There are many kinds and specifications of buzzers, so you need to know a few parameters (voltage, current, drive mode, size, connection / fixing mode), and more importantly, the sound you want to get (sound pressure, frequency).
Working Voltage: Electromagnetic buzzer, from 1.5 to 24 V, piezoelectric type from 3V to 220V are feasible, but the general piezoelectric or more than 9V voltage is recommended to obtain a larger sound.
Consumption Current: Electromagnetic type according to the voltage of different, from tens to hundreds of milliamperes, piezoelectric type on more power-saving, milliamperes can be normal operation, and in the buzzer start, instantaneous consumption of about three times the current,
Drive mode: Both buzzers have self-excited type, as long as connected with direct current (DC) can sound, because the built-in drive circuit in the buzzer, because of the different principle of action, electromagnetic buzzer to use 1/2 square wave to drive, piezoelectric square wave, in order to have a better sound output.
Size:? The size of the buzzer will affect the volume, frequency, electromagnetic minimum from 7 mm to 25 mm maximum, piezoelectric type from 12 mm to 50 mm or more have.
Connection: There are usually plug (DIP), wire (Wire), SMD, piezoelectric large size and locking screw. Sound pressure: The buzzer usually takes the distance of 10 cm as the test standard, the distance doubles, will attenuate about 6 dB, otherwise the distance will increase by 6 dB, electromagnetic buzzer can reach the level of 85 dB/10 cm, piezoelectric buzzer can do very loud, most of the common alarms are made of piezoelectric buzzer.
For more information, you can visit Dongguan's voice chat website or consult 13559793345. Sound Chang Electronics focuses on the production and research of buzzer and nebulizer products, and always strives to create safe, stable and conform to national standards certification products.