Here, a circuit was built in order to test the method presented in this paper. Two frequency generators were used to generate f0 and fx. The prototype circuit is shown in Fig. 9.
| Standard frequency, f0 |
| Desired frequency, fX |
| Standard frequency counter |
| Desired frequency counter |
| Display |
| Main circuit. |
Fig.9. Frequency counter prototype test circuit
There are four circuit boards: two counters, a main circuit and a display. The main circuit board is the control of the entire to the system. It contains the buttons for starting and stopping besides of the connections for the frequencies f0 and fx conjuncted at the AND-gate.
The circuit was tested in a wide range of frequencies and the difference between the value measured by an oscilloscope and the one measured by the prototype is very small, see Fig. 10a and Fig. 10b respectively. The periods quantity of the prototype was 60 (Fig. 10b).
a)
b)
Fig.10. Measured values: a) Oscilloscope; b) Prototype circuit