METHOD TO MEASURE NOMINAL FREQUENCY OF SINUSOIDAL SIGNALS AND DEVICE FOR ITS REALISATION Russian patent published in 2013 - IPC G01R23/00 

FIELD: measurement equipment.

SUBSTANCE: method to measure nominal frequency of sinusoidal signals contemplates realisation of tuning of measured nominal frequency with a phase changer controlled by a sawtooth voltage generator. Tuning is carried out until equality of phases with a frequency that arrives directly to the second input of the comparator, the actuation time of which is proportionate to the number of pulses measured by a counter and processed by a microcontroller. At the same time the phase changer comprises RC-links, in which the role of capacitance C is played by capacitor diodes, and the microcontroller comprises a program that provides for the possibility to calibrate different types of sensors for linearisation of dependences of values of physical parameters on frequency. Results of measurements are displayed on an indicator. The device for measurement of nominal frequency of sinusoidal signals comprises a generator of reference frequency, a key, an "AND" circuit, a pulse counter, an indication unit, a microcontroller, the input of which is connected to the output of the pulse counter, and the output - with the indicator, a phase comparator, a gate multivibrator, which starts the generator of sawtooth voltage, which controls the phase changer until equality of phases on the comparator.

EFFECT: provision of high reliability, accuracy of the method, efficiency and universality of application.

2 cl, 3 dwg