KE PIEZOCERAMIC BUZZERS

Transcription

1 KE PIEZOCERAMIC BUZZERS Contents Page Introduction...2 Makeup of piezoceramic buzzer products...2 Piezoceramic diaphragms...3 Piezoceramic ers...4 Piezoceramic buzzers(eb-type)...9 Piezoceramic buzzers(u-type)...15 How to use piezoceramic buzzers...17 Piezoceramic buzzer measurement method...18 Standard conditions for reliability tests...19 Caution...19

2 Introduction DK piezoceramic buzzers generate through the bending vibrations of a thin metal plate adhered to a piezoceramic disc. These buzzers feature a low power consumption, a safe, spark-free and non-contact structure, and a small size and light weight for an easy mounting to printed circuit boards. As a result, an increasing number of piezoceramic buzzers are now used to generate an artificial voice in combination with voice synthesizing ICs. To produce high-quality piezoceramic buzzers, DK has capitalized on many years of piezoceramics production and outstanding ceramic processing technologies and thin film forming techniques. By adding a sophisticated audio know-how to this manufacturing expertise, DK offers a large array of electronic tone generating products, such as piezoceramic diaphragms, ers and buzzers, to meet loud outputs, wide frequency ranges, and many other requirements. eatures Use of high-performance piezoceramic elements to meet loud volume and wide frequency range needs. High quality achieved by integrated in-house production, from piezoceramic materials to buzzers. Clear, pleasant electronic tone. Reliable, effective operation in a wide variety of equipment and ambient conditions. A wide, convenient selection from elements to complete buzzer products. Applications Consumer electronic appliances: Refrigerators, microwave ovens, washing machines, electric fans, VCRs, air conditioners, bath heaters, sewing machines Clocks and toys: Digital clocks and watches, alarm clocks, calculators, game machines, greeting cards Office equipment: Photocopiers, typewriters, cash registers, personal computers, facsimiles Automotive instruments: Speed alarms; reverse drive buzzers; light, oil, battery, seatbelt check ers Safety and security equipment: ire alarms, burglar alarms, gas leakage alarms, keyless entry Other electronic equipment: Vending machines, automatic controllers, bicycle horns, telephones, cameras, strobos Makeup of piezoceramic buzzer products Piezoceramic diaphragms External-drive (EE-type) Self-drive (E-type) q w q e e r w r q Electrode (silver) w Ceramic disc e Adhesive r Metal plate (brass,stainless steel) Piezoceramic buzzer products Piezoceramic ers External-drive (EE-type) Self-drive (E-,OS-types) Casing Piezoceramic diaphragm Lead wire Casing Pot-type piezoceramic diaphragm Circuit board Piezoceramic buzzers (EB-,U-types) Lead wire to power source Casing Piezoceramic diaphragm Lead pin to power source Please refer to page 17 for the difference between external-drive type and self-drive type. 2

3 Piezoceramic diaphragms How piezoceramic diaphragms are named w p Å y e Å q w e r t qee: External-drive type E: Self-drive type wouter diameter of metal plate in mm eshape code rresonant frequency in.1 khz tterminal code External-drive type diaphragm rating Parts number Electrical characteristics Dimensions (mm) Metal plate Weight Resonant Resonant Max. input Rated working Metal plate Total Metal plate Shape frequency resistance Capacitance Piezoceramic element voltage temperature range outer diameter thickness thickness material (g) (p) outer diameter (khz) (Ω max.) (Vp-p max.) ( C) (φd) (φd) (T) (t) EE13A-A 7.±.5 4,±3% 3 2 to A Brass.2 EE2A-63A 6.3±.6 3,±3% 3 2 to A Brass.8 EE27A-39A 3.9±.5 2 2,±3% 3 2 to A Brass 1.6 EE35A-3A 3.± ,±3% 3 2 to A Brass 3.4 Self-drive type diaphragm rating Parts number Electrical characteristics Dimensions (mm) Metal plate Weight Resonant Resonant Max. input Rated working Metal plate Piezoceramic Total Metal plate Shape element frequency resistance Capacitance voltage temperature range outer diameter material (g) outer diameter thickness thickness (p) (khz) (Ω max.) (Vp-p max.) ( C) (φd) (φd) (T) (t) E27A-41A 4.1± ,±3% 3 2 to B Brass 1.6 E35A-3A 3.±.5 2 3,±3% 3 2 to B Brass 3.4 Shapes A External-drive type B Self-drive type φd φd t T φd φd t T 3

