Abstract: A spectrum analyzer including a device for analyzing signals whose time duration is short as compared to the normal sampling rate of the spectrum analyzer. A transient signal, or a small portion of any analog signal, is sampled at a sampling rate which is substantially higher than the normal sampling rate of the spectrum analyzer, and the samples are stored in analog form in a storage device such as a charge coupled device acting as an analog delay line. The stores analog samples are then read out at the normal sampling rate of the spectrum analyzer, to form a longer duration signal which can be analyzed by the spectrum analyzer in a conventional manner.

Abstract: Apparatus for presetting an electric pulse counter to a given count without any action on its parallel input terminals and/or its parallel output terminals. The apparatus comprises a pulse generator which is connected, during a preset operation, to the count input of the counter through an electronic gate. The electronic gate is controlled by an auxiliary circuit. In one embodiment, the auxiliary circuit comprises as many voltage comparators as flip-flops in the counter. The voltage comparators enable the electronic gate as long as the states of the flip-flops are different from the desired states. In another embodiment, the auxiliary circuit mainly comprises a divider by N, N being the desired count. In a first step, the divider is reset and the counter is caused to count up to its maximum count and to deliver an overflow pulse when it resets. In a second step starting with the overflow pulse, both counter and divider count up from zero and the electronic gate is closed when the divider reaches the N-count.

Abstract: A symmetrical non-linear network for use in a function generator in which one or other of a pair of transistors is brought progressively into conduction by a non-linear network, so as to present a low dynamic resistance between the terminals. The non-linear network preferably includes a pair of diodes having a lower turn on voltage than that of the associated transistors, for example Schottky diodes with silicon transistors.The invention also provides a function generator incorporating the above non-linear network for converting square waves to sine waves in which the amplitude of the input signal to the network is controlled automatically.

Abstract: Digital calculating apparatus, which is particularly suitable for linearizing a digitized output signal produced by a non-linear transducer such as a thermocouple, comprises a store connected in a recirculating loop including combined adder and subtractor circuit, means for changing a number entered in the store to a predetermined target value by a linear or an exponential progression involving groups of N adding or subtracting-cycles, means for counting and storing the numbers of groups of cycles required to achieve the target value, and means for entering another number in the store and subjecting it to the same numbers of groups of M adding or substracting cycles, where M .ltoreq. N, to produce the required answer. For linearizing the digitized output signal x from a thermocouple, where x is given by T = a.sub.o + a.sub.1 x + a.sub.2 x.sup.2 + . . . ta.sub.n x.sup.

Abstract: Disclosed is a method of and an apparatus for measuring the thickness of an object, usually a metal strip, by using a radiation beam and digital techniques and, more generally, a method of linearization of an exponential function which can be advantageously implemented by digital techniques. First, a counter is preset to a count corresponding to a predetermined magnitude of a value to be linearized. Then, a sequence of pulses whose number is representative of the value to be linearized is generated. The pulses of this sequence are counted so as to generate a signal each time the number of pulses counted corresponds to a standard value unit. Each signal so generated is used to modify by a predetermined count the count of the preset counter whereby, at the end of the sequence, the contents of the preset counter is representative of the value to be linearized.

Abstract: The analogue to digital converter is of the bipolar mark-space type and includes an integrator for integrating the analogue input signal to be converted. A square wave generator is connected to the input of the integrator so as to superimpose a triangular periodic signal on the output signal produced by the integrator.First and second level detectors are connected to compare the output signal from the integrator with first and second detector levels respectively to produce first and second control signals respectively when the magnitude of the output signal from the integrator exceeds the first level and falls below the second level respectively. Switch means responsive to the first and second control signals are provided to respectively apply first and second reference signals. The conversion interval is set equal in duration to the duration of an integral number of cycles of the periodic triangular signal.

Abstract: A ramp type analogue to digital converter including an integrating circuit the output of which is first set to a level dependent upon the magnitude of an analogue input voltage to be converted. A reference signal is then applied to ramp down the integrator output level to a datum level and the conversion is effected by counting clock pulses while the integrator output is ramping down to datum level. The magnitude of the reference signal and the numerical weighting of the clock pulses being counted are scaled down by a common factor when the ramp reaches a value close to the datum level so that the slope of the ram is reduced and the resolution of conversion is increased as it approaches datum. Thus, compared with a ramp type digital voltmeter having a constant slope discharge ramp and a given resolution, the discharge time is reduced for the same resolution of conversions.