Easy way to differentiate between active and passive buzzer

Easy ways to differentiate between active and passive buzzers.

The fundamental difference between an active buzzer and a passive buzzer is that the products have different requirements for the input signal; the ideal signal for an active buzzer to work is DC, which is usually labeled as VDC, VDD, etc. Because there is a simple oscillation circuit inside the buzzer, it can convert the constant DC current into a certain frequency pulse signal, and the alternating magnetic field from the surface real out, driving the molybdenum piece to vibrate and pronounce. However, some active buzzers can also work under specific AC signals, but the voltage and frequency of AC signals are very demanding, so this mode of operation is generally not used.

Passive buzzer does not have internal driving circuit, some companies and factories call it an audible buzzer, and the national standard is called a sound buzzer. Passive buzzer works with the ideal signal square wave. If given a pre-DC signal buzzer is not responsive because the magnetic circuit is constant and the molybdenum piece cannot vibrate to pronounce.

Easy way to distinguish active electromagnetic buzzer and passive electromagnetic buzzer

I. Visual inspection.

Take ZL-DCW12085-16-2015P-6.5 and ZL-DCY12095-2305P-7.6 for comparison, where "W" stands for passive and "Y" stands for active.

The shape of the former is 12*8.5, the latter is 12*9.5, both are very similar, such as the two buzzer pin county placed up, you can see that there is a green circuit board is a passive buzzer, no circuit board and closed with black plastic is an active buzzer.

However, this is only a preliminary criterion for judgment, not the only one. If the ZL-YDW1003-5205W is added, it is more complicated to identify, its size is 10*3, this is the smallest piezoelectric passive buzzer on the market.

As the market continues to develop needs, the quality requirements are also increasingly high, and now many manufacturers need 12MM buzzer needs to be sealed at the bottom, in order to its performance stability and prevent the core off and other undesirable situations, so, visual inspection is only the initial identification method.

Here is another method -

Second, multimeter test.

Use the multimeter resistance file Rxl file test: with the black meter pen connected to the buzzer "+" pin, the red meter pen on the other pin touched back and forth, if the trigger out of the click, click sound and resistance of only 8Ω (or 16Ω) is a passive buzzer; if you can issue a continuous sound, and resistance of several hundred ohms or more, is the active buzzer.

Third, the DC voltage test.

General 12MM passive general voltage is 1.5V, active electromagnetic buzzer general voltage of 1.5, 3.0, 5.0, 9.0, 12V, with DC voltage input corresponding voltage (can be adjusted from small to large), the frequency is about 2.7KHZ, can directly ring for the active electromagnetic buzzer, not directly ring, the need for a square wave to drive to ring for passive electromagnetic buzzer