953,594. Semi-conductor pulse circuits. PHILIPS ELECTRICAL INDUSTRIES Ltd. Oct. 6, 1961 [Oct. 11, 1960], No. 36025/61. Heading H3T. [Also in Division G4] A counter constructed from photoconductive and electroluminescent devices is shown in Fig. 3. The counter is primed by closing switch S, whereupon a flash of light from lamp NI illuminates photoconductor 20 and electroluminescent device 21 is energized from terminals 18, device 21 creating a holding circuit for itself by illuminating a photoconductor 22. Device 21 also primes the first stage of the counter proper by illuminating photoconductor 24. A pulse applied to terminals 38 energizes an electroluminescent strip 19 which is common to all stages of the counter, and device 25 is then energized through a further photoconductor 40 associated with strip 19. Device 25 creates a holding circuit for itself through photoconductor 26, extinguishes device 21 by creating a shunt path through a photoconductor 23, and primes the next stage 29 by illuminating photoconductor 28. The following stages operate in a similar manner. The counter may be used to control a stepvoltage generator, Fig. 1, forming a balancing voltage source in an analogue-to-digital converter. The unknown voltage is applied at X, and devices 23, 25, 29 . . . of Fig. 3 are represented in Fig. 1 by light sources L 0 -L 9 . Initially L 0 is energized and photoconductor R 0 supplies a balancing voltage of 0.1 volts from a 1-volt source B 1 . Assuming an input at X of 0.86 volts, difference amplifier M energizes a lamp A1 which in turn controls a relaxation oscillator, Fig. 2 (not shown) supplying pulses to terminals 38, Fig. 3. Sources L 0 -L 8 are energized in sequence by the counter to produce an increasing step voltage until the input X is exceeded. Amplifier M then extinguishes A1 and lights A2, the latter controlling a further pulse source and counter including electroluminescent devices L 0 1-L 9 1. Devices L 9 1- L 6 1 are energized in turn to reduce the balancing voltage in steps of 0.01 volts until equality is attained.

819,494. Etectric indicating systems. KELVIN & HUGHES Ltd. July 26, 1957 [Aug. 8, 1956], No. 24330/56. Addition to 788,544. Class 40 (1). Apparatus for measuring the rotation of a compass magnet 11 relative to a craft on which it is mounted comprises a semi-conductor crystal 10 mounted coaxially with the magnet and in its magnetic field, fed with A.C. along its horizontal axis 12, 13 so that any angular displacement of this axis relative to the horizontal axis of the magnet produces a P.D. across the vertical axis 17, 18 by the Hall effect, which is fed to a motor 22 to realign the axes of the crystal 10 and the magnet 11. The rotation may be telemetered via a known transmitter 26 to remote receivers.

818,065. Semi-conductor devices. SIEMENSSCHUCKERTWERKE A.G. Nov. 24, 1955 [Nov. 26, 1954], No. 33722/55. Class 37. A Hall effect device comprises a semi-conductor member with asymmetrical Hall electrodes such that a voltage appears between these electrodes when primary current is flowing but no magnetic field is applied, and means for applying a magnetic field of such magnitude that the Hall potential is reduced to zero or doubled, depending upon the direction of the field. The device may be utilized in switching, control or measuring circuits. Fig. 2 shows a semi-conductor body 1 having primary electrodes 2 and 3, and asymmetrical Hall electrodes 4 and 5 the output from which is applied to a measuring instrument 6. Fig. 3 shows an arrangement comprising three Hall electrodes the initial voltage between electrodes 14 and 15, and 16 and 14 being arranged to be zero and doubled respectively or vice versa according to whether the magnetic field is applied in one or the opposite direction. The magnetic field can thus be used to switch the output to either of electrodes 15 and 16. Other arrangements are described involving more than three Hall electrodes at least two of which are positioned asymmetrically, for switching or control purposes. The relative position of one or more of the electrodes may be made adjustable. The semi-conductor material may consist of Am Bv compounds such as In Sb or In As. Specifications 719,873, 763,348, 797,505 and 802,687 are referred to,

