SU974574A1 - Frequency-to-voltage converter - Google Patents

Description

The invention relates to automatic control devices and can be used in information and measurement systems of automation and computing.

A known frequency converter operates according to the principle of counting the number of periods of a frequency to be converted during a reference time interval Ij.

Its disadvantage is low speed.

A frequency to voltage converter is known that contains a driver of control signals, a reference oscillator, a pulse counter, the counting input of which is connected to the output of the reference oscillator, and the inputs of setting to zero and counting, respectively, to the first and second outputs of the driver of control signals, and analog converter, to the analog input of which the output of the source of the reference voltage is 2}.

Its disadvantages are due to the fact that in order to obtain a linear conversion function, the digital-to-analog converter must be inversely proportional, and consist in reduced reliability and insufficient.

accuracy, since with equal material costs the inversely proportional digital-analog converter is less accurate than the magnetic one.

The aim of the invention is to increase accuracy and reliability.

The goal is achieved by the fact that the frequency converter is a voltage containing a driver

Claims (2)

10 control signals, a reference oscillator, a pulse counter, the counting input of which is connected to the output of the reference oscillator, and the inputs set to zero and the counting resolution is responsible for the first and second outputs of the control signal generator, and digital-analog converter; To the analog input of which the output of the source of this 20 volt voltage is connected, a code multiplication unit is introduced, the inputs of which are connected to the output of the pulse counter and the input of the digital-analog converter, the setpoint block, the comparator of codes, the inputs which are connected to the outputs of the setpoint block and the code multiplication block, and the sequential approximation register, the first and second inputs of which are connected respectively to the outputs of the code comparator and the reference oscillator, and the output to the input of the digital-analog converter. The drawing shows the functional diagram of the converter to voltage. It contains the driver 1 of the control signals, the supporting generator 2, the pulse counter 3, the counting input of which is connected to the output of the reference generator 2, and the inputs of setting to zero and counting resolution, respectively, to the first and second output of the driver 1, the multiplying unit 4, whose input connected to the output of the counter 3, and a control input to the output of the imager 1. The output of block 4 is connected to the first input of the code comparator 5, to the second input of which the output of the set-up block 6 is connected. The outputs of the comparator 5 and generator 2 are connected to the inputs the serial approximation register 7, the output of which is connected to the inputs of block 4 and digital-to-analog conversion of bodies 8. The output of reference voltage source 9 is connected to the analog input of digital-to-analog converter 8. The converter operates as follows. The input signal of the measured frequency is fed to the driver of the control signals 1. The first inverse signal from the coupling of the spreader 1 arrives at the counter 3, resetting it to zero, the second inverse signal of the pc13 resolves the filling of the counter 3 with the reference frequency, and the third non-inverse signal records the contents of the counter 3 into multiplication unit 4. Reference generator 2 generates signals: a reference frequency (d5) for filling the counter 3 J of the clock frequency C i.). to control the serial approximation register, 7. A code from counter 3, proportional to the generated period T of the input frequency f, is fed to multiplication unit 4 and further to comparator 5, where the digital code comparison is performed; coming from multiplier 4, and Q-X code coming from setpoint block b. The code equality signal from comparator 5 controls the tip clock frequency in the sequential approximation register 7, which produces the parallel code Z inverse to the code for period T After the linear converter of this code by digital-to-analog converter 8, we obtain the output voltage of the frequency to voltage converter, which can be determined by the expression. In the proposed device, a standard linear digital-to-analog converter can be used, thereby improving the accuracy of the converter and reliability in his device. Claims of the Inverter Frequency to voltage converter containing a driver of control signals, a reference generator, a pulse counter, the counting input of which is connected to the output of the reference generator, and the inputs of setting to zero and the resolution of the counter corresponding to the first and second outputs (driver of the control signals and a digital-to-analog converter, to the analog input of which the output of the source of the reference voltage is connected, is also distinguished by the fact that, in order to increase accuracy and reliability, a block is introduced into it more than and codes whose inputs are connected to the output of a pulse counter and the input of a D / A converter, a setting block, a code comparator whose inputs are connected to the outputs of a setting block and a code multiplication unit, and a serial approximation register, the first and second inputs of which are connected respectively to the outputs of a code comparator and the reference generator, and the output - to the input of the digital-to-analog converter.Sources of information taken into account during the examination 1. Reference book on radio-electronic devices. Ed. DPLinde, m ;, Energie, 1978 p. 420-421. 2. Measuring equipment, 1968, No. 8, p. 69; FIG. 2 (prototype). At: I Mr N (/ five GU A-J V-n & (/. Z L G x at x