A check synchroniser for checking the synchronism between two alternating voltages comprises means for forming pulses corresponding to the frequency and phase of the two voltages to be synchronized, the width of the pulses depending upon the allowable frequency and phase error between the two voltages, the pulses representing the frequencies of the two voltages being wider than the pulses representing the phases of the two voltages, means for comparing the time coincidence between the pulses of ...

A synchronism discriminating circuit comprises a phase comparator supplied with a reference signal having a reference frequency and a reference phase and with an input signal of which a synchronism with respect to the reference signal is to be discriminated, for comparing the phase of the reference signal with the phase of the input signal and for producing an output signal responsive to a phase difference between the two signals, where the reference signal is made up of a series of pulses, and ...

Apparatus for synchronizing a decoder of convolution codes with a received stream of convolutional code data. Synchronization is achieved with respect to such problems as bit polarity inversion and incorrect boundaries of branch intervals by examining a number of trial message sequences. The trial message sequences are obtained by an algorithm suggested by Viterbi involving selection of one survivor sequence terminating in each data state of the code. When the decoder is synchronized with the re...

A circuit for synchronizing a local television synchronizing oscillator with a remote one has a second phase discriminator coupled to receive the local and remote synchronizing signals. It generates an output voltage that is applied to a varicap of an integrating circuit that receives the local sync signal so that the time constant varies with phase difference of the signals. A first phase discriminator receives the remote sync signal and the integrated local sync signal and applies a control vo...

A driving machine and a driven machine are to be kept in synchronism. Tachometer generators attached to both machines generate signals which charge a capacitor either positively or negatively with respect to a given reference, and should the charge on this capacitor increase above a certain level, a circuit breaker means opens the line connecting the armatures of the two machines.

A signal synchronism detecting circuit comprises a receiving circuit receiving a serial data including data bit groups each composed of a predetermined number of continuing bits and delimiter bit groups each composed of a predetermined number of continuing bits for delimiting the data bit groups from one another, a detecting circuit for obtaining an exclusive OR between continuing bits of the received serial data, so as to detect the delimiter bit group, and a serial-to-parallel converting circu...

A synchronism check relay includes both a high set and a low set slip cut-off circuit. The low slip cut-off setting is based upon the maximum slip frequency that can be tolerated and still allow reclosing. The high slip cut-off setting is a function of the maximum phase angle difference permissible between the voltages on the bus and line sides of the circuit breaker, and the time that the line is de-energized.

A synchronism detector circuit wherein it is arranged so that two a.c. voltages the synchronism of which is to be determined are converted, respectively, into rectangular pulses, which pulses trigger a pair of one-shot multivibrators, respectively, the logical product of the outputs from these one-shot multivibrators is provided, and the thus provided logical product causes signals indicating the states of synchronism between the a.c. voltages to be output.

The invention relates to a synchronism judgment apparatus for judging establishment of synchronization with a frame received as a sequence of consecutive slots to which sync patterns are dispersively distributed in a form commensurate with the receiving mode according to a standard suitable for one of a plurality of receiving modes, as well as to a communication system where such a synchronism judgment apparatus is employed. The synchronism judgment apparatus of the invention enables judgment of...

The invention provides a synchronism establishing method and apparatus including a plurality of modules having different independent synchronization patterns to be switched wherein the switching transition process having a time length corresponding to the number of protection stages necessary for pull in and protection of synchronism is reduced so small that the presence of such switching transition process can be ignored while assuring similar advantages to those of conventional synchronism est...