摘要:
The oscillator includes a two-terminal device (1) as an active element and an impedance-matching network (4) for matching the two-terminal device to a load (A). The impedance-matching network is formed by a coupler (4) having four terminals (2, 3, 7, 8) two of which (7, 8) are terminated with impedances (5, 6) whose values are chosen depending on the output power or frequency to be adjusted or are varied as desired. Another of the terminals is connected to the active two-terminal device (1), and the fourth terminal (3) is the oscillator output.
摘要:
A design of magnetic field actuated sealed electrical contact unit for an electrically operated relay or mechanically operated switch is constructed of metal and plastics laminae (1, 1a, 2, 2a, 5 and 5a) one of which incorporates a diaphragm 10 which functions both as moving contact and armature. In the case of a relay the electromagnetic energizing unit (3, 3a, 4 and 4a) may also be of laminar construction.
摘要:
A multichannel duplex radio system for cordless telephone in which digital information is sent between the two ends. The data is divided into blocks which are transmitted in a fraction of the original block length. The other time slots are used for the duplex return path and for other similar equipment operating nearby. A direct conversion radio receiver is used in which the local oscillator signal is modulated for transmission.
摘要:
As is well known, a virtually flicker-free picture is obtained by using a sufficiently high picture-reproducing frequency and doing without interlaced scanning. This is achieved with a suitable standard converter in which the picture is temporarily stored in digital form. By suitable multiplexing, the digital frame store (221, 222, 223) can also be used for the conversion of the text and graphics page. Multiplexer (26) and demultiplexer (27) are switched by a blanking signal (Blank, Blank') which is buffered in the frame store together with the associated picture section.
摘要:
A rod of silica 14 is inserted into a substrate tube 10 whose bore is lined with a layer 11 of material having a refractive index less than that of silica. This layer 11 is itself covered with a layer 12 of silica. The assembly of the rod and tube is drawn into fibre, or its components are fused together to form a solid cross-section optical fibre preform.
摘要:
A leakproof electromagnetic relay in which a pourable sealing compound is introduced into the interior of the lower housing of the relay. A recess is formed in at least one sidewall of the housing through which the sealing compound is poured. The compound distributes itself equally on the bottom of the housing and flows into the separating points or gaps of the housing by capillary action. A cover closes the recess after the compound has been poured in. The invention permits the relay to be sealed in its upright position and further processed.
摘要:
A method of synchronizing a digital radio pager receiver with incoming digital data signals. At switch-on the receiver first attains a "course" bit synch during the first quarter-word period and then a "fine" bit synch during the next half-word period. The receiver then examines incoming data bits to determine simultaneously (a) whether valid data is being received and (b) whether the incoming data contains a preamble sequence. If either determination is successful the incoming data is then examined to determine whether it contains a synchronizing word or an address word. The synchronization and address word determination is also carried out while bit synch is obtained and the valid data/preamble determination is effected.
摘要:
In the manufacture of display structures--including fluorescent material displays--by means of a print process, a base material (glass or plastic material), prior to the print process, is coated with an electrically conductive layer. During the print process, a strippable coating or pigmented lacquer having the shape of the structure, is deposited onto a first layer. After the print process, the non-printed electrically conductive layer is etched away and in the case of the non-fluorescent display structure, the strippable coating is peeled off the electrically conductive layer. The invention provides an improvement in the manufacture of display structures over the hitherto conventional photographic reproduction of silk-screen printing methods, and provides display structures having sharp edges to a thickness of approximately 10 .mu.m.
摘要:
A gain regulation circuit e.g. for a telephone subscriber's instrument, includes a plurality (2n+1) of long tailed transistor pairs one of which has a significantly higher gain than the remainder (2n). The circuit may be adjusted to a composite gain value between limits defined by the high and low gain pairs by providing a suitably weighted combination of these pairs. Typically, this weighting is achieved by control currents fed into the tail circuits of the pairs.
摘要:
Feedback equalization is employed for digital repeaters of transmission systems having twisted-wire pairs, in order to reduce intersymbol interference while minimizing near-end crosstalk gain. Previously the incoming signal was selectively amplified at the higher frequencies in order to negate intersymbol interference, with subsequent near-end crosstalk gain. According to the present invention the intersymbol interference element of an incoming signal is cancelled, prior to amplification in an adder by a compensation signal derived from the output signal of a regenerator and a retimer. An output stage serves to amplify and shape the resultant signal to a form suitable for transmission. The compensation signal comprises the inverted output of a filtering and scaling network.