Abstract: A tweezer probe comprises a pair of arms (10) each made of a multi-layer printed circuit board. The outer conductive layers (20,32) on each arm are etched to form a shield region (36) and a tip contact (34). The tip contacts (34) are connected to inner conductive layers (24,28) by through-hole plating, the inner layers being etched to form connector wires (40) extending along the length of the arms to a connector region where leads (8) are attached. The arms (10) are substantially rigidly mounted together, with an adjustment mechanism (14,72,74,76) being provided to alter the angle between the arms, the tips being moveable towards each other against the bias provided by the inherent resilience of the arms.

Abstract: A multichannel sine synthesizer for the primary signal production in measuring signal generators having a phase accumulator (11), a low-pass filter (12), an interposed first synthesis channel (13) and a clock control unit (25) which together convert a phase increment applied to the phase accumulator (11) into a sinusoidal signal. A problem in such synthesizers is the comparatively low maximum frequency of the sinusoidal signal produced because this frequency is limited by alias frequency effects. This is the reason why, in order to increase the maximum frequency with the same clock frequency, there is connected parallel to the synthesis channel (13) at least one further modified synthesis channel (26), which operates so as to be shifted in the time and to the input side of which is applied an additive phase value constant with a given frequency.

Abstract: An inexpensive potentiometer circuit having an approximately logarithmic characteristic that can be accurately determined is obtained if a resistance element having a linearly adjustable ohmic resistance value is connected parallel to a negative impedance converter (1) having an output port connected to a fixed ohmic resistor (8).