| 摘要 |
655,193. Multiplex pulse signalling. PHILIPS ELECTRICAL, Ltd. March 2, 1948, No. 6553. Convention date, March 5, 1947. Drawings to Specification. [Class 40 (v)] In a multiplex phase or duration modulated pulse signalling system, saw-tooth voltages for modulating and for demodulating are obtained by integrating the channel gating pulses at the transmitter and at the receiver, respectively. At the transmitter, Fig. 1 (not shown), a cycle synchronizing pulse controls a chain of successively operating gating pulse generators, each controlling a channel amplifier. One channel is used for synchronizing pulses. In each of the other channels, the variable amplitude signal pulses are mixed with the integrated gating pulses of the particular channel to produce phase-modulated pulses. At the receiver, (Fig. 2 (not shown), the synchronizing pulses are separated by integration and used to control a chain of successively operating gating pulse generators. The gating pulses control demodulators of the type described in Specification 631,171, in which signal pulses are applied to the control grid of a secondary emission valve and a mixing voltage derived from the channel gating pulse by integration is applied to the anode, the demodulated output being taken from the secondary anode. Specification 600,291 and U.S.A. Specification 2,284,444, also are referred to. |
