor of a first conductivity type receiving input signals at its base electrode, an "output" transistor of a second conductivity type, complementary to the first, connected in common-base amplifier configuration with its base electrode connected to receive fixed bias potential, and a current source supplying the combined "input" transistor collector current and "output" transistor emitter current to an interconnection between the "input" transistor collector electrode and "output" transistor emitter electrode. In the folded-cascode amplifiers herein disclosed the base electrode of the "output" transistor has the input-signal-responsive emitter potential of the "input" transistor applied to it.

Abstract: The transient photo-currents generated in the collector-base junction of an amplifier transistor responsive to transient ionizing radiation are counteracted by those similarly generated in an auxiliary p-n semiconductor junction in inverse-parallel connection with the emitter base junction of the amplifier transistor. To provide more perfect counteraction of these photo-currents, this auxiliary semiconductor junction, operated in reverse-bias, is matched in characteristics with the collector-base junction of the amplifier transistor, and the base-to-collector potential of the amplifier transistor is arranged to be substantially the same as the reverse-bias potential across the auxiliary semiconductor junction.

Abstract: A digital gain control system is disclosed. A clock oscillator drives a counter which in turn provides an output to a D/A converter. The analog output of the converter is used to develop a signal for controlling the gain of a gain-controlled amplifier. In order to compensate for the nonlinear gain versus control current characteristic of the amplifier, additional circuitry is employed so that the initial increment in control current, that is, the increment that occurs as the counter goes from the 0000 to the 0001 state, is significantly greater than the remaining increments. In conjunction with volume control circuitry for audio amplifiers, this circuitry assures a muted condition in the 0000 state, and an audio output corresponding to at least the minimum discernible level in the 0001 state.

Abstract: A line scanning apparatus employing a multiplicity of linear arrays, the linear extent of which is less than the length of the scan line. To permit an entire line to be covered, the arrays are offset from one another in the direction of scan with adjoining array ends overlapped. To correct for the misalignment and redundancy introduced, the image data from the arrays is buffered until a line is completed when readout, is initiated. During readout, cross over from one array to the next is effected within the overlapped areas and the redundant data discarded.

Abstract: A line scanning apparatus employing a multiplicity of linear arrays, the linear extent of which is less than the length of the scan line. To permit an entire line to be covered, the arrays are offset from one another in the direction of scan with adjoining array ends overlapped. To correct for the misalignment and redundancy introduced, the image data from the arrays is buffered until a line is completed when readout, is initiated. During readout, cross over from one array to the next is effected within the overlapped areas and the redundant data discarded.

Abstract: A method and circuit for protecting the output stage of an amplifier from thermal overload. A normally-open, temperature sensitive switch is thermally coupled to the transistors in the output stage and electrically connected across a portion of the feedback resistance element of the amplifier, in one circuit embodiment. Whenever the temperature of the transistors reaches a predetermined threshold level, the switch closes and acts as a low resistance path across that portion of the feedback resistance element, thereby reducing the gain of the amplifier to a safe level which is zero in the preferred embodiment. Thereafter, when the temperature decreases below the predetermined threshold level, the switch automatically opens to restore normal operation of the amplifier.

Abstract: An apparatus for effecting automatic gain control comprises an attenuator employing pin junction diodes, a high-frequency amplifier employing a bipolar type automatic gain controlling transistor or a MOS-FET which is always supplied with automatic gain control signals, and switching means for selectively applying automatic gain control signals to the attenuator, thereby permitting increase of the gain control variable without deteriorating the noise factor and the cross modulation characteristic of the signal.

Abstract: Power limiting circuitry for use with a power amplifier, the power amplifier having (a) a power supply voltage source connected thereto and (b) a load impedance, the power limiting circuitry comprising detecting means for detecting the magnitude of the load impedance; and control means responsive to the detecting means for controlling the magnitude of the power supply voltage applied to the power amplifier; means for sensing the temperature at a predetermined point in the power amplifier and generating an output signal when the temperature exceeds a predetermined amount; and AND circuit means responsive to the detecting means and the temperature sensing means for actuating the control means in response thereto.

Abstract: A high-precision amplifier employs a feed-forward technique to provide a first order correction of amplifier distortion. A second amplifier is utilized to sense the base-to-emitter distortion of a main amplifier and develop an error output which is injected into an output node to provide cancellation of distortion from the output of the main amplifier. The feed-forward distortion-correction technique is particularly applicable to high-precision wideband differential amplifiers; however, the technique may be used in other amplifiers as well.

Abstract: A negative feedback operation of a PWM-type amplifier is stabilized by the use of a resistor. The input signal is voltage-compared with the triangular wave of a higher frequency than the input signal to form a PWM-signal, which is, in turn, power amplified and is provided to a load after demodulated by a low-pass-filter. A part of the output voltage is fed back from a common connection point of an inductor and a capacitor of an LC-filter forming the low-pass filter. A resistor is connected in series with the capacitor, and the negative feedback operation is, thereby, stabilized.

