SU886237A1

SU886237A1 - Voltage-to-frequency converter

Info

Publication number: SU886237A1
Application number: SU792709437A
Authority: SU
Inventors: Виктор Алексеевич Прянишников; Анна Михайловна Ланских
Original assignee: Ленинградский Институт Точной Механики И Оптики
Priority date: 1979-01-05
Filing date: 1979-01-05
Publication date: 1981-11-30

Description

1one

Изобретение относитс к цифровым измерительным приборам и может найти применение в аналого-цифровых преобразовател х с промежуточным преобразованием аналоговой величины в частоту следовани импульсов.The invention relates to digital measuring instruments and can be used in analog-to-digital converters with an intermediate conversion of an analog value to a pulse frequency.

Известен преобразователь напр жени в частоту, выполненный на магнитном интегрирующем элементе 1.A voltage-to-frequency converter is known, made on a magnetic integrating element 1.

Недостаток данного преобразовател - пониженна точность.The disadvantage of this converter is low accuracy.

Известен также преобразователь напр жени в частоту, содержгиций магнитный интегрируквдий элемент с двум обмотками, перва иэ которых включена между входной шиной преобразовател и входом операционного усилител , к выходу которого подклао4ek вход первого компаратора и источнй1с образцового напр жени 2J.Also known is a voltage-to-frequency converter, a magnetic integrated element with two windings, the first of which is connected between the input bus of the converter and the input of the operational amplifier, the output of which is the input of the first comparator and the source voltage of the 2J.

Недостатком известного устройства вл етс ограниченный диапазон преобразовани ..A disadvantage of the known device is the limited conversion range.

Цель изобретени - раЬширение диапазона преобразовани .The purpose of the invention is to increase the conversion range.

Поставленна лель достигаетс тем, что в преобразователь напр жени в частоту, содержащий магнитный интегрирующий элемент с двум обмотками, перва из которых включена междуThe supplied Lel is achieved by the fact that a voltage to frequency converter contains a magnetic integrating element with two windings, the first of which is connected between

входной шиной преобразовател и входом операционного усилител , к выходу которого подключен вход первого компаратора и источник образцового напр жени , введены второй компаратор вход которого подключен к выходу операционного усилител , первый RSтриггер , S-вход которого подключен к выходу первого компаратора,а R-вход the input bus of the converter and the input of the operational amplifier, the output of which is connected to the input of the first comparator and the source of the reference voltage, introduced a second comparator whose input is connected to the output of the operational amplifier, the first RS trigger, the S input of which is connected to the output of the first comparator, and the R input

10 к выходу второго компаратора, второй RS-триггер, S-вход которого подключен к выходу второго компаратора, а Н-вход - к выходу первого компаратора , элемент ИЛИ, входы которого подключены к выходам компараторбв, 10 to the output of the second comparator, the second RS trigger, the S-input of which is connected to the output of the second comparator, and the H-input to the output of the first comparator, the OR element whose inputs are connected to the outputs of the comparator,

15 счетный триггер, вход которого подключен к выходу элемента ИЛИ, первый элемент И, входы которого подключены к выходам счетного триггера 15 counting trigger, the input of which is connected to the output of the element OR, the first element AND, whose inputs are connected to the outputs of the counting trigger

Claims

20 and the first RS-flip-flop, the second element And, the inputs of which are connected to the outputs of the counting trigger and the second RS-flip-flop, and the first and second switches, the inputs of which are connected to the source of the reference voltage, the control inputs - respectively to the outputs of the first and second elements And, and the outputs - to the second processing of the magnetic integrating element. The drawing shows the functional electrical circuit of the device. The converter contains a magnetic integrating element 1, the first winding of which is connected to the input of the operational amplifier 2, comparators 3 and 4, whose inputs are connected to the output of amplifier 2, the element OR 5, whose inputs are connected to the outputs of the comparator 3 and 4, and the output to the input of the counting trigger b, RS-three ger 7, S-input of which is connected to the output of comparator 3, and R-input - to the output of comparator 4, RS-flip-flop 8, Z-input of which is connected to the output of comparator 4, and R-input to the comparator output 3, element I-9, whose inputs are connected to the outputs of triggers b and 7 , element 10, the inputs of which are connected to the outputs of flip-flops 6 and 8, switches 11 and 12, the control inputs of which are connected respectively to the outputs of elements 9 and 10, the outputs to the second OBM of the magnetic integrating element 1, and the inputs to the source 13 exemplary voltage. The device works as follows. With an input signal of negative polarity, the output of operational amplifier 2 produces a linearly increasing voltage, the moment of time when this voltage reaches. the threshold level 4- Ujjf, the comparator 3, the pulse, arising at the last output, confirms the zero state of the trigger 8, triggers the trigger 7 into one state and, passing through the element OR 5, sets the counting trigger 6 into one with the The signal from the output of the counting field b at zero state of the trigger 8 does not pass through the element And 10 The signals from the outputs of the triggers b and 7 pass through the element And 9, as a result of which the switch 11 connects the source 13 of the reference voltage element 1 winding. The appearance of a current pulse from source 13 in this winding leads to a linear decrease in voltage at the output of the operational amplifier 2. When this voltage reaches the threshold level of the comparator 4, the pulse that occurs at the output of the latter sets the trigger 8 into one th from the set, the trigger 7 - to zero soeto v1ie and, after passing through OR gate sets counting trigger used in the null state, whereby the through elements 9 and 10, the signals do not pass and the second coil member is disconnected from the source 13 obraztsoogo voltage. The process then repeats at a frequency proportional to the voltage being measured. When a positive voltage converter is applied to the input, all processes occur similarly, with the difference that the comparator 4 is first triggered, after which the signal passes through trigger 8 and element 10 to control switch 12 connecting Source 13 to the second winding of the integrating element 1. Next the whole process is repeated. The proposed device performs the conversion of the input signal of both polarities, as a result of which the conversion range is extended. Claims of the Inverter Voltage-to-frequency converter containing a magnetic integrating element with two windings, of which is connected between the input bus of the converter and the input of the operational amplifier, the output of which is connected to the input of the first comparator and the source of the reference voltage, and that, in order to extend the conversion range, a second comparator is entered into it, the input of which is connected to the output of the operational amplifier, the first RS flip-flop, the S-input of which is connected to the output of the first comparator ora and R input - to the output of the second comparator, the second RS-trigger, the S-input of which is connected to the output of the second comparator, and the R-input to the output of the first comparator, the OR element, whose inputs are connected to the outputs of the comparators, counting trigger, input which is connected to the output of the element OR, the first element is AND, the inputs of which are connected to the outputs of the counting trigger and the first RS-flip-flop, the second element AND, the inputs of which are connected to the outputs of the counting trigger and the second RS-flip-flop, and the first and second switches, the inputs of which are connected to the source of scraper voltage, control inputs, respectively, to the outputs of the first and second I elements, and outputs, to the second winding of the magnetic integrating element. Sources of information taken into account in the examination 1. The author's certificate of the USSR 482892, cl. H 03 K 13 / 20.29.05.72.

2.Pr Nishnikov V.A. Integrating digital DC voltmeters, L., Energie, 1976, p. 144, fig. 3-24 (prototype).