RU2196383C1 - Functional angle-code-to-sine-cosine-voltage converter - Google Patents

Abstract

FIELD: computer engineering; automatic control and data measuring technique. SUBSTANCE: device has two digital-to- analog converters, reference-voltage source, four storage components built around capacitors, pulse generator, counter, NOT gate, two registers, functional angle-code-to-sine-and-cosine code converter unit, four switches, two subtracting amplifiers, two modulators, and threshold unit. EFFECT: enhanced precision of conversion, enlarged functional capabilities. 2 dwg

Description

 The invention relates to the field of computer technology, in particular to code to voltage converters, and can be used in data processing systems.

 A known code-voltage converter containing a reference voltage source, a resistive divider R-2R, transistor switches and a summing amplifier (see AS USSR, 324704, class N 03 K 13/03, 1970).

 The disadvantage of the converter is its low accuracy characteristics and high hardware costs.

 The closest to the invention in technical essence and the achieved result is a code-voltage converter containing (see patent 1826837, class N 03 M 1/66, 1991) a digital-to-analog converter, the input of which is connected to the output of the reference voltage source, digital inputs connected to the output of random access memory, and the output is connected to the information input of the N-channel switch with a decoder, the outputs of which are connected from the first to the nth with the corresponding inputs of the buffer repeaters and the first plates of capacitors, the second circuits of which are combined and connected to the zero potential bus, the outputs of the buffer repeaters are the output bus of the converter, the information input of random access memory is the first input bus of the converter, and the address input is combined with the first control input of the N-channel switch with the decoder and connected to the output of the counter, the information input of which is the second input bus of the converter, and the input "installation permission" is combined with the input of the element It is NOT the third input bus of the converter, the output of the element is NOT connected to the counter resolution input, the RAM input and the second control input of the N-channel switch with the decoder, the pulse generator output is connected to the counter input and the read input of the random access memory .

 The disadvantage of the converter is the low accuracy due to the offset and drift of zero in the path of digital-to-analog conversion, as well as its limited functionality.

 The purpose of the invention is to increase the accuracy characteristics of the Converter and the expansion of its functionality.

 This goal is achieved by the fact that the code-voltage converter contains the first digital-to-analog converter, the analog input of which is connected to the output of the reference voltage source, four storage elements made on capacitors, one of the plates of which are combined and connected to the zero potential bus, a pulse generator, the output of which is connected to the counter input of the counter, the input of "resolution of the account" of which is connected to the output of the element NOT, the input of which is connected to the sync input of the converter, the second digital-to-analog converter, the functional converter block of the angle code into the sine and cosine code, the first, second, third and fourth keys, the first and second subtracting amplifiers, the first and second modulators, the threshold block, the first and second registers, the information inputs of the first of which are the job input converter angle code, the information inputs of the second are connected to the zero potential bus, the recording inputs are combined and connected to the disconnect input of the output of the first register and the input of the element NOT, and the outputs are combined s and connected to the input of the functional conversion unit of the angle code into the sine and cosine code, the first and second outputs of which are connected respectively to the digital inputs of the first and second digital-to-analog converters, the analog input of the second of which is connected to the analog input of the first digital-to-analog converter, the first output of the counter is connected to the control input of the first key, and the second output with the control input of the second key and with the input "direct / inverse" of the second register, the output disable input of which is connected to control inputs of the third and fourth keys and is connected to the output of the element NOT, the inputs of the first and third keys are combined and connected to the output of the first digital-to-analog converter, and the outputs are connected respectively to the first input of the first subtracting amplifier and another lining of the first capacitor and the second input of the first subtracting amplifier and another the lining of the third capacitor, the inputs of the second and fourth keys are combined and connected to the output of the second digital-to-analog converter, and the outputs are connected respectively So, with the first input of the second subtracting amplifier and another lining of the second capacitor and the second input of the second subtracting amplifier and another lining of the fourth capacitor, the outputs of the first and second subtracting amplifiers are connected respectively to the information inputs of the first and second modulators, the outputs of which are respectively the sine and cosine voltages of the converter , and the control inputs are combined and connected to the output of the threshold block, the input of which is the input of the variable converter voltage.

 The structural diagram of the functional converter of the angle code into sine-cosine voltages is presented in Fig. 1, timing diagrams of its operation - in Fig. 2.

 The functional converter of the angle code into sine-cosine voltages contains the first 1 and second 2 registers, element NOT 3, block 4 of the functional conversion of the angle code into sine and cosine code, the first 5 and second 6 digital-to-analog converters, the voltage reference source 7, an 8-pulse generator, counter 9, first 10, second 11, third 12 and fourth 13 keys, first 14, second 15, third 16 and fourth 17 capacitors, first 18 and second 19 subtracting amplifiers, first 20 and second 21 modulators, threshold block 22.

