RU1774469C - Device with programmable and controllable regulation of transmission factor - Google Patents

Abstract

Usage: radio equipment transmitting and receiving equipment. The inventive device with programmable and controlled adjustment of the transmission coefficient contains a discrete attenuator, a driver of the control signal, an indicator, a pulse generator of the interrogation, including a pulse generator, a counter, a decoder and a delay element, a comparison element. The device monitors the passage of the control signal , which allows you to detect a failure in any element of the control signal generating circuit. 2 ill.

Description

The invention relates to radio engineering and can be used as a reading and software device for controlling power in the paths of radio transmitting and receiving equipment for various purposes in the radio engineering industry and communications, where electrically controlled attenuators are widely used as devices with adjustable transmission coefficient,

In the conventional control circuits, the attenuator input attenuation has not yet been given special significance due to the lack of sufficiently accurate and reliable control circuits for these attenuators.

The development of digital integrated circuitry has allowed the development of high-precision control circuits in this area, which

put forward the urgent need to implement a reference system and control in devices with an adjustable gear ratio.

Known electrically controlled attenuator (see ed. St. isfe 1078506, class N 01 P 1/22), containing a transmission line with pin diodes, a control voltage source, a power source and a control transistor, the collector of which connected to pln diodes, and the base connected to a voltage source, resistive divider, n transistors. In this case, the emitter of the control transistor is connected to the resistive divider and the emitter of the first transistor, which is connected in a circuit to a common collector. The emitters of the remaining p-1 transistors are connected to the corresponding taps of the resistive divider, and

Xi

4 4

B

H

their collectors and bases are connected respectively to the collector and base of the control transistor.

The disadvantage of this device is the lack of scaling of the input attenuation, because the existing discrete control does not determine the absolute values of the transmission coefficient and. furthermore, no individual triggering is indicated. components of the resistive divider, which makes it impossible to evaluate the dynamics of the divider and reduces the accuracy of the control.

A device for changing the scale of the input signal (see ed. St. No. 417862, CL H 01 P 1/22), comprising a voltage divider connected through relay contacts with an amplifier, comparing elements, a reversible counter, through a diode matrix and valves connected to a digital indicator and to the relay windings, an amplitude detector connected between the output of the amplifier and the common input of the comparing elements, the outputs of which are connected to the inputs of addition and subtraction of the reversible counter through additionally entered keys that control the inputs of x connected to outputs of the first and last gates respectively. The disadvantage of this device is the low accuracy of control, because the indicator is connected to the outputs of the valve group, which does not allow monitoring the status of subsequent links of the device, relays and their contacts, resistive divider. As a result, failure of one of them is not detected. In addition, it is impossible to determine the failure of even controlled elements, because indications of the available indicator it is impossible to compare fie with what and to judge the accuracy of work. Based on the available indications, only the dynamics of the device can be judged.

The closest in technical essence and the achieved effect to the proposed invention is a programmable readout step attenuator on p-1-n-diodes (see the journal Telecommunication Technology, series Radio Measuring Equipment, M .: issue 5,1977, pp. 1-19 ; become GB Dzekhtser Design of broadband control devices for microwave power on n-diodes). Said attenuator comprises an N-bit decoder, an M-channel switch, an indication unit, an inverter, a key-setting key unit, a PIN attenuator.

The device operates as follows. The input signal is applied to a semiconductor controlled attenuator, the transmission coefficient of which is determined by the value of the N-bit digital code at the decoder input, which is received from the remote control device. Decoder converts the received code

to the control command of the switch, which from the output of the decoder enters the input of the M-channel switch, where, by the received command, the control voltage of the current-setting keys is generated.

0 The generated voltage using the inverter is consistent with the control levels of the current-setting keys and is input to the block of the indicated keys. In this block, when the signal arrives, the keys are triggered,

5 corresponding to a given attenuation discrete and switching current to a common load (attenuator diodes). The level of attenuation is determined by the magnitude of the current specified by the pick-up key or

0 by a group of keys, and a certain key or group of keys corresponds to a given attenuation. An indication of the operation of a programmable readout attenuator on p-i-n-diodes is provided

5 according to the state of the M-channel switch. The diode group of the PlN attenuator is controlled by its three-bit decoder and current-setting key block.

