How to Choose and Buy the Buzzer?
There are many different kinds of buzzer to choose, first we need to know a few parameters, such as voltage, current, drive method, dimension, mounting type, and the most important thing is how much SPL and frequency we want.
Operating voltage: Magnetic buzzer, from 1.5 to 24 v, piezoelectric from 3 v to 220 v is feasible, but general piezoelectric or suggest that there are more than 9 v voltage, to gain a greater voice.
According to the difference of current consumption: electromagnetic, from dozens to hundreds of milliampere, piezoelectric was far more save electricity, a few milliampere can normal movement, and the buzzer starts, takes about three times the current moment,
Buzzer have drive mode: Both magnetic and piezo buzzer have self drive type to choose. Because of the internal set drive circuit, the self drive buzzer can emit sound as long as connecting with the direct current. Due to the different work principle, the magnetic buzzer need to be driven by 1/2 square waves, and the piezo buzzer need square waves to get better sound output.
Size: the size of the buzzer will affect the size of the SPL, high and low frequency, the minimum electromagnetic from 7 mm to 25 mm, piezoelectric from 12 mm to 50 mm, or more generally.
Connection mode: DIP,Wire, SMD, and screwed type for big piezo buzzer are usually seen.
Sound pressure:The distance of 10 cm is usually as test standard, the distance double, the SPLwill decay about 6 dB;oppositely, the SPL will increase 6 dB when the distance is shortened by one time. The SPL of magnetic buzzer can reach to 85 dB/10 cm, piezo buzzer can make very loud sound, common siren, mostly are made from piezo buzzer.
