## 5 Simulation of the f/N Converter Working in Adaptive Mode
The clock frequency of the f/N converter was set to \(2f_{0}\) to simulate the processing in the whole range. As a result, the regularity of the shape of the error curve \(\delta_{\Sigma}\) increased in relation to the simulation shown in Figure 16; unfortunately, the error value remained at the same level. Doubling the frequency forced the counter to operate faster. The running value of \(N_{xi}\) changed in the range of \(342\div 13313\). It can be concluded that the excessive and arbitrary increase in the frequency of the clock signal generator in the frequency-to-code converter in the incorrectly selected range  
Figure 17: The results of the simulation of sinusoidal test wave processing by the f/N converter while forcing the period of the clock signal \(2T_{0}\). Figure 18: Results of the simulation of test signal processing for the clock signal period of the f/N converter with a value of \(0.5T_{0}\). of processed frequencies of the tested signal increases the demand for the counter capacity and does not give noticeable advantages in accuracy processing. The presented simulation results for the test signal given in the article positively verify the assumptions of the method and confirm its effectiveness. It is known that the accuracy of processing and the results of information processing in the discussed system depend on the parameters of the signal \(x(t)\) and the counter capacity of the \"frequency-code\" converter. As the example of the resultant error plot shows (Figure 5), depending on the frequency of the signal \(x(t)\) and the range of the period change \(T_{xi}\), different settings will be required to achieve an optimal compromise between the length of the period T0 and the capacity of the counter necessary to process the maximum required period \(T_{xi}\). For a waveform \(x(t)\) with different parameters, required conversion range, and required f/N converter counter volume, the threshold settings should be calculated each time, taking into account the maximum value of the conversion error occurring for the maximum frequency of the signal \(x(t)\) at the ends of the conversion range of the periods \(T_{xi}\). It is reasonable to ask about the practical application of a \"frequency-to-code\" converter using a counter circuit to process successive periods of a variable frequency signal. The presented structure and method can be used, for example, in the case of the need to process the rotational speed and irregularity of engine rotation by means of a rotary-pulse converter [36]. Such a circuit directly produces a variable frequency signal. To convert it into a voltage signal for the conversion to digital form by an \"analog-to-digital\" converter would be to add another processing block generating additional errors. Other examples of transducers that directly produce a variable frequency signal include the string transducer [37] and the paddle flow transducer [38]. Moreover, in these cases, the presented direct conversion of frequency into numerical values can be advantageous. Of course, if necessary, the discussed solution can be used to process any variable frequency waveforms, e.g., from the output signals of popular \"voltage-to-frequency\" transducers.