SU1378041A1 - Device for contactless switching of radio receiver bands - Google Patents

Abstract

This invention relates to analog signal switching technology. The contactless switching device of the frequency ranges of the radio receiver contains n analog switches on transistors 12, 13 of different conductivity types, resistors 1, 2, p LED indicators, 8 frequency ranges, varicaps 9, n ballast resistors 19, 2p of capacitors 20, buses 21 and 22 local oscillators and radio frequency amplifiers, respectively, p-1 of buttons 6 of quasi-sensor range switch, p-1 limiting resistors 7. The device is simple in design and has reduced power consumption, 1 slug. i (L

Description

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The invention relates to the field of analog signal switching and can be used in radio and measuring receivers, generators and amplifiers of sound and radio frequencies.

The aim of the invention is to simplify and reduce power consumption.

The drawing shows a circuit diagram of the proposed device.

The device contains 1, 2 resistors. The priority switching circuit of the first frequency range on the capacitor 3 and the ballast resistor 4, the isolating capacitors 5 are connected in series with the buttons 6 of the quasi-touch switch ranges and the limiting resistors 7, n LED indicators frequency ranges — LEDs 8, two varicaps 9 for each of the frequency ranges controlled by voltage filters; settings on capacitors 10 and resistors 11; n analog switches are carried out on transistors 12 and 13 of different types spines, two resonant LC circuits for each frequency range with coupling elements 14 for an RF amplifier, resonant chains 15, 16, coupling elements 17 for the local oscillator, connected in series by windings 18

feedback of the local oscillator, p ballast resistors 19 and decoupling capacitors 20, and buses 21 and 22 of the local oscillator and radio frequency amplifier.

Due to the direct current connections, the resistors 19 and the LEDs 8 of the transistors 12 and 13 combine them into trigger cells in pairs, and through the common for all RF amplifier keys, the resistor 2 and all the keys of the local oscillators, the resistor 1 of the cell are combined into a multi-phase trigger of the control unit. The capacitors 5, 20 block the trigger connection elements for the frequencies of the alternating current signals by passing 1x transistors of the included trigger cell to the buses 22 and 21. Resistors 1, 2 also play the role of load resistances in each switching channel and ensure the installation of the included transistors in linear mode

LEDs 8, except for the indication of the included multi-phase trig cell

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Hera, provide stabilization of the mode of operation of transistors 12 and 3 when the supply voltage changes.

All simultaneously tunable resonant circuits 15, 16 are connected to the bases of transistors 12 and 13 through coupling elements 14 and 17. The heterodyne feedback windings 18 for all ranges are connected in series so as to provide the necessary phase balance depending on the heterodyne transistor. Resistors 7 - current limiters through the LEDs 8 when the buttons 6 are closed.

When the supply voltage is applied, all capacitors connected (including through resistors) to the power bus are charged. At the same time, the largest charge current flows through the priority switching circuit due to the fact that the capacitance of the capacitor 3 is chosen to be of considerable size. For the same reason, the charge current in this circuit is much longer. The voltage drop across the resistor 19 briefly opens the transistor 12. The collector current of this transistor, flowing through the LED 8, creates a voltage drop from 1.5 to 2.2 V on it, depending on the type of LED used. This voltage opens up the transistor 13 and thereby creates its collector current, which flows through the resistor 19 and keeps the transistor 12 in the open state despite the stopped or stopped charging current of the priority connection circuit. The collector currents of transistors 12 and 13 V, static mode, are determined by the voltage drop across the LED, which plays the role of a Zener diode in the base circuit of transistor 13, a resistor 1 in the emitter circuit and a resistor 19 in the collector circuit of transistor 13, from which the voltage is removed to the base transistor 12, the current of the emitter (collector) of which is set by resistor 2. All these elements in all cells must be the same. (+ 5-10%). By the voltage drop across the resistors 1 and 2, the transistors of the malleable cells turn out to close and

When any button 6 is pressed, except for the cell already turned on, the LED 8 (for example, the second cell) that was previously turned off is energized through the starting resistor 7,

which, due to the selected resistor value 7, which provides more current through the LED during start-up than in the static mode of operation, becomes briefly more than on the LED of the first (on) cell. As a result, the voltage at the base, and hence the emitter of the transistor 13 of the second cell, becomes greater than the corresponding voltages at the transistor 13 of the first cell, and the first cell is turned off. After releasing the button 6, the voltage on the LED 8 of the second cell is reduced to values 1 consumed by the mode (collector current) of the transistor 12 of the second cell, and it is set to static mode. Similarly, if you briefly press any button 6 that is not working at the moment of the cell, it is turned on in the static mode.

The term “phase trigger” corresponds to operation in a dynamic mode, when the voltage in a clock with the clock frequency appears on each of the outputs, taking each of the states of the switching device as one of the phases of its state.

The operating system circuit (feedback) must be connected to the corresponding output of the radio circuit of the receiver, and on the reverse side (past the last cell) it must be connected to the power source. With a larger number of cells, the circuit is turned on after the new last cell. In the transistor version, the collector of the transistor-heterodyne is connected to the OG circuit, and the base circuits of the transistors of the heterodyne and amplifier-radio frequencies, respectively, are connected to the buses 21 and 22.

Claims (1)

Thus, the proposed device is simple and economical in energy consumption, since the same transistors are used both in the control device and in the actuator, and the LEDs - indicators of the switched on cell are included in the power supply circuit of one of the transistors and do not consume additional energy. . Invention Formula Contactless switching device of radio frequency bands five 0 five ka, containing n analog switches, each of which is made on a transistor of the first conductivity type, the emitter of the first of which is connected via the first resistor to a common power supply bus, n analog switches, each of which is made on the transistor of the second conductivity type, the emitter of the first of which is connected with the first output of the second resistor, two resonant LC-circuits controlled by varicaps for each of the frequency ranges, n LED indicators of the frequency ranges and the main button of the quasi-sensor lane a range switch, the first output through a limiting resistor connected to a common power supply bus, a priority switching circuit of the first range, 2p of decoupling capacitors, n ballast resistors and heterodyne and radio frequency amplifier, is, in order to simplify and reduce power consumption power, introduced n-additional buttons quasi-sensor switch ranges with n-1 limiting resistors, with the emitters of the transistors of the third type of conductivity connected to the amplifier bus radio frequencies, emitters of transistors of the second type of conductivity - to the local oscillator bus, the base of each of the transistors of the first conductivity type is connected to the collector of the transistor of the second type of conductivity of the same type of frequency through a ballast resistor shunted by a blocking capacitor is connected to the common power supply bus, each additional button of the quasi-touch switch of ranges is the first pin of the es corresponding limiting resistor connected to the common bus of the power supply, a second terminal of each button is connected to the collector of a corresponding transistor of the first conductivity type, obradnoy communication winding loops ge- terodana all bands are connected in series, and the second terminal of the second resistor connected to the source bus pit Ani 0 five 0 0 five