SU1070708A1 - Multi-frequency signal receiving device - Google Patents

Abstract

A device for receiving multi-frequency signals, a clock generator and an amplitude detector, characterized in that, in order to increase the number of received signals, a band-pass filter with switched capacitors and a serially connected state counter, a variable division factor block, a divider with a variable division factor, are introduced into it and a switching signal generator, the output of which is connected to a controllable input of a band-pass filter with switched capacitors, the output of which is connected With an inLormation input of an amplitude detector, the output of which is connected to the input of a state counter, the information input of which is connected to the second output of a divider with a primary division factor, the information input of which is connected to the output of a clock generator. kn

Description

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The invention relates to radio engineering and communication and can be used in control equipment of electronic and quay electronic telephone exchanges.

A known device for receiving multi-frequency signals comprising band-pass filters / resonant circuits, limit amplifiers, detectors, logic blocks, and a driver 1.

The disadvantage of this device is the limited number of received signals, determined by the number of bandpass filters, resonant circuits, limiter amplifiers and detectors.

The closest technical solution to the invention. a device for receiving multi-frequency signals, comprising a clock generator and an amplitude detector 12.

A disadvantage of the known device is the small number of received signals.

The purpose of the invention is to increase the number of received signals.

The goal is achieved by introducing a band-pass filter with switched capacitors and a serially connected state counter, a block for changing the division factor, a divider with a variable division factor, and a switch shaper, the output of which is a device for receiving multi-frequency signals containing a clock generator and amplitude detector connected to a controllable input of a band-pass filter with switched capacitors, the output of which is connected to the information input of an amplitude detector and whose output is coupled to audio vhdom counter state, an information input coupled to a second output of the divider with a variable division ratio, an information input coupled to an output of the clock generator.

The drawing shows the structural electrical circuit of the device for. receiving multi-frequency signals.

The device contains a clock generator 1, a band-pass filter 2 with switched capacitors, a driver of 3 switching signals, a divider 4 with a variable division factor, an amplitude detector

a division change factor unit 6 and a state counter 7.

The device works as follows.

. When a multi-frequency signal arrives, the band-pass filter 2 analyzes the presence of all the expected frequencies in. input signal by switching capacitors and thereby changing the center frequency

0 filter pass. When the input and switching frequencies coincide, the output of the bandpass filter 2 causes a signal arriving at the amplitude detector 5. When the signal at the input of the amplitude detector 5 of the predetermined threshold is exceeded, the signal from the output of the amplitude detector 5 blocks the operation of counter 7. Counter 7 displays the input

0 signal. In binary form. The selection time is set by divider 4 and depends on the number of analyzed frequencies of the input signals and their division. Counter 7 sets the division ratio

5 through block 6 of divider 4, which operates at a frequency corresponding to. sight of a multi-frequency signal. The imaging unit 3 switches the capacitors of the bandpass filter 2 at a frequency that is a multiple of the first expected signal. If band-pass filter is not 2. skips the input frequency, the prohibition signal from the amplitude detector 5 is not received at the input of counter 7. Divider 4 translates

5, the state counter 7 to the second position (corresponding to the code of the second frequency); in this case, the division ratio of the divider 4 through block 6 changes;

0 shaper 3 will, frequency, edge on the second estimated signal. If these frequencies do not match, counter 7 is transferred to the third position. Thus, all expected frequencies will be rebased to match. When the frequencies coincide with the output of counter 7, the signal corresponding to the code of the received multi-frequency signal is taken.

0 The state counter 7 has a number of states equal to the number of received multi-frequency signals. The use of the invention allows to increase the number of received multi-frequency signals without

increase the number of bandpass filters while maintaining high precision signal selection.

Claims (1)

DEVICE FOR RECEIVING MULTI-FREQUENCY SIGNALS, containing a clock generator and an amplitude detector, 'characterized in that, in order to increase the number of received signals, a band-pass filter with switched capacitors and series-connected state counter, a division coefficient change unit, a divider with a variable are introduced into it dividing factor and switching signal generator, the output of which is connected to the controlled input of a bandpass filter with switched capacitors, the output of which is connected to ormatsionnym input of amplitude detector, whose output is connected to the input state of the counter, an information input coupled to a second output of the divider with a variable division ratio, an information input coupled to an output of the clock generator with the torus. ® ω