저희 홈페이지를 통해서 샘플을 받아가시는 많은 분들이 초기구동을 하지 못해 연락을 주시는 경우가 있습니다. 이 문제는 교류/직류타입 버저에 대한 이해가 없기 때문에 발생하며 휴대폰에 버저가 쓰이던 90년대와는 다르게 요즘엔 버저를 사용해보지 않은 분들이 많아서 생기는 현상입니다.

아래 표는 이 두가지 타입을 지칭하는 일반적인 용어들입니다.

명칭 구분기준
교류타입
AC type
직류타입
DC type
입력신호
회로외장형
external driven
회로내장형
internal driven
발진회로 내장여부
passive buzzer active buzzer
audio transducer audio indicator

<표1 – 두 타입을 지칭하는 용어들>

본 포스트에서는 이러한 교류/직류타입 버저에 대한 설명, 구동법 및 장단점에 대해 알아보겠습니다.

 

1. 교류타입

(주)보산하이테크에서 제조하는 마그네틱 버저의 경우 아래 그림1과 같이 전자석을 응용한 제품입니다. 아래 그림1에서 내부 철심에 감겨있는 코일에 전류가 흐르는 순간 그림1의 A 지점에 자력이 발생하여 철심 위의 자성체인 진동판이 당겨지고, 전류가 0이 되면 진동판이 원위치로 돌아가게 됩니다.

<그림 1 – 교류버저의 내부구조>

 

아래 표2는 입력되는 전기신호에 따른 진동판의 시간에 따른 변위(그림1에서 노란화살표로 표시)를 나타낸 것입니다.

입력신호 파형 진동판의 변위
직류
DC
   
구형파
square wave
   
사인파
sine wave
   

<표2 – 입력신호에 따른 진동형태>

 

표1의 우측 파형 중 직류가 입력되는 경우엔 진동판의 변위도 변하지 않아(떨림이 발생하지 않아) 소리가 나지 않고, 구형파/사인파 등의 주기성을 가진 교류가 입력될 경우엔 진동판이 떨림으로 인해 우리가 들을 수 있는 소리가 나게 됩니다.

이런 신호는 대부분 디지탈신호로 제어되는 전자제품의 특성상 사인파보다는 구형파를 이용하는게 일반적이며, PWM제어를 사용할 수 있다면 가장 간단하게 만들어 줄 수 있습니다. 멜로디가 나는 크리스마스카드나 아이팟의 터치휠(링크삽입 : https://youtu.be/9-mWbV3lZH0)소리가 대표적입니다.

 

2. 직류타입

이런 교류제어가 번거롭게 느껴지는 경우를 위하여, 교류버저의 내부에 아래 그림2와 같은 발진회로를 추가한 버저입니다.

<그림2 – 비안정 멀티바이브레이터 회로>
출처 – https://www.electronics-tutorials.ws/waveforms/astable.html

이 경우는 버저의 양단에 직류만 인가해줘도 소리를 얻을 수 있는 대신 내부 부품이 정해져 있기 때문에 한가지 톤(주로 2,400 Hz)의 소리만 얻을 수 있습니다. 소리만 나면 되는 어플리케이션에 주로 사용되며 가장 대표적인 적용예가 마트 계산대의 바코드 리더기입니다.

 

3. 두 타입의 장단점

항목 교류타입 직류타입
구동난이도 어려움 간단함
단가 낮음 부품/공정수 추가로 높음
지연속도 < 10ms 50-200 ms
주파수 오차범위 없음(입력한 주파수대로 소리발생) ±300 Hz(내부부품에 따라 발진회로의 주파수범위의 편차발생)
구현가능한 소리 입력신호에 따라 멜로디 클릭소리등 다양한 소리구성 가능(소스제공가능) 고정톤(주로 2,400 Hz)
최소한 실장면적 5×5 mm2 12×12 mm2

<표 3 – 각 타입의 장단점>

저희 (주)보산하이테크에서는 교류버저의 설계 및 제조에 특화된 특허를 보유중이며, 이와 같은 고성능 저단가 제품의 성공적인 시장적용을 위해 개발자 지원명목으로 아래와 같은 영업대응을 하고 있습니다.

-. 방문 및 데모시연(데모장비 보유)
-. 무료 샘플 제공(최대 20개)
-. 데모장비에 사용된 각종 소리의 소스 프로그램과 회로도

문의사항 있으시면 언제든 연락 바랍니다.

 

th-1

저희 계열사인 yulrim magnet의 자석제조업 초기에 몇 곳의 버저 제조사로부터 자석 납품 의뢰를 받았습니다. 이 자석을 납품하면서 들었던 의문점은 ‘왜 이렇게 비효율 적이며 복잡한 구조를 가지고 있는가’ 였습니다. 이 발상으로부터 bosan hitech의 역사는 시작됩니다.