4 Piezoceramic ers How ers are named [EE- and E-types] wr KK apple eu Ï qqp e q w e r t y u i [OS-type] ØÍÏ y Í wq Î q w e r qee: External-drive type E: Self-drive type wouter diameter of casing in mm eheight: Approx. height in mm when mounted rshape code toscillating frequency in.1 khz yterminal code ulead wire length: Length in mm from external surface of casing (omitted when lead pins) irated input voltage: Voltage for measuring of output pressure;for operating voltage, refer to max. input voltage. qpiezoceramic er: General name for OS-type ers wshape code edimensions: Outer diameter of diaphragm in mm rseries code External-drive type er rating (Measurement condition: 25 C±2 C, 45~6% RH) Electrical characteristics Shapes and structures Parts Output pressure Max input Rated working Dimensions (mm) Weight number (db min.) Capacitance voltage temperature range Shape Terminal Casing Outer (Measurement condition) (p) (Vp-p max.) ( C) Height color (g) diameter EE143K-39YB6-5V kHz square wave 19,±3% 5Vp-p, cm (1kHz) 25 2 to +6 φ B Lead wire Black.5 EE17K-4R-3V 73 4,96Hz square wave 19,±3% 3Vp-p, cm (1kHz) 3 2 to + φ17 8 C Lead pin Black 1.3 EE28K-4R-3V 75 4,96Hz square wave 14,±3% 3Vp-p, cm (1kHz) 3 2 to + φ D Lead pin Black 2.2 EE29K-25R-12V kHz square wave 2,±3% φ to + 12Vp-p, cm (1kHz) (24.5) 9 E Lead pin Black 2.4 EE2115K-28R-12V kHz square wave 2,±3% φ to Vp-p, cm (1kHz) (24.5) 9 Lead pin Black 2.2 EE24K-371-3V 75 4,96Hz square wave,±3% 3Vp-p, cm (1kHz) 3 2 to +6 φ G Lead wire Black 2.3 EE3K-35-3V kHz square wave 2,±3% 3Vp-p, cm (1kHz) 3 to +6 φ3 5.5 H Lead wire Black 4. EE3314K-R-12V 75 1kHz square wave 56,±3% 12Vp-p, cm (12Hz) 3 2 to + φ I Lead pin Black 5.2 EE332K-R-12V 75 1kHz square wave 56,±3% 12Vp-p, cm (12Hz) 3 2 to + φ J Lead pin Black 5.3 EE346K-R-6V 1kHz square wave 38,±3% 3Vp-p, 1m (12Hz) 6 2 to + φ K Lead pin Black 3.3 Although rated power supply voltage is shown at the end of parts number, refer to the column of maximum input voltage for operation securing voltage. External-drive type er shapes B EE143K-39YB6-5V φ

5 External-drive type er shapes C EE17K-4R-3V φ3.5 D EE28K-4R-3V Unit=mm 2-φ3.5 φ17 φ φ φ Lead pin close-up Lead pin close-up E EE29K-25R-12V A EE2115K-28R-12V A 6± ± ± Close-up of A Close-up of A.2.6 G EE24K-371-3V H EE3K-35-3V 1± ±5 2-φ ±2 5±2 φ φ3 35±.1 41 φ2.2 Recommended sclew fixing torque M2 round headed small screw: 2. kg fcm max. I EE3314K-R-12V Close-up of A Recommended sclew fixing torque M2 round headed small screw: 2. kg fcm max. J EE332K-R-12V 14 6± A Close-up of A φ ±.5 A φ ± K EE346K-R-6V 6.3 A Close-up of A 3.4 φ