The disadvantage of this device is

0 that when counting the attenuation introduced by the PIN attenuator into the microwave path, only the command coming from the N-bit decoder is displayed, i.e. driving action. In connection with the aforementioned, any malfunction in the inverter’s operation, no current key blocking of their keys is detected, which reduces the accuracy of the control. A significant disadvantage of the device is the lack of information about the incoming control command,

0 since the indicator captures data on the operation of the decoder and the M-channel switch. The latter reduces the accuracy of the control due to the lack of identification of malfunctions in the operation of the decoder or the M-channel switch5.

The purpose of the invention is to increase the accuracy of control by introducing complete tracking of the performance of the driver.

0 The goal is achieved in that a D device with programmable and controlled adjustment of the transmission coefficient, containing a discrete attenuator, to the control input of which there are 55 keys a driver of the control signal, including a block of current-setting keys, the outputs of which are the output of the driver of the control signal, and each made of current-setting keys

on a transistor with a current-limiting resistor in the collector circuit, and an indicator connected to the driver of the control signal, while the inputs of the driver of the control signal are the code input of the desired transmission coefficient of the device, according to the invention, the driver of the interrogation signals are introduced in the form of series-connected pulse generator, counter and a decoder, the outputs of which are the outputs of the driver of the polling signals, the output of the reset signal of the decoder is connected to the reset input of the counter and a delay element connected between the output of the pulse generator and the V-input of the decoder, and a comparison element, the inputs of which are connected to the code inputs of the required transmission coefficient of the device and the indicator outputs, the inputs of which are connected to the transistor collectors of the current-generating key block of the control signal generator, the indicator is made in inverters, the inputs of which are inputs of the indicator, AND-NOT elements, some of whose inputs are connected to the outputs of the inverters, and others are the control input of the indicator, and consequently connected OR element, the inputs of which are connected to the outputs of the AND-NOT elements, a counter and a memory element, the output of which is the indicator output, and the indicator control inputs are connected to the outputs of the interrogator, the counter reset input and the recording input of the indicator memory element respectively connected to the output of the reset signal and the high-order output of the decoder of the interrogator of the polling signals.

In FIG. 1 shows a structural diagram of the structure; in FIG. 2 is a timing chart of a code comparison process. The device with programmable and controlled regulation of the transmission coefficient contains a discrete attenuator 1, to the control input of which a control signal generator 2 is connected, including a block D of okay keys, the outputs of which are output to the outputs of the driver 2 of the control signal, and the current keys are made on transistors Ti, ., Tm with current-limiting resistors Ri.,. Rm of the collector circuit, indicator 3 connected to the control signal generator 2, the inputs of the driver 2 being the input of the desired code the transmission coefficient of the device, the generator 4 of the polling signals in the form of sequentially connected pulse generator G, counter D 8 and the decoder D 9, the outputs of the bits of which are the outputs of the generator 4 of the polling signals, the output of the MS of the reset signal of the decoder D 9 is connected to the exit of the counter reset D 8 and a delay element D 10, connected between the output of the pulse generator G and the V-input of the decoder D 9, and a comparison element 5, the outputs of which are connected to the code inputs of the required transmission coefficient of the device and the output of indicator 3, input of which are connected to the collectors of transistors TI ... TR of block D of the current-generating keys of driver 2 of the control signal, indicator 3 is made about B1; de inverters 15 D3.1 ... D3.m, the inputs of which are inputs of indicator 3, elements And -NOT D4.1 ... D4.rn, some of whose inputs are connected to the outputs of the inverters D3.1 ... D3.m, and others are the control input 0 of indicator 3 and series-connected elements OR D5, the ports of which are connected to the outputs of the AND-NOT elements D4.1 ... D4, m, the Ob counter of the memory element D 7, the output of which is the output 5 of indicator 3, and the control the inputs of indicator 3 are connected to the outputs of driver 4, the reset input of counter D 6 and the recording input of element D 7 of the memory of indicator 3 are connected respectively to the output 0 MS of the reset signal and the output Ms of the high order of the decoder D 9 of generator 4 of the polling signals.