 The information inputs of the first 1 register are the input of the angle code of the converter, the information inputs of the second 2 registers are connected to the zero potential bus, the recording inputs of the first 1 and second 2 registers are combined, connected to the disconnect input of the output of the first 1 register, the input of the element is NOT 3 and are the converter clock , the output of the element NOT 3 is connected to the disable input of the output of the second 2 registers, the control inputs of the third 12 and fourth 13 keys and the input "resolution of the account" of the counter 9, the output of the pulse generator 8 connected to the counter input of counter 9, the first output of counter 9 is connected to the control input of the first 10 key, the second output of counter 9 is connected to the control input of the second 11 key and the direct / inverse input of the second 2 registers, the outputs of the first 1 and second 2 registers are combined and connected to the input of block 4 of the functional conversion of the angle code into the sine and cosine code, the output of the reference voltage source 7 is connected to the analog inputs of the first 5 and second 6 digital-to-analog converters, digital inputs of the first 5 and second 6 digital-to-analog the converters are connected respectively to the first and second outputs of the block 4 for functional conversion of the angle code into the sine and cosine codes, the output of the first 5 digital-to-analog converter is connected to the inputs of the first 10 and third 12 keys, the output of the second 6 digital-to-analog converter is connected to the inputs of the second 11 and fourth 13 keys, the output of the first 10 key is connected to the first input of the first 18 subtracting amplifier and one of the holders of the first 14 capacitor, the output of the third 12 key is connected to the second input of the first 18 subtracting amplifier one of the plates of the third 16 capacitor, the output of the second 11 key is connected to the first input of the second 19 subtracting amplifier and one of the plates of the second 15 capacitor, the output of the fourth 13 key is connected to the second input of the second 19 drinking amplifier and one of the plates of the fourth 17 capacitor, others the plates of the first 14, second 15, third 16 and fourth 17 capacitors are combined and connected to the bus of zero potential, the outputs of the first 18 and second 19 subtracting amplifiers are connected respectively to the information inputs of the first 20 and second 21 modulators, the outputs of the first 20 and second 21 modulators are respectively the outputs of the sine and cosine voltages of the converter, the input of the threshold block 22 is the input of the variable reference voltage of the converter, the output of the threshold block 22 is connected to the control inputs of the first 20 and second 21 modulators.

 Functional Converter code angle to sine-cosine voltage works as follows.

The input code of the angle N _Vxi , coming from an external device, is written to the first 1 register along the leading edge of the corresponding recording signal C _i , by which the code zero value is also written to the second 2 register, since its information inputs are connected to the zero potential bus.

), подключаются ко входу блока 4 функционального преобразования кода угла в код синуса и косинуса. По тому же сигналу с выхода элемента НЕ 3 (

) включается режим пересчета счетчика 9, на счетный вход которого поступает тактовая частота с выхода генератора 8 импульсов. В первый момент времени по сигналу с первого выхода счетчика 9 (см. Фиг. 2), соответствующего уровню "ЛОГ.1", замыкается первый 10 ключ, в то время как по сигналу со второго выхода счетчика 9, соответствующего уровню "ЛОГ.0" и поступающего на вход "прямой/инверсный" второго 2 регистра и управляющий вход второго 11 ключа, второй 2 регистр включен в режиме прямой выдачи информации и его выходы находятся соответственно в нулевом состоянии, что соответствует углу α_i = 0^°, а второй 11 ключ находится в разомкнутом состоянии. Блок 4 функционального преобразования кода угла в код синуса и косинуса формирует на своих первом и втором выходах коды N_sinα_i = 0^° и N_cosα_i = 0^° соответственно, которые поступают на цифровые входы первого 5 и второго 6 цифроаналоговых преобразователей соответственно, на аналоговые входы которых поступает опорное напряжение от источника 7. Первый 5 и второй 6 цифроаналоговые преобразователи осуществляют операцию умножения опорного напряжения, приложенного к их аналоговым входам на соответствующие коды, преложенные к их цифровым входам. В результате на выходе первого 5 и второго 6 цифроаналоговых преобразователей получаем напряжения, пропорциональные синусу и косинусу угла α_i = 0^°, а именно:

где U_оп - опорное напряжение источника 7;
n - количество разрядов цифроаналоговых преобразователей 5 и 6;
ΔU₁, ΔU₂ - напряжения смещения и дрейфа нулевого потенциала в трактах первого 5 и второго 6 цифроаналоговых преобразователей соответственно.At the same time, according to the recording signal C _i , which also arrives at the input for switching off the output of the first 1 register, its outputs are set to the third (high impedance) state, and the outputs of the second 2 registers according to the recording signal C _i passed through the HE 3 element (

), are connected to the input of block 4 of the functional transformation of the angle code into the sine and cosine codes. By the same signal from the output of the element NOT 3 (