6 External-drive type ers: pressure vs. frequency EE143K-39YB6-5V requency (khz) EE29K-25R-12V requency (khz) EE3K-35-3V requency (khz) EE17K-4R-3V requency (khz) EE2115K-28R-12V requency (khz) EE3314K-R-12V 9 6 EE28K-4R-3V requency (khz) EE24K-371-3V requency (khz) requency (khz) EE332K-R-12V requency (khz) EE346K-R-6V requency (khz) Example of recommended external-drive type er circuit Input: square wave, rated voltage (3 Vpp for EE346K-R-6V) distance: cm (1 m for EE346K-R-6V ) DC+ If R2 & C becomes high oscillateing frequency becomes low, and if R2 & C becomes low oscillating frequency becomes hight. By changing of R2 & C,oscillating frequency changes..22µ R1 2k R2 25k R3 2k DC+ R2 k C 1n.47µ Tr1 C1 R4 15k Tr drive R5 15k C2.47µ Tr2 Tr1 & Tr2 is equivalent to 2SC18158L. Piezoceramic ers R1 12k C-MOS IC is equivalent to MC1411 IC drive Piezoceramic ers C1 R1 Ringer IC Ringer IC drive R2 C2 6

7 Self-drive type er rating Parts number (Measurement condition: 25 C±2 C, 45~6% RH) Electrical characteristics Shapes and structures Weight Oscillation Output pressure Current Rated power Operating Rated working Dimensions (mm) (db min.) Oscillating Consumption supply voltage voltage temperature range Shape Terminal Casing (khz) Outer (g) (Measurement condition) (ma max.) (VDC) (VDC) ( C) Height color diameter E3114K-3S-12V Continuous 75 (12VDC, 1m) 3.± to18 2 to +6 φ A Lead pin Black 5.1 OS-27B Continuous 77 (12VDC, 1m) 3.3± to2 2 to + φ B Lead pin Ivory 3.3 OS2-27B Continuous 77 (12VDC, 1m) 3.3± to2 2 to + φ C Lead pin Ivory 3.3 OS3-27B Continuous 75 (12DVC, 1m) 2.9± to18 2 to + φ C Lead pin Ivory 3.5 OS4-27B Continuous 75 (12VDC, 1m) 2.9± to18 2 to + φ B Lead pin Ivory 3.6 OS5-32B Continuous 9 (24VDC, 1m) 2.5± to33 2 to + φ B Lead pin Black 5 OS6-21D Continuous (12DVC, 1m) 3.7± to18 2 to + φ B Lead pin Gray 1.7 OS6S-21D Continuous 73 (12VDC, 1m) 3.6± to18 2 to + φ D Lead pin Gray 1.8 Above data were obtained by measurement using DK s test circuits. Please refer to each product specification about circuit and components. Self-drive type er shapes Unit=mm A E3114K-3S-12V B OS-27B, OS4-27B, OS5-32B, OS6-21D Main terminal sign M Ground Polarity sign R17 φ φ3 12 G φa 2 A G Soldering G 3-φ1±.2 B C 4 Close-up of A.2.6 M: Main terminal : eedback terminal G: Ground φe M M:Main terminal :eedback terminal G:Ground 12 Recommended hole positions on printed circuit board Parts number φa B C φe G OS-27B OS4-27B OS5-32B OS6-21D The OS6-21D case has the same shape as that of OS6S-21D 7

