Topics of Interest
In this section we will deal with selected questions about electricity and electronics that were sent to the author from anywhere in the world. Although I may not be able to get a new question every week, you may bookmark this page as it will be updated from time to time.
Would YOU like to think of some topics we could discuss? Please sent them in. In the meantime you may also visit some of the previous topics of interest.
Audio Frequencies
Question: What are the frequencies of some musical notes? Can we calculate an octave and what is its relationship to a higher or lower octave? Answer: That is a good question, because much of the technology is heavily intertwined with frequencies. So let us look at musical frequencies first. Every note has a different frequency. For "C",
for example, this is 523.3 Hz. For our musically interested: Please note that octaves
are not influenced by the temperament. Octaves are always pure, without
beats, no matter which note. The temperament is used within the octaves.
It allows us to play in any key without having to retune the intruments.
A musical education, apart from other benefits, helps us
often in technological matters. One example comes to mind: Listen to the
pitch of the motor under different load conditions. Listen to the note
of your vacuum cleaner. When it is blocked up the pitch will go up a semitone
ore even more. Remove the blockage and you can prevent the motor from burning
out. Click here a selection of past topics.
Return to the Fact Sheet links. Go to author's home page. Copyright © 1997-2010 Peter Schmedding, Child Development Projects, Canberra, Australia.
When you listen to an orchestra or a band, before they start playing they 'tune' their instrumens. The note they are using is the "A". In fact, this is an international standard and used all over the civilised world. A has a well defined frequency and that is 440 Hz. (Hertz, meaning oscillations per second.) The lower instruments, of course, will tune to an octave below and it is easy to remember that the octave is always a multiple of the previous one. One octave means twice the frequency. One octave down will be half the frequency. For A this is 880 and 220 respectively.