摘要:
A circuit for producing a frequency dependent output signal in response to two a.c. input signals, including a converter unit connected to receive the two a.c. input signals for furnishing an output signal having a d.c. component which varies in dependence on changes in the value of a relationship between the frequencies of the two a.c. input signals, and a frequency generator connected to the converter unit for producing an a.c. output signal whose frequency is a function of the value of such d.c. component.
摘要:
In a tuning circuit for tuning a receiver to a desired broadcast frequency, which tuning circuit includes a source of counting pulses indicating the magnitude of the change in the frequency value to which the circuit is to be tuned, a counter connected to receive the counting pulses and to assume a count state representative of the broadcast frequency to which the circuit is to be tuned, and a timing member for producing a tuning signal having a value determinative of the frequency to which the circuit is tuned during a tuning operation, the timing member is provided with a unit connected to the source of counting pulses for deriving a control signal representative of the frequency of the pulses, and a unit connected for varying the tuning signal in accordance with the control signal in such a manner that as the frequency of the counting pulses increases, the rate of change of the frequency to which the circuit is tuned is increased.
摘要:
In a circuit system for the generation of a direct control voltage dependent upon an alternating voltage for a dynamic compander device, the system including a charging capacitor, a charging circuit connected to charge the capacitor, and a circuit connected to discharge the capacitor, a comparator unit is connected to effect comparison between the alternating voltage and a reference voltage and to produce an output voltage representative of the amount by which the alternating voltage exceeds the reference voltage, and at least one of the circuits is formed of a current source and an electronically controllable current path connected between the source and the capacitor and having a control input connected to the comparator unit for varying the conductance of the current path as a function of the output voltage of the comparator unit.
摘要:
Digital information transmission system components including at least one unit arranged to transmit signal elements in parallel, at least one unit arranged to receive signal elements in parallel, and a corresponding plurality of signal transmission paths connected between such units to each convey a respective one of the signal elements, in which a unit serving to transmit such signal elements is constructed for selectively creating, in each path, a signal element in the form of a signal state representing either one of two binary values or a signal state different from that representing either such binary value; and a unit serving to receive such signals is constructed for producing a response which distinguishes between the appearance, in each path, of either binary value state or the different state.
摘要:
In a microwave circuit for a parametric upper sideband down converter with real image frequency termination conductance, including a pump circuit supplying a pump signal, a parallel circuit at its input, an intermediate frequency circuit at its output, and a reactance diode coupling the parallel circuit and intermediate frequency circuit together, the parallel circuit is tuned approximately to the frequency of the pump signal; the intermediate frequency circuit is composed of a .pi. filter having a series branch containing a first inductance connected in series between the diode and the output of the microwave circuit, a first shunt branch located between the diode and the inductance and containing a first capacitance and a second shunt branch located between the inductance and the output of the microwave circuit and containing a second capacitance; the microwave circuit further includes a second inductance connected in series with the reactance diode; and the portion of the microwave circuit constituted by the diode, the second inductance and the first capacitance forms a resonant circuit tuned to the frequency of the pump signal.
摘要:
A measuring sensor having a temperature-dependent conductivity and composed of a shaped body of a solid electrolyte material exhibiting such temperature-dependent conductivity, and two contact layers sintered onto the body and arranged for connection to circuit conductors.
摘要:
In a superheterodyne signal receiver including an input circuit arranged to be tuned to a frequency to be received and including a signal controllable variable reactance element presenting a reactance whose value is adjusted by a tuning signal and determines the frequency to which the input circuit is tuned, and a controllable local oscillator producing an alternating signal to be mixed with a received signal to produce an intermediate frequency received signal, a tracking circuit composed of: a first frequency control circuit including the local oscillator; a second frequency control circuit including a controllable sampling oscillator and a member connected to respond to the frequency of the output from the sampling oscillator to derive a signal related thereto and supplying that signal, as the tuning signal, to the controllable element; and a control signal generating unit generating first and second control signals and connected for supplying the first control signal to the first frequency control circuit for adjusting the frequency of the signal produced by the local oscillator, and for supplying the second control signal to the second frequency control circuit for adjusting the value of the tuning signal to tune the input circuit to a selected frequency, the generating unit maintaining a relationship between the first and second control signals such that the output frequency of the local oscillator is adjusted to the value corresponding to the received signal frequency to which the input circuit is tuned.
摘要:
Circuit for automatic dynamic compression an/or expansion. The circuit has adjusting member (10) for varying the propagation constant in a useful signal path and a further similar adjusting member (30) for varying the propagation constant in a branch path which serves for deriving a control voltage which is applied to the control inputs (11,31) of the adjusting members (10,30) in the useful signal path and in the branch path. Further the circuit has a lowpass circuit (20 . . . 26) which is connected to the adjusting member (10) located in the useful signal path. The circuit can be changed over to a different compander characteristic when the adjusting member (10) located in the useful signal path is connected up as a controllable highpass (10,15). The limiting frequency is of the order of magnitude of the limiting frequency of the lowpass circuit (20 . . . 26). The highpass can be formed by a capacitor (15) in series with the adjusting member (10) in the useful signal path and the highpass function for low frequencies can be limited by a resistor (12) in parallel with the adjusting member (10) and the capacitor (15). The limiting frequency of the lowpass circuit (20 . . . 26) is reduced by an additional capacitor (27) in parallel with the capacitor (26) already provided. In both operation modes, the same voltage generator (30 . . . 36) is used for controlling the adjusting member (10) in the useful signal path.
摘要:
Plastic surfaces are activated for the reception of adherent metal coatings by depositing noble metal nuclei thereon, the noble metal nuclei being deposited by a multistep process including the steps of mechanically roughening the surface, treating the roughened surface with a complex-former solution, thereafter treating the surface with a solution of a noble metal complex salt so as to exchange the noble metal complex for the complex deposited by the initial complex-former solution, and converting the noble metal complex to form metal nuclei.
摘要:
A solar cell arrangement comprises a first plate or disc of light transmissive material, one side of the first plate or disc having a structure of light transmissive elevations tapering parabolically and cut off parallel to the surface of the plate or disc at the level of their focal points or lines, the structure having a layer of at least partially light transmissive electrically conductive material on the surface of the elevations and a second plate or disc of semiconductor or metallically conducting material, the plate or discs being assembled together to provide photo voltaic and electical contacts between the said cut off surfaces, of one plate or disc and the surface of the other plate or disc such that light passing through the first plate is concentrated at the contacts.