Equipment for measuring distribution of void or particle size capable of measuring the size of a void or a particle in a short time with high accuracy. When the size of a void Y existing in a porous insulator film (3) or the size of a particle in a thin film is measured, a sample (5) having the insulator film (3) formed on the surface of a substrate (4) is irradiated, from the surface side thereof, with X-rays R at a specified incident angle thetai larger than the total reflection critical angle of the insulator film (3) but not exceeding 1.3 times the total reflection critical angle of the substrate (4). X-rays beamed into the insulator film (3) and reflected off the surface of the substrate (4) and not entering the void Y but exiting the insulator film (3) are a scattering component and such a scattering component as having a larger exit angle as compared with that when the reflecting component does not enter the void Y but exits the insulator film (3) is detected. La présente invention concerne un équipement pour mesurer la distribution de la taille des vides ou des particules, capable de mesurer la taille d'un vide ou d'une particule en un temps très court, avec une haute précision. Pour mesurer la taille d'un vide (Y) existant dans un film isolant poreux (3) ou la taille d'une particule dans un film mince, on prend un échantillon (5) constitué d'un substrat (4) à la surface duquel se trouve le film isolant (3), et on le soumet depuis sa surface à un rayonnement aux rayons X (r) selon un angle d'incidence theta i supérieur à l'angle critique de réflexion totale du film isolant (3) sans toutefois dépasser de 1,3 fois l'angle critique de réflexion totale du substrat (4). Les rayons X envoyés sur le film isolant (3) et renvoyés par la surface du substrat (4) sans entrer dans le vide (Y) mais ressortant du film isolant (3) sont une composante de dispersion. En l'occurrence, la détection porte sur une telle composante de dispersion dont l'angle de sortie est supérieur à ce qui se produit lorsque la composante se réfléchissant ne pénètre pas dans le vide (Y) mais sort du film isolant (3).

1,119,708. Transistor amplifying and oscillating circuits; remote control of radio receivers. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 15 Oct., 1965 [15 Oct., 1964; 13 Feb., 1965], No. 43799/65. Headings H3Q and H3T. An R.C. coupled transistor circuit which can be adjusted to act as either a high Q circuit or alternatively as an oscillator comprises a first transistor T 1 with its collector connected to the base of a second transistor T 2 . A phase-shifting feedback loop is provided between a further electrode of the second transistor and one of the first transistor, e.g. the network C, R 1 , R 2 connected between the emitters; the arrangement is characterized in that the collector circuit of the first transistor T 1 includes at least two semi-conductor diodes D 1 , D 2 connected in series and arranged in the same direction of conduction as transistor T 1 . The collector circuit also comprises phase-shifting elements, e.g. capacitor C 5 such as to cause a phase-shift equal to but of opposite sign to that of the feedback network at the resonance frequency of the circuit, which is also arranged so that at that frequency the loop gain is substantially equal to unity. The Specification gives mathematical expressions for the necessary conditions, which comprise the inclusion in the collector circuit of transistor T 1 of series resistor R 5 of value double the emitter input resistance of transistor T 2 : each of the diodes D 1 , D 2 should have the same value of differential resistance as the emitter input resistance of transistor T 1 , and this can be varied so as to change the resonance frequency of the circuit by adjustment of the emitter-collector current, by means of resistor R 1 . The value of capacitor C 5 determines the effective Q of the circuit; it is approximately half C, lesser values making Q negative, i.e. causing sustained oscillations to occur. The Specification describes numerous modifications to the circuit, including means for maintaining the resonance frequency constant despite temperature variations (Figs. 3-5, not shown) and the use of transistors to replace resistors R 1 , R 2 (Figs. 6 et seq., not shown); transistor T 2 may also be replaced by a Darling- ton pair (Fig. 6, not shown) and resistor R 5 by diodes (Fig. 7, not shown). Two such resonant circuits may be tuned simultaneously by means of a single variable resistor (Fig. 8, not shown) and may be adjusted so that their resonant frequencies differ by a constant frequency, thus providing gang-tuned input and oscillator circuits for a superheterodyne receiver. In alternative circuits the feedback loop is located between the collector of the second transistor and the base of the first (Figs. 9-13, not shown) and in these the phase-shift may be shared between two stages (Fig. 11, not shown). Transistors of different conductivity type may be employed (Fig. 13, not shown). The Specification also discloses the manner in which two such resonant circuits may be coupled together (Figs. 14, 15, not shown) and the use of a shunt diode in the coupling network to act as a variable impedance for the purpose of gain control (Fig. 17, not shown). The arrangement may be modified by the inclusion of resistance in series with the capacitance C 5 to compensate at high frequencies for the effect of the capacitance between emitter and base (Fig. 16, not shown). When the arrangement is used as local oscillator in a superheterodyne receiver, the frequency may be automatically controlled by a voltage depending on the detected signal; again, the resistor R 1 may be of light-dependent type and controlled, e.g., from a remote light source. In another, e.g. remote control circuit, a single variable resistor may be used to tune over a number of separate desired wavebands, intervening frequencies being excluded by providing gaps in the resistor track which are closed by means of fixed resistors (Fig. 18, not shown). The arrangement may also be used as an amplifier of the modulation type; e.g. a capacitance pick-up may be connected in shunt with capacitor C 5 to vary the circuit Q, i.e. provide amplitude modulation, or resistor R 1 may be varied as a function of the signal, to provide oscillations modulated in frequency and amplitude. In an alternative embodiment, a small part of the current flowing through resistor R 1 is diverted from transistor T 1 , through a signalcontrolled transistor T 5 (Fig. 19, not shown) and flows direct into the diodes D 1 , D 2 . The Specification also discloses modifications of the circuit in which the resistance R 5 is considerably increased in value, to reduce the effect of non- linearity in diodes D 1 , D 2 with appreciable signal amplitudes, resistance being connected in series with capacitor C in compensation (Figs. 20-22, not shown). In an arrangement for providing a high Q circuit of improved stability, a second similar circuit, adjusted just to oscillate, is also provided its output being detected and supplied as a Q control to both circuits.

