You will need
  • Alternator, capacitor, inductance tester
Alternating current is generated in the frame of the conductor rotating in a constant magnetic field with a certain angular velocity. Since angular velocity is directly proportional to the rotational speed, increase or decrease the frequency of the AC current, reducing or increasing the rotational speed of the generator coils. For example, increasing the rotational speed of the generator coils in 2 times, will receive an increase in the frequency of the alternating current by the same factor.
If AC voltage is applied in the network, its frequency can be changed using in the circuit of an inductor and a capacitor. Install in the network of an inductor and a capacitor, connecting them in parallel. Such a resonant circuit will create their own frequency. In order to calculate with a tester that is configured for measurement of inductance, find the value for this particular coil. After that, determine the capacitance of the capacitor in the circuit using the same tester, just with the settings for measuring capacitance.
Plug the system into an AC power source, while the active resistance should be negligible. This oscillating circuit will create circuit's natural frequency, which is the cause of capacitive and inductive reactance.
To find its value:
1. Find the product of the inductance values and the capacitance measured with a tester.

2. From the value obtained in paragraph 1, extract the square root.

3. The result multiply by the number of 6.28.

4. The number 1 will divide the value obtained in step 3.
If you change the frequency of the current need to consider the fact that if the network frequency and the frequency of the circuit coincide, there will be phenomenon of resonance in which the maximum values of current and EMF will increase significantly and the circuit can burn out.