당시 일본회사를 필두로 한 모든 버저 제조사들은 등방성 네오디뮴 자석(isotropic neodymium magnet)을 사용하여 제품을 만들고 있었습니다. 이 네오디뮴 자석은 단위 체적당 자력의 세기는 월등히 높았지만, 복잡한 형상을 구현하는데는 문제가 많았습니다. 그래서 저희 회사는 이방성 페라이트자석(Anisotropic Ferrite magnet) 으로 일체명 버저를 개발하게 되었습니다.

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

소재 등방성 네오디뮴자석 이방성 페라이트
성형방법 소결/본디드 사출
자재비용 높고 불안정함 2,390 G
단위체적당 자속밀도 7,200 G 2,390 Gauss
형상의 복잡도 낮음 높음
제품에 적용된 자석의 체적 25 mm3 150 mm3
녹발생여부 발생 녹슬지 않음

위 표에서 표기된 바와 같이, 동일한 체적에서 나오는 자력을 비교해 봤을 때는 경쟁사에서 사용하는 자석의 자력이 높지만, 아래 그림과 같이 버저의 몸체를 자석으로 만들게 되었을 경우 체적이 제품에 따라 5-10배 정도 늘어나기 때문에 결과적으로 더 강한 자력을 얻을 수 있게 됩니다.

버저의 경우 자력이 셀수록 큰 소리를 얻는데 유리해집니다. 저희 보산하이테크에서 만드는 모든 버저는 이러한 자재 / 공정을 사용함으로써 고객이 원하는 큰 소리의 제품을 안정적인 가격으로 공급할 수 있는 기술적인 원천을 가지게 되었습니다(2017년에 중국 산업계에서 일방적으로 네오디뮴 자석의 단가를 인상 혹은 생산중단하여 관련 업체가 많은 타격을 보았지만 보산하이테크는 이로 인한 아무 영향을 받지 않았습니다)

이런 기술적인 개선으로 인한 결실을 많은 고객들에게 만족으로 안겨드릴 수 있도록 항상 최선을 다하겠습니다

th001-1

Introducing BSMT-1140T series,
The Most versatile SMD magnetic transducer in the industry.

From the establishment in 1997, our goal has always been making SMD magnetic transducers as a major product in the buzzer industry where THT type had been dominating.
After hearing customer all over the world’s feedback and getting through in-depth research, we finally developed new SMD magnetic transducer – BSMT-1140T series – with top versatility explained in this document.
Please find out why this part is different from others, and contact us or visit our booth.

 

Advantage1
Lowest priced SMD buzzer on the market

Cost Comparison of Buzzers

In the case of other electronic component industry, many customers have switched from THT to SMD, as cost in using both was at the same level. However, it was not the case in the buzzer industry yet, so there had always been a high demand for more affordable SMD buzzers from customers.

This was one of those things that we have focused. We planned to make part with good performance and reliability, at the same cost comparing to THT type. To do this, we had to build our production process from bottom to top, to cut out labor cost which is quite expensive in Korea.

Though there still is price difference as seen in above chart, we expect that there will be no worries in switching from THT to SMD buzzer in the future considering the mounting cost, productivity, and failure ratio.

 

Advantage2 –
Patented simple structure which brings high reliability

An explanation of Structural difference against other makers’ buzzer

How does this difference bring reliability?

A. Simpler part, constant quality.
As shown in above comparison, Bosan part’s main body is uni-body made of magnet, while other parts in the industry is consisted with 2~3 subparts which requires bonding/welding.
This simple structure promises an important internal factor in generating sound to be in high volume. This also promises that there will be less internal deformation due to high temperature.

B. Less parts, less processes
Since smaller number of parts are required to build Bosan’s part, it is much easier to develop automated machines with high efficiency. Bosan has succeeded in developing those 10 years ago thanks to the simple structure, and the machines has got more accurate each year since then.

C. Un-manned coil winding
Unlike buzzers from other manufacturer in this industry, Bosan buzzer’s simple structure enables its coil to be directly wound and soldered inside of part with full auto machine. With well designed machine management system, all the coils are wound and soldered with machine accuracy so this part has less chance of getting defected after pick-n-place and reflow process.

 

Advantage3 – Swiftness and agility

Problem – what is happening in the industry

We receive inquiry from many customers all over the world complaining about former supplier’s irresponsible delivery. We see this problem arising from the culture of the Chinese industry, where most suppliers prefer doing manufacturing and distribution at the same time.
In other words, most of accidents happen because those suppliers forward product from its competitor.