The device operates as follows. In the initial state, an adjustable 5 radio signal is supplied to the input of the discrete attenuator 1. The transmission coefficient of which is determined by the value of the N-bit digital code at the input of the decoder D 1 of block A of driver 2 of the control 0 signal, which comes from the remote control device. The logical command from the output of the decoder D 1 is fed to the input of the M-channel switch of the block B of the driver 2 of the control 5 signal. The M-channel switch is intended for converting the logical command of the decoder D 1 to the command for controlling the current switches of the block D of the driver 2 of the control signal. The indicated 0 command allows turning on the current keys corresponding to the output number of the decoder D1 and turning off the keys working before. In a particular device, the decoder D 1 contains a chip 133IDZ with inverted outputs, and therefore the M-channel switch in block B, built on AND-NOT elements of the 133LAZ series, interprets the logic zero from the output of the decoder D 1 as a logical command to inclusion of appropriate current-setting

keys. Since there is only one logical output of the decoder D 1 for each code combination, and for setting the required control current to the discrete attenuator 1 in a particular device, a different number of parallel keys is required, the command from the decoder D 1 is branched into several exact keys with using the M-channel switch and inverters of block C of the driver 2 of the control signal. These commands are input to the block D of transistor current-setting keys. In the collectors of the transistors Ti ... Tm of the current-carrying keys, there are resistances Ri ... Rm, which determine the current through the public key.

In a specific example of the device, the attenuator was assembled on six p-l-n-diodes connected in parallel with the carrier frequency path. Under the action of the current set by the current-setting keys of the D block, p-I-n-diodes begin to bypass the carrier frequency path, introducing a certain attenuation into it, characterized by the number of discrete samples of the attenuation of the radio signal. When tuning, the collector resistances Ri ... Rm of the current-setting keys of the block D are selected so that the inclusion of certain keys under the action of the code command corresponds to a certain current simultaneously through all p-1-p-diodes of the attenuator, which as a result introduces a corresponding attenuation into the path . . All six stages of pin diodes included in the path represent the total load in the emitters of the current-sensing keys, since the state of the transistors Ti ... Tm of the current-sensing keys in the collector is monitored using the inverters D3.1, .. D3.m of indicator 3, from the outputs of the latter at the first inputs of the two-input logic elements I / 1-HE D4.1 ... D4.m, signals appear corresponding to the changed state of the transistors Ti ... Tm of the current-setting keys.

For example, the transition of transistors Ti, .. Tm to the open state at full saturation corresponds to a logic zero at the input of inverters D3.1 ... D3.m (on the collector of an open transistor, the voltage is close to zero when the transistor is turned on according to the common emitter circuit ), and the first inputs of the elements D4.1 ... D4, m from the inverters D3.1 ... D3.m receive logical units. In order to indicate and control the entered attenuation, it is required to determine the number of current-sensing keys switched on. The interrogation of the state of the keys is performed using the interrogator 4 of the interrogation signals. Shaper 4 is a pulse distributor designed for sequential transmission of pulses from a clock generator

(GTI) G by means of a counter D 8 to one of the M outputs of the decoder D 9 depending on the sequence number of the sequence pulses. From the outputs of the decoder D 9, interrogation pulses are fed to the control 0 inputs of indicator 3, which are formed by the second inputs of the elements D4 / 1.,. D4.m. Although the decoder D 9 is a static element, gating pulses from the delay element D 0 arriving at its V input

5 make it possible to generate a polling signal in the form of a pulse.

By pulse interrogation signals from the output of the combining element D 5, the inputs of which are signals in the form of pulses

0 come from the elements D4.1, .. D4.m the burst of pulses goes to the counter D 6. The number of pulses in the burst is equal to the number of open lead-in transistors Ti ... Tm. The specified number in the form of a code from the counter output

5 D 6 enters the memory element D 7, where it is recorded by the interrogation pulse Ms. The outputs of the memory element D 7 are used for direct digital indication and are simultaneously connected to the second inputs of the kodoo comparison element 5, at the first inputs of which the control external device holds a given command to weaken at least until the Ready signal is received. This signal indicates the correspondence of the fulfilled command given at the input of the device. According to the interrogation pulse Ms, the counters D 6, D 8 are reset to zero, since the control result is already stored in the memory element D 7. Then, the polling cycle is repeated, but the memory element D 7 stores the information obtained in the previous cycle until the end of the subsequent polling cycle. No signal, Ready indicates an input mismatch

