![\"Introduction](\"https:\/\/blog.seeedstudio.com\/wp-content\/uploads\/2020\/12\/Introduction-to-Buzzers_-Piezo-and-Magnetic-buzzers-1030x579.png\")
<\/figure><\/div>\n\n\n\nWe will be focusing on two types of buzzers: Piezo and magnetic buzzers since they’re more common as compared to the rest. With that said, let’s look at what will be covered:<\/p>\n\n\n\n
- Overview of Buzzers<\/li>
- Transducers and Indicators<\/li>
- Key Specifications <\/li>
- Applications of Buzzers<\/li>
- Projects with Buzzers<\/li><\/ul>\n\n\n\n
\n\n\n\nOverview of Buzzers<\/h2>\n\n\n\n
What are buzzers?<\/h3>\n\n\n\n
![\"\"](\"https:\/\/i.pinimg.com\/originals\/69\/5a\/b3\/695ab341d4c3296dcbe67a7079d7100f.png\")
A Piezo buzzer
Ref: Pinterest<\/a><\/figcaption><\/figure><\/div>\n\n\n\nBuzzers are electric sounding devices that generate sounds. Typically powered by DC voltage, they can be categorised as Piezo buzzer and magnetic buzzer. They come in different designs and uses as well, and based on that, they can produce different sounds!<\/p>\n\n\n\n
<\/div>\n\n\n\nStructure of the buzzers<\/h3>\n\n\n\n
There’s a difference in the working principle for Piezo and magnetic. Thus, we will first look at the difference in their structure:<\/p>\n\n\n\n
Piezo Buzzer<\/h4>\n\n\n\n
![\"\"](\"https:\/\/www.cuidevices.com\/product-spotlight-templates\/piezo-and-magnetic-buzzers\/img\/6.png\")
Ref: cuidevices<\/a><\/figcaption><\/figure><\/div>\n\n\n\n As its name suggests, a Piezo-type buzzer’s core is the piezoelectric element. The piezoelectric element is made out of piezoelectric ceramic as well as the metal plate, they are held together in or piece by the adhesive. <\/p>\n\n\n\n
<\/div>\n\n\n\nMagnetic buzzer<\/h4>\n\n\n\n
![\"\"\/](\"https:\/\/www.cuidevices.com\/product-spotlight-templates\/piezo-and-magnetic-buzzers\/img\/9.png\")
Ref: cuidevices<\/a><\/figcaption><\/figure><\/div>\n\n\n\n As for the magnetic buzzer, it is mainly composed of the magnet, coil and the vibrating disk which is a ferromagnetic disk. This particular magnetic buzzer is an indicator which has the transistor.<\/p>\n\n\n\n
<\/div>\n\n\n\nWorking Principle of the buzzers<\/h3>\n\n\n\n
Now that we’ve had a better look at Piezo and magnetic buzzers’ structures, we can move on to how they actually work:<\/p>\n\n\n\n
Piezo buzzer<\/h4>\n\n\n\n
![\"\"](\"https:\/\/www.cuidevices.com\/product-spotlight-templates\/piezo-and-magnetic-buzzers\/img\/7.png\")
Ref: cuidevices<\/a><\/figcaption><\/figure><\/div>\n\n\n\n Due to the piezoelectric material, when an AC is passed through it, it’ll shrink and expand. This would then cause a vibration which would produce sound waves as you can see from the diagram.<\/p>\n\n\n\n
<\/div>\n\n\n\nMagnetic buzzer<\/h4>\n\n\n\n
![\"\"\/](\"https:\/\/www.cuidevices.com\/product-spotlight-templates\/piezo-and-magnetic-buzzers\/img\/10.png\")
Ref: cuidevices<\/a><\/figcaption><\/figure><\/div>\n\n\n\n In a magnetic buzzer, the current will be driven through the coil of wire and cause the vibrating disk to be attracted to it. The movement of the disk would produce the sound and it’ll return to its original state when there no current flowing through the coil of wire.<\/p>\n\n\n\n
<\/div>\n\n\n\nVariants of buzzers<\/h3>\n\n\n\n
