What is the frequency of `30 points
Frequency is to change the frequency ah, see what you are variable frequency equipment.
AC are frequency, China is 50 Hz, is in a second amplitude of 50 times.
To change this frequency, it is necessary to use some electronic components to change the current frequency.
General frequency conversion for the tributary motor speed more. So that some equipment can be stepless.
Principle, see the first floor just fine, copy the more detailed.
frequency conversion
By changing the AC frequency of the way to achieve AC power control technology is called frequency conversion technology