SU1356243A1 - Stationary receiving device for inductive communication system - Google Patents

Abstract

The invention can be used to transmit information on the premises of manufacturing plants and provides enhanced noise immunity. The device contains receiver 1, loudspeaker 2, power supply unit 3 in the form of a power transformer 4, adder 5, switches 6.7, buffer blocks (WB) 8, 9, attenuators 10, 11, block 12 amplitude-phase correction and receiving antenna 13. The signal from the communication channel, which arrives at the receiving antenna 13, is reproduced by loudspeaker 2. To eliminate the effect of the power networks of the enterprise, which appear in the direction of interfering signals at the receiving antenna 3, the signal from the power transformer 4 is transmitted to the receiver 1 mains, phase coupled Nala interference coming from the receiving antenna 13. With the attenuator 10, the switch 8 and the WB 6 is performed compensation phase adjustment signal interference level and phase. The second channel, consisting of block 12, attenuator 11, BB 9, and switch 7, provides for adjustment of the quadrature-compensating signal. 1 il. (L -. 00 ate O5 ISD 4 CO

Description

The invention relates to radio engineering and communications and can be used to transmit information on the territory of manufacturing enterprises.

The aim of the invention is to increase the number of rooms

The drawing shows the structural electrical circuit of a fixed receiving device for an inductive communication system.

The fixed receiving device for the inductive communication system comprises a receiver 1, a loudspeaker 2, a power supply unit 3 comprising a power transformer 4, an adder 5, first and second switches 6 and 7, first and second buffer blocks 8 and 9, first and second attenuators 10 and 11 and. block 12 amplitude-phase correction receiving antenna 13,

A fixed receiving device for an inductive communication system operates as follows

3

The signal from the communication channel is fed to the first input of receiver 1 and, after amplification and the corresponding conversion (detection), is reproduced by loudspeaker 2 installed at the work station of the second subscriber. The required power supply of the electronic circuits of the stationary receiver is provided by unit 3 via the power buses. Work races

of the observed inductive system, a bass receiver, to the first input of the kozi is complicated by the fact that in addition to the useful signal at the terminals of the receiving antenna 13, interfering signals are induced, the main sources of which are wired and cable lines of the power grid of the enterprise. To eliminate undesirable effects of power networks, receiver 1 is supplied with a second input to which a disturbance signal is supplied from the power network, which is out of phase with the disturbance signal at the first input of receiver 1. The compensation signal forming circuits can be connected to the network not directly, but through power transformer - 50 phase correction, second attenuator

Matrix 4 of block 3. This eliminates the need to use a special device for connecting to the power network for a compensating signal generating circuit. A compensation channel can be used to form a signal that compensates for interference from electrostatic pickups (common-mode noise).

not contributing to phase shifts, but changing only the level of interference arriving at its input from the power network. In this case, the first attenuator 10 provides the ability to adjust the level, and the first buffer block 8 with para-phase outputs together with the first switch 6 provides adjustment of the phase of the signal compensating the common-mode interference.

Claims (1)

Therefore, the interference signal from inductive interference is shifted along; phase 90, t, e. is in quadrature with noise at the terminals of the power network, and has a modified spectral composition. The channel for forming the quadrature interference cancellation signal contains a block 12, made in the form of a first order differentiating element. In this case, the second attenuator 1I provides level control, and the second buffer unit 9 with paraphase outputs, together with the second switch 7, provides adjustment of the phase of the signal compensating for quadrature interference. Signals that compensate for the in-phase and quadrature interference through the adder 5 are fed to the second input of the receiver 1, claims A fixed receiving device for an inductive communication system containing a receiving antenna, a receiver output connected to a loudspeaker, and a power supply unit, the primary winding of a power transformer which is connected to a power network, is characterized in that, in order to improve noise immunity, an adder is inserted United First Attenuator and the first buffer block, the paraphase outputs of which through the first switch are connected to the first input of the adder, as well as serially connected amplitude-amplified five and the second buffer block, the paraphase outputs of which are connected via the second switch to the second input of the adder, whose output is connected to the second input of the receiver, while the combined inputs of the first attenuator and the amplitude-phase correction unit are connected to the power transformer of the power supply unit.