Apart from the two main types of buzzers, they each also have sub-categories and other types of buzzers as well! So let’s take a brief look at them.<\/p>\n\n\n\n
Electromagnetic buzzers<\/h4>\n\n\n\n
Ref: bestartech<\/a><\/figcaption><\/figure><\/div>\n\n\n\n An electromagnetic buzzer consists of an oscillator, solenoid coil, magnet, vibration diaphragm, housing etc. Pretty much works the same as a magnetic buzzer, where they produce sound through magnetism, with a frequency of 2 kHz.<\/p>\n\n\n\n
<\/div>\n\n\n\nMechanical buzzers<\/h4>\n\n\n\n
![\"\"](\"https:\/\/cdn.shopify.com\/s\/files\/1\/2640\/3158\/products\/Squishy-Circuits_Mechanical-Buzzer.jpg?v=1525723120\")
Ref: squishycircuits<\/a><\/figcaption><\/figure><\/div>\n\n\n\n Mechanical buzzers are technically subcategories of electromagnetic buzzers, thus they consist of somewhat the same components. But what’s different is that the vibrating buzzer is mounted on the outer casing, instead of internally. <\/p>\n\n\n\n
<\/div>\n\n\n\nElectromechanical buzzers<\/h4>\n\n\n\n
![\"\"\/](\"https:\/\/www.futurlec.com\/Pictures\/Package\/SMBUZZER_200.jpg\")
Ref: futurtec<\/a><\/figcaption><\/figure><\/div>\n\n\n\n Electromechanical buzzers are made out of electromagnet and bare metal disc. Works the same way as an electromagnetic and magnetic buzzer, it produces sound through the movement of the disc and magnetism.<\/p>\n\n\n\n
\n\n\n\nTransducers and Indicators<\/h2>\n\n\n\n
Buzzers are actually designed to operate as transducers or indicators when they’re used in circuits. However, there are advantages and disadvantages when it comes to using indicators or transducers. So let’s look at each of their characteristics and differences:<\/p>\n\n\n\n
![\"\"](\"https:\/\/www.cuidevices.com\/product-spotlight-templates\/piezo-and-magnetic-buzzers\/img\/8.png\")
Ref: cuidevices<\/a><\/figcaption><\/figure><\/div>\n\n\n\n Transducers<\/h3>\n\n\n\n
- An external driving circuit required<\/li>
- Able to personalise frequencies or select multiple frequencies<\/li>
- Complex to design-in<\/li><\/ul>\n\n\n\n<\/div>\n\n\n\n
Indicators<\/h3>\n\n\n\n
- Has a built-in driving circuit<\/li>
- Unable to select your frequencies, fixed<\/li>
- Easy to design-in<\/li><\/ul>\n\n\n\n<\/div>\n\n\n\n
Despite their differences, both transducers and indicators are able to produce continuous tones<\/em> and slow\/fast pulse sounds<\/em>. <\/p>\n\n\n\n
However, to do produce continuous tone, transducers need to supply a continuous fixed frequency square wave wile indicators need to supply continuous DC voltage. To produce slow\/fast pulse sound, transducers need to supply square wave pulses of fixed frequency, while indicators to be alternatively switched on and off by applying PWM.<\/p>\n\n\n\n
\n\n\n\nKey specifications of buzzers<\/h2>\n\n\n\n
- Type of buzzer<\/strong> – As we mentioned previously, there are two types of buzzers when used in circuits; transducers and indicators. Both have their different uses so pick your poison!<\/li>
- Sound Pressure Level<\/strong> (SPL) – The deviation from atmospheric pressure caused by the sound wave. SPL is useful when comparing two different audio output, this would then indicate which is louder.<\/li>
