How to distinguish an active buzzer from a passive buzzer?

(Comprehensive)
First, it is worth paying attention to: the "source" here is not the power supply, but the shock source.
That is to say, the active buzzer is internally with an oscillation source, so as soon as the power is applied, it will call
In general, active buzzers are: the distinction between intermittent and continuous tones;
The passive buzzer does not have an oscillation source inside, so direct current cannot make it directly tweet.
IT MUST BE DRIVEN BY A SQUARE WAVE SIGNAL OF 2-5KHZ TO MAKE IT CHIRP.
Therefore, the active buzzer is often more expensive because it has an additional oscillation circuit part in it.
In layman's terms, a passive buzzer is like a horn, and an active buzzer is like an MP3+ speaker.
The passive buzzer should add a driving signal to produce sound, and the tone can be set by itself;
And the active buzzer already has a circuit inside, and with an oscillation source, giving him a working voltage will make a sound,The tone (frequency) is already fixed and cannot be tuned by itself.