One cycle of a sine wave (such as the mains power voltage) consists of two half cycles (often called positive and negative in electronics).

Is there a (preferably one-word) term to refer to such a sine wave half cycle?

I have seen the term half sine wave, but it is hardly better. And besides, I believe this refers to all positive or all negative half cycles in aggregate, not to individual half cycles.

I am especially interested in this in regards to the mains power.

  • 6
    \$\begingroup\$ I'd call it a positive half cycle. \$\endgroup\$
    – Andy aka
    Commented Mar 23, 2021 at 17:17
  • \$\begingroup\$ "Swing" sounds appropriate. Pity no one is using it :) \$\endgroup\$
    – Eugene Sh.
    Commented Mar 23, 2021 at 17:21
  • \$\begingroup\$ I think "positive half cycle" is good. Brainstorming alternatives: maybe "first pi"? \$\endgroup\$
    – KD9PDP
    Commented Mar 23, 2021 at 18:04
  • \$\begingroup\$ expanding on @EugeneSh. comment ... upswing \$\endgroup\$
    – jsotola
    Commented Mar 23, 2021 at 18:37

3 Answers 3


As is often the case, it depends on context. If the entire waveform is present, but you you want to point out a particular half-cycle, you should say "positive half cycle" or negative half-cycle. If you have a zero-crossing switch that lets through a half cycle out of every 5 cycles then you have a series of "sinusoidal pulses" or a series of positive or negative "sinusoidal pulses." You might shorten that to "sine pulse."

  • \$\begingroup\$ +1 for sine pulse \$\endgroup\$
    – Neil_UK
    Commented Mar 23, 2021 at 19:36

I'm not a aware of a specific term, but if you introduce it you can use you can invent your own terminology, eg "hump" "sinus" "pulse".


I really like the sound of a sine pulse that @CharlesCowie suggested. Unfortunately, it seems a little ambiguous to me whether it refers to a half sine cycle or a full sine cycle.

I propose a sine lobe. It does not sound as good as the sine pulse but I believe is less ambiguous.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.