CS260368B1 - Connection for electric signal's galvanic separation - Google Patents

Description

The invention provides a circuit for the galvanically isolated transmission of an unidirectional as well as an alternating electrical signal with or without a unidirectional component using Schottky mixer diodes integrated on a single chip.

To date, known wiring uses transistors in the transistor's current in galvanic isolators bring about an error that is increased by the imbalance of these switching elements. It is known to use MOS-FET transistors as switching elements of modulators, the disadvantage of which is lower transmission efficiency, complex circuit realization and the risk of damage to the switching elements in case of accidentally exceeding the allowed input levels. Also known is a wiring with a V-MOS transistor as a switch, which reduces the risk of destruction of the switching element, but is characterized by a considerable, complex circuit realization. A common disadvantage of these circuits is the necessity of galvanic isolation of the modulator power supply.

These drawbacks are overcome by the circuitry of the present invention, which is based on the output of a carrier frequency generator producing auxiliary periodic alternating voltage. is coupled to the inputs of the first and second decoupling broadband transformers. The output of the first isolation broadband transformer is coupled to the second input of the first creation of Schottky diode mixers. The output of the second isolation broadband transformer is coupled to the second input of the second generating Schottky diode. The output of the protective circuit is coupled to the first input of the first generating Schottky diode, whose output is coupled to the input of the third decoupling broadband transformer. Its output is connected to the first input of the second generating Schottky diode whose output is connected to the filter input. At its output, the signal is proportional to the signal applied to the input of the protective circuit, with all signals involved in the transmission being galvanically isolated from each other.

The connection for the galvanically isolated transmission of the electrical signal according to the invention makes it possible to excite the mixers at a high frequency which can reach hundreds of MHz. The high excitation frequency enables the technical realization of the coupling transformers they provide! also galvanic separation of input and output. The location of the mixing diodes in one housing minimizes the effect of thermal changes on the mixer distribution, reducing drifting into the output signal. The advantage of the connection according to the invention is also substantially simpler circuit realization compared to the known solutions, which creates conditions for low cost. The entire wiring does not require adjusting elements, which increases reliability.

The attached figure is a block diagram for the galvanic separation of an electrical signal with an optional unidirectional component according to the invention.

The circuit according to the invention consists of a protective circuit 7, the output of which is connected to the first input of the first generating Schottky diode 3, the output of which is connected to the input of the third decoupling broadband transformer 4, and whose second input is connected to the output of the first decoupling broadband transformer 2. The output of the third decoupling broadband transformer 4 is connected to the first input of the second quadruple Schottky diode 5, the output of which is connected to the filter input

8. The second input of the second four mixing Schottky diodes 5 is connected to the output of the second decoupling broadband transformer 6, the input of which is connected to the input of the first decoupling broadband transformer 2 and the output of the carrier frequency generator 1.

The function of the device according to the invention is as follows: The input electrical signal passing through the protective circuit 7 in the first four mixing Schottky diodes 3 is mixed with the carrier frequency signal coming from the carrier frequency generator 1 through the first decoupling broadband transformer 2. The mixed signal passes through the third decoupling broadband. transformer 4 into a second quadruple of Schottky diodes 5 in which the carrier frequency is suppressed. The transmitted signal is filtered in the filter 8, leaving a signal proportional to the signal at the output of the protective circuit 7, which serves to protect the mixing diodes from being awakened by the input signal.

The wiring according to the invention can be used in all electrical devices where transmission of a voltage level signal of the order of hundreds of mV with galvanic separation of input and output is required.

Claims (1)

Zopojonie pre-galvanic separation of electrical signal using auxiliary periodic alternating voltage from the carrier frequency generator, characterized in that the output of the carrier frequency generator (1) is connected to the input of the first decoupling broadband transformer (2) and the input of the second decoupling broadband transformer (6). the output is coupled to a second input of a second generating Schottky diode (5), wherein the output of the first decoupling broadband transformer (2) is coupled to a second input of a first quadruple of the mixing Schottky diodes (3j) whose first input is coupled to the output of the protective circuit (7) wherein the output of the first four Schottky diodes (3) is coupled to the input of a third decoupling broadband transformer (4), the output of which is coupled to the first input of the second Schottky diodes (5j), the output of which is coupled to the a filter stage (8) at the output of which a galvanically isolated electrical signal is proportional to the input signal applied to the input of the protective circuit (7).