What is a buzzer and how can it be used?
The word 'buzzer' came to be used for a whole range of devices because of the rasping noise made by them. Buzzers can be of two main types – magnetic and piezoelectric disk buzzers, each kind used for a specific purpose. Buzzers are commonly used for annunciator panels (in planes, factories etc), game shows (to signal the answer was correct or wrong), cars, sporting events to signal the end or the beginning of a period and plenty of household appliances (electric oven, microwave ovens, dishwashers etc.). A buzzer consists of switches or sensors, each one of then connected in a certain manner to a sounding board or unit. The control unit is responsible for interpreting the buttons that are pushed, triggering a sound warning, usually a beeping or buzzing sound. These days, there can be a touch sensor panel instead of buttons, but the way it works is always the same.
What kinds of buzzers can there be?
The operating voltage may range from 3V to 220V for a piezo buzzer and from 1.5V to 24V for a magnetic buzzer. However, in order to get a better sound pressure level, there are recommended voltage numbers, for instance 9V for a piezo buzzer. In terms of current consumption, piezo buzzers are more economical, consuming only a few mill amperes, while magnetic buzzers consume a few dozen mill amperes up to hundreds of mill amperes when it starts working. Magnetic buzzers are typically smaller than piezoelectric ones, their size may vary from 7 mm to 25 mm. The dimensions of a piezo buzzer may start at 12 mm. The dimension of the buzzer significantly affects its sound pressure level and the device's frequency. This is why piezo buzzers are most likely to be used for sirens, when very loud sound is required.
Where to get a buzzer?
Buzzers are usually made in China, and the market extends as far as North America, Europe and different parts of Asia. Chinese buzzers comply with the international quality system ISO9001-2000. There is not a certain way a typical buzzer would look like, since a lot depends on the preferences of the customer. There are over a thousand specifications at the moment, and the size of the buzzer is basically completely up to the customer ordering the device, as well as mounting type, current, how much frequency and sound pressure level they want, voltage and drive method. Typical piezo b and magnetic b can be of the following three types: SMD type, self-drive type and external drive type.