) the counter 9 counting mode is activated, the counting input of which receives the clock frequency from the output of the 8 pulse generator. At the first moment of time, the signal from the first output of counter 9 (see Fig. 2) corresponding to the LOG.1 level closes the first 10 key, while the signal from the second output of counter 9 corresponds to the LOG.0 level "and incoming to the input" direct / inverse "of the second 2 registers and the control input of the second 11 keys, the second 2 register is turned on in the direct output mode and its outputs are respectively in the zero state, which corresponds to the angle α _i = 0 ^° , and the second 11 the key is in the open state. Block 4 of the functional conversion of the angle code into the sine and cosine code generates at its first and second outputs codes N _sin α _i = 0 ^° and N _cos α _i = 0 ^°, respectively, which are received at the digital inputs of the first 5 and second 6 digital-to-analog converters, respectively, the analog inputs of which receive the reference voltage from source 7. The first 5 and second 6 digital-to-analog converters perform the operation of multiplying the reference voltage applied to their analog inputs by the corresponding codes encoded to their digital inputs. As a result, at the output of the first 5 and second 6 digital-to-analog converters, we obtain voltages proportional to the sine and cosine of the angle α _i = 0 ^° , namely:

where U _op - the reference voltage of the source 7;
n is the number of bits of digital-to-analog converters 5 and 6;
ΔU ₁ , ΔU ₂ - bias voltage and drift of zero potential in the paths of the first 5 and second 6 digital-to-analog converters, respectively.

The voltage ΔU ₁ from the output of the first 5 digital-to-analog converter through a closed first 10 key is stored on the first 14 capacitor, and the voltage (U _op + ΔU ₂ ) from the output of the second 6 digital-to-analog converter is disabled, because second 11 key is open.

At the next moment of time, when a signal corresponding to the “LOG.1” level appears at the second output of counter 9, the second 11 key closes, the second 2 register switches to the inverse mode of information output and its outputs are in a single state, which corresponds to the angle α _i = 90 ^° , and the first 10 key opens, because the signal corresponding to the “LOG.0” level is present at the first output of counter 9 at this point in time.

Напряжение ΔU₂ с выхода второго 6 цифроаналогового преобразователя через замкнутый второй 11 ключ запоминается на втором конденсаторе 15, а напряжение (U_оп+ΔU₁) с выхода первого 5 цифроаналогового преобразователя отключено, т.к. первый 10 ключ разомкнут.Block 4 of the functional conversion of the angle code into the sine and cosine codes generates at its outputs codes N _sin α _i = 90 ^° and N _cos α _i = 90 ^°, respectively, which, as in the first case, are fed to the digital inputs of the first 5 and second 6 digital to analog converters. As a result of multiplying the reference voltage from source 7, applied to the analog inputs of the first 5 and second 6 digital-to-analog converters by the corresponding codes applied to their digital inputs, at the outputs of the latter we obtain voltages proportional to the sine and cosine of the angle α _i = 90 ^° , namely:

The voltage ΔU ₂ from the output of the second 6 digital-to-analog converter through a closed second 11 key is stored on the second capacitor 15, and the voltage (U _op + ΔU ₁ ) is turned off from the output of the first 5 digital-to-analog converter, because the first 10 key is open.

Thus, during the recording pulse C _i at the first 14 and second 15 capacitors, the voltages ΔU ₁ and ΔU ₂ associated with the offset and drift in the paths of the first 5 and second 6 digital-to-analog converters are stored, respectively.

) выходы второго 2 регистра устанавливаются в третье (высокоимпедансное) состояние, а выходы первого 1 регистра подключаются ко входу блока 4 функционального преобразования кода угла в код синуса и косинуса. По тому же сигналу с выхода элемента НЕ 3 (

) замыкаются третий 12 и четвертый 13 ключи, а первый 10 и второй 11 ключи разомкнуты по сигналам управления с первого и второго выходов счетчика 9. Блок 4 функционального преобразования кода угла в код синуса и косинуса преобразует входной код, записанный от внешнего устройства в первый 1 регистр, в код синуса и косинуса, а первый 5 и второй 6 цифроаналоговые преобразователи осуществляют операцию умножения опорного напряжения от источника 7, приложенного к их аналоговым входам, на цифровые коды, приложенные к их цифровым входам с выхода блока 4 функционального преобразования кода угла в код синуса и косинуса соответственно, в результате чего получаем:

Напряжения с выходов первого 5 и второго 6 цифроаналоговых преобразователей через замкнутые третий 12 и четвертый 13 ключи соответственно поступают на один из входов первого 18 и второго 19 суммирующих усилителей соответственно, к другим входам которых соответственно приложены напряжения ΔU₁ и ΔU₂, запомненные на первом 14 и втором 15 конденсаторах. В результате на выходе первого 18 и второго 19 вычитающих усилителей получаем:

Напряжения с выходов первого 18 и второго 19 вычитающих усилителей поступают на информационные входы первого 20 и второго 21 модуляторов, которые по сигналу с выхода порогового блока 22 формируют на своих выходах напряжения, пропорциональные sinα_i и cosα_i, в виде меандра с частотой опорного напряжения, поступающего на вход порогового блока. Третий 16 и четвертый 17 конденсаторы служат для поддержания выходных напряжений, пропорциональных синусу и косинусу угла, на момент записи/коррекции входной информации N_вxi.At the end of the recording pulse C _{i, the} converter goes into operating mode, i.e., according to the signal through the element NOT 3 (

) the outputs of the second 2 registers are set to the third (high-impedance) state, and the outputs of the first 1 register are connected to the input of block 4 of the functional transformation of the angle code into the sine and cosine codes. By the same signal from the output of the element NOT 3 (

) the third 12 and fourth 13 keys are closed, and the first 10 and second 11 keys are open by control signals from the first and second outputs of counter 9. Block 4 of the functional conversion of the angle code into the sine and cosine code converts the input code recorded from the external device into the first 1 register, into a sine and cosine code, and the first 5 and second 6 digital-to-analog converters perform the operation of multiplying the reference voltage from the source 7, applied to their analog inputs, by digital codes, attached to their digital inputs from the output of the unit 4 pounds conversion of the angle code into the sine and cosine codes, respectively, resulting in:

The voltages from the outputs of the first 5 and second 6 digital-to-analog converters through the closed third 12 and fourth 13 switches, respectively, go to one of the inputs of the first 18 and second 19 summing amplifiers, respectively, to the other inputs of which are respectively applied the voltages ΔU ₁ and ΔU ₂ stored on the first 14 and the second 15 capacitors. As a result, at the output of the first 18 and second 19 subtracting amplifiers, we obtain:

The voltages from the outputs of the first 18 and second 19 subtracting amplifiers are supplied to the information inputs of the first 20 and second 21 modulators, which, upon a signal from the output of the threshold block 22, generate at their outputs voltage proportional to sinα _i and cosα _i , in the form of a meander with the frequency of the reference voltage, entering the threshold block input. The third 16 and fourth 17 capacitors serve to maintain output voltages proportional to the sine and cosine of the angle at the time of recording / correction of the input information N _xi .

 Thus, the introduction into the functional converter of the angle code into sine-cosine voltages of the first and second registers, the second digital-to-analog converter, the block of functional conversion of the angle code into the sine and cosine code, the first, second, third and fourth keys, the first and second subtractive amplifiers, the first and second modulators and the threshold block can significantly increase the accuracy characteristics of the Converter and expand its functionality.

Claims (1)

 A functional converter of the angle code into sine-cosine voltages, containing the first digital-to-analog converter, the analog input of which is connected to the output of the reference voltage source, four storage elements made on capacitors, one of the plates of which are combined and connected to the zero potential bus, a pulse generator, the output of which connected to the counting input of the counter, the input "resolution of the account" which is connected to the output of the element NOT, the input of which is connected to the sync input of the converter characterized in that a second digital-to-analog converter, a functional block for converting the angle code into a sine and cosine code, first, second, third and fourth keys, first and second subtracting amplifiers, first and second modulators, a threshold block, first and second registers are introduced into it, the information inputs of the first of which are the input of the angle code of the transducer, the information inputs of the second are connected to the zero potential bus, the recording inputs are combined and connected to the shutdown input of the output of the first register and the input NOT element, and the outputs are combined and connected to the input of the functional block of the angle code into the sine and cosine code, the first and second outputs of which are connected respectively to the digital inputs of the first and second digital-to-analog converters, the analog input of the second of which is connected to the analog input of the first digital-to-analog converter, the first output of the counter is connected to the control input of the first key, and the second output is connected to the control input of the second key and the input "direct / inverse" of the second register, the input is "off the output of which is connected to the control inputs of the third and fourth keys and connected to the output of the element NOT, the inputs of the first and third keys are combined and connected to the output of the first digital-to-analog converter, and the outputs are connected respectively to the first input of the first subtracting amplifier, another lining of the first capacitor, and the second input the first subtracting amplifier and another lining of the third capacitor, the inputs of the second and fourth keys are combined and connected to the output of the second digital-to-analog converter, and the outputs are connected respectively to the first input of the second subtracting amplifier, another lining of the second capacitor, the second input of the second subtracting amplifier and another lining of the fourth capacitor, the outputs of the first and second subtracting amplifiers are connected respectively to the information inputs of the first and second modulators, the outputs of which are respectively outputs of the sine and cosine voltage of the converter, and the control inputs are combined and connected to the output of the threshold block, the input of which is the input reference variable reference voltage converter.

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