The module is driven by 9012PNP transistor, with fixing bolt holes for easy installation. Pin out for easy wiring

Operating voltage:3.3V-5V
PCB size:3.3cm*1.3cm

VCC external 3.3V-5V voltage (can be directly connected to the 5v microcontroller and 3.3v microcontroller), GND external drive system GND, I/0 external microcontroller IO pins or other audio drive source, repeatedly connected to the low level of the click sound.

Note: The "source" here does not mean the power supply. Rather, it refers to the oscillation source.
Active buzzer has a simple internal oscillator circuit, can be converted to a constant DC into a certain frequency of the pulse signal, the program control is convenient but the frequency is fixed, the microcontroller a high and low level on the
A high or low level of the microcontroller can make it sound.
Passive buzzers and electromagnetic speakers have no internal drive circuit and need to be connected to the audio output circuit in order to produce sound.
circuit to produce sound. If you give a DC signal is not loud, because the magnetic circuit is constant, you must use 2K ~ 5K square wave to drive it. The frequency of the sound can be controlled, so that the effect of "Doraimi Faso Rasi" can be made. In some special cases, it can be multiplexed with LEDs in one control port.