Radiative interconnection arrangement

Disclosed is an isolator switch or relay for isolating an electrical input and output. It comprises a pair of optical source-detector couples in which the sources are alternately overdriven over a low duty cycle to provide a rapid response. Input and output logic elements are connected to the couples, the former providing alternate time-spaced signals to the couples and the latter recovering the polarity of the input signal. Improved electromagnetic isolation between opposite sides of the couple as well as strobing and termination circuits are provided. The switch is adapted for use in all types of digital data communication circuits.

Photoelectric relay using optical couples

Fanfold paper is progressively withdrawn from the bottom of a container, fed past a printing mechanism, transported upwardly and deposited in fanfold configuration at the top of the container.

Fanfold paper transport

Apparatus for controlling the voltage on an electron tube element

A circuit arrangement for applying low frequency high voltage waveforms across a load and which includes low and high voltage circuits. The low voltage circuit includes a sinusoidal signal generator for producing a low voltage electrical waveform, and a transmitter circuit having first and second light emitting diode circuits by which first and second light signals are generated which are transmitted to the high voltage circuit by respective fibre optic light guides. The high voltage circuit includes first and second high voltage d.c. supplies and first and second triode valves. Grid modulation devices are associated with the first and second triode valves and are respectively responsive to the first and second light signals transmitted via the fibre optic light guides for varying the current through said first and second triode valves and the load in direct proportion to the positive and negative variations of said low voltage electrical waveform to thereby reproduce the positive and negative variations of the low voltage waveform at high voltage across the load.

Generation of low frequency, high voltages

Photoelectric modulator with transparent electrostatic shields

1,206,522. Chart recorders. LEEDS & NORTHRUP CO. 19 Feb., 1968 [3 March, 1967], No. 8035/68. Heading G4H. [Also in Divisions G1] In apparatus for recording a digital input signal on a strip chart in two analogue type records, the first record is derived from the output of a first digital-analogue converter to which are fed the most significant part of the digital signal and a digital signal of intermediate significance, the second record being derived from a second analogue/digital converter receiving the least significant part of the digital signal and the signal of intermediate significance. In the embodiment of Fig. 1 the two analogue/digital converters comprise resistors connected to transistors 22-64 the conductivity of which is controlled by the 1, 2, 2, 4 weighted output signals of digital register 1, the converters controlling a coarse and fine pen recorder 92. In the embodiment of Fig. 2 which is suitable for measuring frequency an additional transistor 245 and associated circuitry is included to fold the fine recorder scale about A060 instead of 0. This prevents the fine pen from crossing from one side of the strip chart to the other as the frequency fluctuates from slightly below to slightly above e.g. 60 cps. In a modification of the embodiment of Fig. 2 an additional increment of voltage is added in (to allow the fine recorder pen to continue to record increasing frequencies up to A099) under the control of either an electronic switch or a switch operated by the travel of the fine recorder pen. The outputs from the digital/analogue converters may be fed direct to electro mechanical or electronic modulators, the resulting A.C. signals being fed to transformers 310, 319 (Fig. 3) the secondary windings of which are connected via amplifiers 311, 320 to the fine and coarse pen motors 312, 321 respectively. Alternatively to prevent spurious changes in the digital input signal being recorded the signals from the converters may be applied to contacts 303, 316 of a relay 324, the relay being energized under the control of circuitry 330.

Norman E Polster

Papers

Photoelectric modulator with transparent electrostatic shields

Analog centesimal recorder having redundant digit

Digital analog recorder

Means for accumulating and displaying data

Analog decimal recorder with overlapping ranges