5 information and functional state of the attenuator. As a result, a failure is automatically detected. By checking the input command and comparing it with the indicator readings, you can also establish a failure circuit. AT

In a specific example of the device, the inclusion of each key that was assigned corresponds to an attenuation of 1 dB. In this regard, the counter D 6 forms at the outputs a numerical code corresponding to the value of the entered

5 attenuation with 1 dB sampling,

In FIG. Figure 2 shows the timing diagrams of the process of comparing codes (given and interrogated) for the case of a three-bit parallel binary code corresponding to the number two. On the specified command

two current-sensing switches are turned on for transistors Ti and T 2 (Fig. 1). The first clock pulse of the polling cycle controls the transition to the open state of transistor Ti, and the second transistor Jz. Provided that both transistors are in full saturation mode, two pulses following each other appear at the output of element D 5, arriving at the counting input of counter D 6. Since the command to turn on two keys was received at the input of the device, the uptime of the device at the output of the counter D 6 at the end of the polling cycle, a code of two appears, and the specified code is written to memory D 7. Since the input control command is held at the first input of the comparison element 5, and the second code appears at the second input of the polling cycle from the output of memory D 7, a Ready signal is generated at its output, informing the external control device about the execution of a given command. For different numerical codes at the inputs of the comparison element 5, there is no Ready signal. This means that at the end of the polling cycle, the external control device does not receive confirmation of the execution of the given command, and as a result the next command does not arrive, and the system is informed of the failure. The use of the invention makes it possible to synchronize the receipt of control commands with the process of their execution, which eliminates, for example, overshoot in automatic control systems, and automatically detects a failure in any executive link up to the elements of the control object. The principles embodied in the described device can be used with other types of attenuators or methods for controlling them.

For example, in attenuators with discrete resistances, the switching of the latter takes place using relays. By monitoring the status of the relay contacts and comparing the result with the control command, it is also possible to synchronize the execution of commands and detect a failure at any link of the device. Or another example, In the p-i-n-diode attenuator, attenuation is introduced by the current switch corresponding to this command, the rest are turned off. Then it is not the number of keys included that is counted as in the invention, but the key sequence number. In this case, the counter counts the pulses of the interrogator of the polling signal, and

an impulse resulting from the detection of an open transistor key stops the operation of the counter. As a result, the sequence number recorded in the counter indicates the entered attenuation.

Claims (1)

SUMMARY OF THE INVENTION A device with programmable and controlled adjustment of the transmission coefficient, comprising a discrete attenuator, to the control input of which a driver of a control signal is connected, including a block of current-generating keys, the outputs of which are the output of the driver of the control signal, and each of the current-generating keys is made on a transistor with a current-limiting resistor in the collector circuit, and an indicator connected to the driver of the control signal, while the inputs of the driver of the controller the signal is the input of the code of the required transmission coefficient of the device, characterized in that, in order to increase the accuracy of the control, the polling signal generator is configured in the form of series-connected pulse generator, counter and decoder, the bit outputs of which are the outputs of the signal generator interrogation, and the output of the decoder reset signal is connected to the counter reset input, and the delay element connected between the output of the pulse generator and the decoder V-input, and the CPA element the indicator, the inputs of which are connected to the inputs of the code of the required coefficient of the device and the outputs of the indicator, the inputs of which are connected to the collectors of transistors of the block of current-setting keys of the driver of the control signal, the indicator is made in the form of inverters, the inputs of which are inputs of the indicator, NAND elements, some of which are connected to the inverter outputs, and the others are the control input of the indicator, and the OR element connected in series, the inputs of which are connected to the outputs of the NAND elements, the counter and the memory element and whose output is the output of the indicator, wherein the indicator control inputs connected to the output of the interrogation signals, the reset input of the counter and the recording element memory input indicator are respectively connected to the output of the reset signal and the output of MSB decoder shaper interrogation signals. The code ejRpat jt & ff (J8 t GotoVnsst Fugue. 4 FIG. g