Distinction between Passive / Energetic Buzzers

Many purchasers whom obtained samples by way of our web site usually inquires for assistance on learn how to drive the buzzer, particularly when no sound is generated from buzzers. This downside happens when apply DC to passive sort buzzers. This is quite common case since many individuals don’t use buzzers today just like the 90’s when buzzers have been utilized to cell telephones.

Beneath desk exhibits synonyms utilized in these two kinds of driving strategies.

passive buzzerenergetic buzzer
AC sortDC sortenter sign
exterior pushedinner pushedwhether or not inner oscillating circuit is inclusive or not
audio transduceraudio indicator

<table1 – synonym>

This publish will information you with primary info and benefits/disadvantages of passive/energetic sort buzzers.


1. passive sort buzzer

As you may see in determine 1 beneath, SMD Buzzer produced by Bosan Hitech is a product utilized with electromagnet. When the electrical present flows by way of the coil wound round magnetic yoke(magnetic substance), magnetic power is generated on level A within the figure1 and pulls down the diaphragm situated above, then releases it again to its authentic  place as soon as electrical present drops right down to zero.

<fig. 1 – inner construction of electromagnetic buzzer>


Beneath desk 2 exhibits the vertical displacement of the diaphragm adopted by electrical enter sign.

sort of signelectrical enter waveformdisplacement of diaphragm
sq. wave  
sine wave  

<desk 2>

in case of the primary displacement generated by DC, no sound is obtainable as a result of it doesn’t vibrate diaphragm. In case of ACs within the different hand, these will vibrate diaphragm and this may generate precise sound that we will hear by ears.

Sq. wave is usually utilized in most of digital functions which can be managed by digital circuit and can make it even simpler if PWM management is offered.  Melody from Christmas playing cards or sound of contact wheel from IPods(https://youtu.be/9-mWbV3lZH0) are good examples.


2. energetic sort buzzer

An energetic sort buzzer which incorporates an  oscillation circuit as proven in determine 2 inside is usually used for purchasers who really feel AC management is pointless.

<fig. 2 – astable multivibrator circuit>
picture supply – https://www.electronics-tutorials.ws/waveforms/astable.html

On this case it’s out there to create sound by simply driving direct present in each terminals, however it could actually create just one sort of tone(Primarily 2,400 Hz) as a consequence of limitation of the interior half. It’s usually utilized in functions that simply wants easy sound similar to barcode reader in tremendous markets.

By this circuit person will simply apply DC to the energetic sort and simply generate sound. However it could actually create just one sort of tone(2,400 Hz on the whole) as a result of interior components are fixed. It’s usually utilized in functions that simply wants easy sound similar to barcode reader in tremendous markets


3. execs & cons of each varieties

passive sort

energetic sort

driving problemarduoussimple
valuelowexcessive as a consequence of extra components/processes
response time< 10ms50-200 ms
sound tone accuracy±5 Hz

sound tone equals enter frequency

±300 Hz

consistency of astable multivibrator circuit shouldn’t be good

out there soundvaries by programmingmounted tone
min mounting floor5 x 5 mm212 x 12 mm2

<desk 3>

We, Bosan Hitech Co. Ltd., have its patented design and course of in manufacturing passive sort  buzzers and within the pursuit of profitable market equipment of low value and excessive efficiency buzzers, we assist companies as beneath in title of developer assist

-. free pattern as much as 20 items
-. supply program and circuit utilized in demo equipment

Ought to you’ve gotten any queries, please be at liberty to contact us.


What makes Bosan’s parts have loud level of sound, with plain plastic magnet?

Back in 1990s when its affiliated company – Yulrim Magnet – was supplying magnets to buzzer manufacturer in Korea, Structure of buzzers at that time was not understandable for us, because it was complicated and inefficient. Yulrim Magnet suggested to replace 3-4 parts into one unibody magnet to save those customer’s cost and time but all those attempts was ignored. And this is the beginning of Bosanhitech’s history.

Korean buzzer manufacturers in middle of 1990s were adopting buzzer’s structure led by Japanese competitors. And all the Japanese companies used isotropic Neodymium magnet to drive their buzzers. This Isotropic Neodymium magnet are superior in magnetic force per unit volume. But are not good in making complex structure. This was the point we focused and developed an unibody based buzzer with Anisotropic Ferrite magnet.

external link : the difference between the isotropic magnet and anisotropic magnet

materialIsotropic NeodymiumAnisotropic Ferrite
forming processbondedInjection molded
material costhigh, frustratingLow, stable
magnet flux per unit volume7,200 Gauss2,390 Gauss
complexity of designhardeasy
magnetic material volume used in a buzzer25 mm3150 mm3

As can be understood by above link and table, if the body of a buzzer is made of anisotropic Ferrite magnet, total magnetic force obtainable is higher by appr 2 times comparing to a buzzer that has isotropic Neodymium magnet inside.