Abstract: A method and apparatus for detecting printing faults or errors in a sample of printed material, such as a bank note, by determining the relative positions of corresponding text on the sample and each of a number of original bank notes, each having been printed by a different printing process used in printing the sample combining the text of the originals optically or electronically taking into account the positions of the text in the originals relative to the text on the sample resulting from superimposition of the text produced by each of the printing process used to produce each original, and comparing the text of the sample with the total combined text. The relative positions of corresponding text on the sample and originals is determined by scanning the sample and originals and obtaining reflectances values at each of a number of corresponding raster points and correlating the corresponding reflectance values to obtaining the relative position values.

Abstract: The apparatus includes a photoelectric sensor associated with a predetermined zone of a hollow glass article to be examined for faults. During one testing operation, the photoelectric sensor successively detects all faults in that zone and generates for each a fault signal whose value is dependent upon the characteristics of the fault. The fault signals are applied to a threshold circuit which generates an output signal only when the fault-signal value exceeds a threshold-signal level. The setting-up procedure involves performing at least one preliminary testing operation upon a preselected sample or standard article having acceptable faults. Each threshold-circuit output signal automatically results in a circuit adjustment which reduces by a predetermined amount the extent to which the respective fault-signal value exceeds the threshold-signal level.

Abstract: The perforated strip is transported lengthwise along a predetermined transport path. The perforations have a width w and an inter-perforation spacing s as measured in the transport direction. The perforations are sensed at two predetermined sensing locations located along the transport path. The distance between the two sensing locations is equal to as .+-. bw, wherein a is equal to zero, unity or an integer greater than unity, and wherein b is a number greater than zero and less than unity. Sensing the perforations at sensing locations thusly spaced makes it possible to determine from the resultant signals the direction of strip transport.

Abstract: A compound transistor all of the first conductivity type circuitry having a high input impedance as well as a high gain, comprises a first, a second and a third bipolar transistor, and a fourth bipolar transistor complementary to at least the first transistor, the second and third transistors having their emitters coupled together to a first terminal and having their bases connected together and further connected to the collector of the fourth transistor, the bases of the first and fourth transistors being connected in common to a second terminal, the emitter of the first transistor being connected to the collector of the second transistor, the collector of the first transistor and the emitter of the fourth transistor being connected together to a third terminal.

Abstract: A phase-shifting circuit comprises a first transistor circuit having a base to which an input signal is applied, first and second resistors of equal resistance values connected mutually in series and between an emitter of the first transistor circuit and ground, a third resistor connected at one terminal thereof to the emitter of the first transistor circuit, a capacitor connected between the other terminal of the third resistor and ground, and a second transistor circuit having a base connected to said other terminal of the third resistor and an emitter connected to the junction between the first and second resistors, an output signal being led out from a collector of the second transistor circuit.

Abstract: Encoding photocells are positioned in a circuit array for sensing lighted and unlighted variations produced by changes in an optical code pattern. Corresponding signal output changes of the encloding photocells are detected by being sequentially connected to a sensing network including a reference photocell circuit array. The encoding photocell output changes are sensed at a voltage comparator having inputs connected to the sensing network and a fixed voltage reference to produce a binary signal output. A comparator inhibiting circuit deactivates the comparator in response to a malfunction condition to protect against erroneous operation.

Abstract: A voltage sensing circuit of differential input type includes at least one differential amplifier circuit connected between two complementary data lines of a semiconductor memory. The differential amplifier circuit detects data in response to a minute potential difference between the data lines and amplifies the same by a substantial change in conductance g.sub.m of metal oxide semiconductor field effect transistors (MOSFET) used in the circuit. When data is read from a semiconductor memory onto the data lines, the differential amplifier sensing circuit detects the data quickly by detecting potential changes of the data lines.

Abstract: A device for sensing the torque of a tape driving shaft transferred to a driven shaft, and indicating absence of tape to be driven. The shafts are resiliently coupled, and apertured opaque discs are coupled to the respective shafts. Radiation emitting and sensing elements on a movable bifurcated arm are held by the tape in alignment with the disc apertures to sense torque, and are moved clear of the discs if no tape is present.

Abstract: An optical scanning device scans recording tracks on a record carrier with the aid of a beam of radiation, while an objective, which concentrates the beam of radiation to a scanning spot, performs automatic electrically controlled movements in a direction perpendicular to the plane of the record carrier with the aid of a focussing bearing arrangement, so as to ensure a continuous focussing of the scanning spot on the recording tracks. Moreover, in order to follow the oscillations of the recording track, the objective also performs electrically controlled movements which are such that the scanning spot moves at least substantially parallel to the plane of the record carrier.

Abstract: A current mirror amplifier circuit with an input current path and an output current path is further provided with a sensing means responsive to the cessation of current flow in the output current path such that the cessation of current flow in the output current path causes the current flow in the input current path to be discontinued.