We were in the same situation as well as those manufacturers years ago. Investing facilities/equipments for various kinds of product was not optimistic in most of cases. So we had to import from Chinese manufacturers and resell to customers.

Solution we have implemented

As time goes by however, we found out that it was essential to have a production system which can meet agility and reliability at the same time in the era of industrial booming. So we studied a production line which can produce from a hatchback to a sedan in one place, and the implementation was successful eventually.

As of 2017 this system is ready for SMD magnetic transducer, which is the major product of Bosanhitech. The first product from this system is BSMT-1140T series which we will introduce by this document and the Global Source trade show. And after collecting customer’s requirement through the show and all the communication, we plan to introduce 2 more product from 2018.

 

Product details
BSMT-1140T series

-. how to read part number

 Part number  BSMT-1140T-3024  BSMT-1140T-5024 BSMT-1140T-1420
dimension 11.0 x 11.0 x 4.0 mm
 rated voltage (Vo-p)  3.0  5.0 12.0
 operating voltage (Vo-p)  1.5 ~ 4.5 3 ~ 7  9.0 ~ 15.0
 rated frequency (Hz)  2,400 2,400  2,000
 DC resistance (Ω)  20±3 50±5  140±14
 min. SPL at 10 cm (dBA)  88 90  90
 lead material    Tin plated Brass
 housing material   LCP

 

th001-1

Introducing BSMT-1140T series,
The Most versatile SMD magnetic transducer in the industry.

From the establishment in 1997, our goal has always been making SMD magnetic transducers as a major product in the buzzer industry where THT type had been dominating.
After hearing customer all over the world’s feedback and getting through in-depth research, we finally developed new SMD magnetic transducer – BSMT-1140T series – with top versatility explained in this document.
Please find out why this part is different from others, and contact us or visit our booth.

 

Advantage1
Lowest priced SMD buzzer on the market

Cost Comparison of Buzzers

In the case of other electronic component industry, many customers have switched from THT to SMD, as cost in using both was at the same level. However, it was not the case in the buzzer industry yet, so there had always been a high demand for more affordable SMD buzzers from customers.

This was one of those things that we have focused. We planned to make part with good performance and reliability, at the same cost comparing to THT type. To do this, we had to build our production process from bottom to top, to cut out labor cost which is quite expensive in Korea.

Though there still is price difference as seen in above chart, we expect that there will be no worries in switching from THT to SMD buzzer in the future considering the mounting cost, productivity, and failure ratio.

 

Advantage2
Patented simple structure which brings high reliability

An explanation of Structural difference against other makers’ buzzer

How does this difference bring reliability?

A. Simpler part, constant quality.
As shown in above comparison, Bosan part’s main body is uni-body made of magnet, while other parts in the industry is consisted with 2~3 subparts which requires bonding/welding.
This simple structure promises an important internal factor in generating sound to be in high volume. This also promises that there will be less internal deformation due to high temperature.

B. Less parts, less processes
Since smaller number of parts are required to build Bosan’s part, it is much easier to develop automated machines with high efficiency. Bosan has succeeded in developing those 10 years ago thanks to the simple structure, and the machines has got more accurate each year since then.

C. Un-manned coil winding
Unlike buzzers from other manufacturer in this industry, Bosan buzzer’s simple structure enables its coil to be directly wound and soldered inside of part with full auto machine. With well designed machine management system, all the coils are wound and soldered with machine accuracy so this part has less chance of getting defected after pick-n-place and reflow process.

 

Advantage3
Swiftness and agility

Problem – what is happening in the industry

We receive inquiry from many customers all over the world complaining about former supplier’s irresponsible delivery. We see this problem arising from the culture of the Chinese industry, where most suppliers prefer doing manufacturing and distribution at the same time.
In other words, most of accidents happen because those suppliers forward product from its competitor.

We were in the same situation as well as those manufacturers years ago. Investing facilities/equipments for various kinds of product was not optimistic in most of cases. So we had to import from Chinese manufacturers and resell to customers.

Solution we have implemented

As time goes by however, we found out that it was essential to have a production system which can meet agility and reliability at the same time in the era of industrial booming. So we studied a production line which can produce from a hatchback to a sedan in one place, and the implementation was successful eventually.

As of 2017 this system is ready for SMD magnetic transducer, which is the major product of Bosanhitech. The first product from this system is BSMT-1140T series which we will introduce by this document and the Global Source trade show. And after collecting customer’s requirement through the show and all the communication, we plan to introduce 2 more product from 2018.

BST_5523SA_b