A magnetic buzzer has more chance of having louder sound level, if it has stronger magnetic force inside. All of the magnetic buzzers Bosanhitech make have adopted this material / structure in order



to obtain high level of sound and stable level of component cost to comfort customers.(In 2017, the Chinese industry one-sidedly increased the price of neodymium magnet or halted its production, which was a massive blow to the industry, while Bosan Hitech was untouched and came out unaffected)

We will keep this technological improvement to be customer’s satisfaction all the time.



Introducing BSMT-1140T collection

Introducing BSMT-1140T collection,
The Most versatile SMD magnetic transducer within the trade.

From the institution in 1997, our objective has all the time been making SMD magnetic transducers as a significant product within the buzzer trade the place THT sort had been dominating.
After listening to buyer all around the world’s suggestions and getting by in-depth analysis, we lastly developed new SMD magnetic transducer – BSMT-1140T collection – with high versatility defined on this doc.
Please discover out why this half is completely different from others, and make contact with us or go to our sales space.


Lowest priced SMD buzzer in the marketplace

Price Comparability of Buzzers

Within the case of different digital part trade, many shoppers have switched from THT to SMD, as price in utilizing each was on the similar degree. Nonetheless, it was not the case within the buzzer trade but, so there had all the time been a excessive demand for extra inexpensive SMD buzzers from clients.

This was a kind of issues that we’ve got targeted. We deliberate to make half with good efficiency and reliability, on the similar price evaluating to THT sort. To do that, we needed to construct our manufacturing course of from backside to high, to chop out labor price which is kind of costly in Korea.

Although there nonetheless is worth distinction as seen in above chart, we anticipate that there shall be no worries in switching from THT to SMD buzzer sooner or later contemplating the mounting price, productiveness, and failure ratio.


Patented easy construction which brings excessive reliability

An evidence of Structural distinction towards different makers’ buzzer

How does this distinction carry reliability?

A. Easier half, fixed high quality.
As proven in above comparability, Bosan half’s foremost physique is uni-body product of magnet, whereas different elements within the trade is consisted with 2~three subparts which requires bonding/welding.
This straightforward construction guarantees an essential inside think about producing sound to be in excessive quantity. This additionally guarantees that there shall be much less inside deformation because of excessive temperature.

B. Much less elements, much less processes
Since smaller variety of elements are required to construct Bosan’s half, it’s a lot simpler to develop automated machines with excessive effectivity. Bosan has succeeded in growing these 10 years in the past due to the easy construction, and the machines has acquired extra correct every year since then.

C. Un-manned coil winding
In contrast to buzzers from different producer on this trade, Bosan buzzer’s easy construction permits its coil to be immediately wound and soldered within half with full auto machine. With effectively designed machine administration system, all of the coils are wound and soldered with machine accuracy so this half has much less likelihood of getting defected after pick-n-place and reflow course of.


Swiftness and agility

Downside – what is going on within the trade

We obtain inquiry from many shoppers all around the world complaining about former provider’s irresponsible supply. We see this downside arising from the tradition of the Chinese language trade, the place most suppliers choose doing manufacturing and distribution on the similar time.
In different phrases, most of accidents occur as a result of these suppliers ahead product from its competitor.

We have been in the identical state of affairs in addition to these producers years in the past. Investing amenities/equipments for varied sorts of product was not optimistic in most of circumstances. So we needed to import from Chinese language producers and resell to clients.

Answer we’ve got applied

As time goes by nevertheless, we came upon that it was important to have a manufacturing system which might meet agility and reliability on the similar time within the period of commercial booming. So we studied a manufacturing line which might produce from a hatchback to a sedan in a single place, and the implementation was profitable ultimately.

As of 2017 this method is prepared for SMD magnetic transducer, which is the main product of Bosanhitech. The primary product from this method is BSMT-1140T collection which we are going to introduce by this doc and the International Supply commerce present. And after gathering buyer’s requirement by the present and all of the communication, we plan to introduce 2 extra product from 2018.