An amplitude equalizer which adds the outputs of two circuit means having opposite characteristics, whereby a flat delay-frequency characteristic and powerful frequency-amplitude characteristic are obtained. Further, a variable amplitude equalizer including two of the same connected in parallel and a variable attenuator inserted in one of the parallel paths. Still further, an automatic amplitude equalizer wherein the variable attenuator is feedback controlled by an equalization residual. The amp...

A pressure equalizing cabinet for instruments intended to be submerged in water is described. The device includes a source of compressed air and a piston in a cylinder. One side of the piston is in communication with the interior of the cabinet and the other side is in communication with the ambient. The piston also mounts a needle valve at a port in a conduit between this source of compressed air and the cabinet interior. When the pressure in the ambient exceeds the internal pressure, the pisto...

A port for equalizing the pressure between crankcase compartments of a two-cycle internal combustion crankcase compression engine. In one form of the invention, the port is formed in a common web between the crankcase compartments. In another form of the invention, a pair of ports are located in a common reed block, each of the ports being in communication with one of the crankcase compartments.

An automatic adaptive equalizer inspects either the input or output signal to the equalizer and extracts a predetermined specific waveform from such signal, analyses the extracted specific waveform based upon predetermined inspection parameters, and then controls the characteristics of the equalizer based upon the results of the analysis, thereby optimizing the equalizer characteristics.

A frequency equalizer is provided for suitably correcting a frequency characteristic of a signal transmitted through a signal transmitting system such as a coaxial cable and the like. The frequency equalizer has a plurality of serially connected fundamental circuits in each of which an input signal is processed by a series circuit of a multiplying circuit and an amplifier having its own frequency characteristic to generate a first signal, the input signal is separately processed by an amplifier ...

A Viterbi equalizer can provide an accurate equalizing characteristic. This Viterbi equalizer comprises a synchronizing signal data detecting circuit for detecting a synchronizing signal data portion from a reception signal data series, a transmission line characteristic estimating circuit for modelling an impulse response between a transmitter and a receiver by comparing a synchronizing signal data detected by the synchronizing signal data detecting circuit with a reference signal, and a decodi...

A waveform equalizer includes: a data signal input terminal for receiving an input data signal which is the object of waveform equalization; a plurality of S/H circuits each connected to the data signal input terminal; a sampling control circuit for repeatedly bringing the plurality of S/H circuits, one by one, to a sampling operation state; a selection circuit for selecting outputs of a predetermined number of S/H circuits which are in a hold operation state, respectively, from among the plural...

The object of the present invention is to provide an automatic equalizer which can automatically equalize distortion including a precursor component with a small amount of calculation and a small circuit scale. The automatic equalizer includes a subtractor for calculating differences between a received signal and N estimated received signals and outputting N estimated error signals, a decision unit for outputting part of a transmission signal sequence corresponding to one of the N estimated erro...

An optical equalizer for a wavelength-multiplexed optical communication system where an optical signal composed of a plurality of signal lights with different wavelengths is transmitted through an optical transmission line. The optical equalizer having: an optical coupler which has first to third ports where the optical signal to be input to the first port is output from the second port and the optical signal to be input to the second port is output from the third port; a wavelength division mul...

An equaliser circuit arrangement for compensating for the frequency-dependent characteristics of a transmission line such as an untwisted pair, for lines of lengths up to, say, 125 meters and at data rates up to, say, 155MBits/sec., in which signals from the transmission line are applied by way of a unity gain path and a frequency-selective path including a first wide-band amplifier of variable gain to a summing node. The signals at the summing node may be further amplified by a second wide-band...