952,985. Semi-conductor devices. TELEFUNKEN A.G. April 8, 1960 [April 8, 1959], No. 12491/60. Heading H1K. In a transistor, the base zone includes particles (e.g. copper atoms) in a concentration such that the rate of recombination of charge carriers is a maximum adjacent either the emitter or the collector zone and reduces to a minimum adjacent the other of said zones. The Figure shows a device comprising base zone 1, emitter zone 2 and collector zone 3. A recombination layer 4 is provided adjacent the emitter which has the effect of reducing the grounded emitter current amplification factor # to improve the operating cut-off frequency. Alternatively the recombination layer could be adjacent the collector to prevent overloading and prevent storage effects. The recombination layer may be provided by diffusion of copper or nickel atoms.

PURPOSE:To increase the fetch angle and collecting stereoscopic angle of an X-ray in the state for horizontally holding a specimen in a scanning electron microscope by forming annular non-dispersion type detector and disposing it in the vicinity of an electron beam/route so that electron beam passes inside the detector. CONSTITUTION:Non-dispersion type X-ray detector 19 is formed annularly and disposed in the vicinity of electron beam route so that the beam passes inside the detector 19. A detector retaining plate 14 thermally integrally formed with an external cooling tank 15 is disposed, for example, between a specimen 12 in a specimen chamber 10 under an objective lens 6 and a magnetic pole 8 under the lens, and an annular semiconductor X-ray detecting element 19 of Si or the like deposited with Be thin film on the detecting surface thereof is buried on the back surface of the edge in a hole 18 for passing the electron beam as formed at the plate 14. Thus, the X-ray can be detected at an X-ray fetch angle near 90 deg. in narrow space without necessity of inclining the specimen 12, and X-ray collecting stereoscopic angle is increased to enhance the detecting sensitivity of an electron microscope.

1,070,878. Semi-conductor circuits. TEKTRONIX Inc. Jan. 7, 1966 [Jan. 19, 1965], No. 893/66. Heading H3T. In a pulse delaying circuit, particularly for use in a sampling oscilloscope, a ramp waveform 60 is generated by charging a capacitor 36 which is normally clamped by a gating transistor 18 having an anti-saturation circuit. Trigger pulses are derived at 48 from the Y deflection waveform at 46 and are differentiated at 50 before being used to trigger two tunnel diode bi-stable circuits 54, 26. The output from tunnel diode 26 turns off gating transistor 18 and allows capacitor 36 to charge via a constant current transistor 10 so as to provide a ramp waveform 60. When the ramp voltage 60 exceeds that of a staircase waveform from 64, comparator diode 62 becomes conductive, triggering a further bi-stable tunnel diode 68 the output from which is differentiated at 72 to provide a pulse at 82 which may trigger an avalanche transistor sampling circuit. The constant current via transistor 10 is arranged to arm the tunnel diode 68 so as to improve its triggering stability. The response of the gating transistor 18 is improved by an anti-saturation circuit 40, 28. The circuit is reset after a time, adjustable by switches 38, 86, by a monostable multivibrator 84. The comparison of waveforms 60 and 64 enables different portions of the vertical input signal waveform to be sampled at successive times. The sampled signals are stored and displayed as a lower frequency waveform on a cathode-ray oscilloscope.