- Resonant Frequency<\/strong> – Refers to the frequency in which the buzzer vibrates.<\/li>
- Frequency Response<\/strong> – A buzzer has different SPL for different frequencies, that also means that a buzzer produces different frequencies at different loudness. <\/li>
- Operating Voltage<\/strong> – Piezo buzzers generally have a wider range of operating voltage while magnetic buzzers have a narrower operating voltage.<\/li>
- Impedance – Refers to the electrical impedance, the ratio of an applied voltage to the current. This also varies with frequency.<\/li><\/ul>\n\n\n\n
\n\n\n\nApplications of buzzers<\/h2>\n\n\n\n
Electrical fire alarm<\/h3>\n\n\n\n
![\"\"](\"https:\/\/www.firetronics.com.sg\/wp-content\/uploads\/2020\/05\/photo-rp-call-points-563x563-1-300x300.jpg\")
Ref: firetronics<\/figcaption><\/figure><\/div>\n\n\n\n The fire alarm will only sound when a fire broke out so it’ll need to be loud and alarming to evacuate the people. Thus, a fire alarm would generally use s piezo buzzers. If you’re interested in making your own fire alarm, do check out our project below!<\/p>\n\n\n\n
<\/div>\n\n\n\nMicrowave oven<\/h3>\n\n\n\n
![\"\"](\"https:\/\/www.thespruce.com\/thmb\/GEzG5HRNs8XWj-Epen27ACALMq4=\/1975x1481\/smart\/filters:no_upscale()\/GettyImages-92928577-5a5e5ee45b6e240038e096f0.jpg\")
Ref: the spruce<\/a><\/figcaption><\/figure><\/div>\n\n\n\n I’m sure almost everyone has used a microwave oven before, where you set the timer and once the time is up, it’ll start beeping. Thus, a microwave oven uses a piezo buzzer as well just like the previous fire alarm. Since its purpose is to notify the user.<\/p>\n\n\n\n
\n\n\n\nBefore we jump into the fun projects you can do with buzzers, if you’re looking for a buzzer to experiment, Seeed does offer buzzers so do check it out if you’re interested!<\/p>\n\n\n\n
Grove – Piezo Buzzer\/Active Buzzer<\/a><\/h3>\n\n\n\n
![\"\"](\"https:\/\/static-cdn.seeedstudio.com\/media\/catalog\/product\/cache\/9d0ce51a71ce6a79dfa2a98d65a0f0bd\/h\/t\/httpsstatics3.seeedstudio.comseeedfile2018-08bazaar897330_2.jpg\")
<\/figure><\/div>\n\n\n\nOur Grove piezo buzzer makes it easy for anyone who’s interested to learn, as it simplifies the prototyping process with no soldering, or jumpers required! It has a resonant frequency of 2300\u00b1300Hz, sounds output of \u226585dB.<\/p>\n\n\n\n
Here, we’re recommending the piezo buzzer since it is more versatile. Though if you’re interested in passive buzzer, do check out this and it is a Grove as well:<\/p>\n\n\n\n
Grove – Passive Buzzer<\/a><\/h4>\n\n\n\n
![\"\"](\"https:\/\/static-cdn.seeedstudio.com\/media\/catalog\/product\/cache\/9d0ce51a71ce6a79dfa2a98d65a0f0bd\/1\/0\/107020109_5_.png\")
<\/figure><\/div>\n\n\n\nWith that said, let’s move on to our projects!<\/p>\n\n\n\n
<\/div>\n\n\n\nProjects with buzzers<\/h2>\n\n\n\n
How to Make a Fire Alarm<\/a><\/h3>\n\n\n\n
- Sound Pressure Level<\/strong> (SPL) – The deviation from atmospheric pressure caused by the sound wave. SPL is useful when comparing two different audio output, this would then indicate which is louder.<\/li>
- Type of buzzer<\/strong> – As we mentioned previously, there are two types of buzzers when used in circuits; transducers and indicators. Both have their different uses so pick your poison!<\/li>