8 Unit=mm C OS2-27B, OS3-27B φa G 3-φ1±.2 φe M B C 4 M: Main terminal : eedback terminal 12 G: Ground Recommended hole positions on printed circuit board Dimensions φa B C φe G OS2-27B OS3-27B Parts No. G D OS6S-21D 2.5 G 3-φ.9±.1 φ ±.3 6 M: Main terminal : eedback terminal G: Ground 6 (12) 21 4 Self-drive type ers: pressure vs. input voltage M M: Main terminal : eedback terminal G: Ground 12 Recommended hole positions on printed circuit board 9 3 E3114K-3S-12V Current consumption distance: 1m E3114K-3S-12V 4 2 Current consumption distance: 1m 9 OS-27B OS2-27B 3 OS3-27B OS4-27B distance: 1m OS5-32B 3 Current consumption OS6-21D OS6S-21D Example of recommended self-drive type er circuit R2 R3 Tr1 R1 M G R2 R3 G M Tr R1 R4 R5 C R7 Tr3 R6 Tr2 D R2 R3 R1 Tr1 Intermittence period Setting of Tsec. R5=R6 T=1.4 C (R4+R5) (Sec.) G M Continuous (1) Continuous (2) Intermittent 8

9 Piezoceramic buzzers (EB-type) How buzzers are named [EB-type] ı eq pt Å ep Ç Ç qrp qw q w e r t y u i o qpiezoceramic buzzer: General name for EB-type buzzers wouter dimensions: Approx. outer diameter of casing in mm eheight: Approx. height in mm when mounted rshape code toscillating frequency in.1 khz EB-type buzzer rating Parts number yoscillation : C(continuous ), I (intermittent ) uspecial specification K: washable ilead wire length: Length in mm from external surface of casing (omitted when lead pins) orated power supply voltage Voltage for measuring of pressure etc.; for operation securing voltage, refer to operating voltage column. (Measurement condition: 25 C±2 C, 45~6% RH) Electrical characteristics Shapes and structures Oscillation Oscillating Current Rated power Operating Rated working Dimensions (mm) Casing (db min.) frequency consumption supply voltage voltage temperature range Shape Terminal Sound Outer (Distance:m) (khz) (ma max.) (DC.V) (DC.V) ( C) Height color diameter EB2A-35CW14-12V Continuous (.3) 3.5± to2 to+6 φ A Lead wire Black 4.2 EB2E-35C-12V Continuous (.3) 3.5± to2 2to+6 φ23 12 B Lead pin Black 3.1 EB2Z-32C-9V Continuous (.3) 3.2± to12 to+ φ C Lead pin Black 4.4 EB22A-38C-12V Continuous 75(.3) 3.8± to24 to+6 φ D Lead pin Black 2.5 EB23A-3C-12V Continuous 75(.3) 3.± to32 2to+6 φ E Lead pin Black 3.2 EB23B-3C14-12V Continuous 75(.3) 3.± to32 4to+6 φ Lead wire Black 3. EB255A-31C-12V Continuous (.3) 3.1± to2 2to+ φ25 5 G Lead pin Black 1.9 Weight (g) EB255A-31CK-12V Continuous (.3) 3.1± to2 2to+ φ25 5 H Lead pin Black 2. EB259A-27C-12V Continuous (.3) 2.7± to2 2to+ φ I Lead pin Black 3.2 EB2617A-25C-12V Continuous (.3) 2.6± to28 3 to + φ J connection Black 5.2 terminal EB3B-31C-9V Continuous (1.) 3.1± to32 2to+6 φ K Lead pin Black 7.4 EB3D-31C15-9V Continuous (1.) 3.1± to32 2to+6 φ L Lead wire Black 8.3 EB35A-3C14-12V Continuous (.3) 3.± to15 2to+6 φ31 5 M Lead wire Black 3.9 EB35A-3C-12V Continuous (.3) 3.± to15 2to+6 φ31 5 N Lead pin Black 4.9 EB312A-35C15-12V Continuous 9(1.) 3.5± to2 2to+ φ L Lead wire Blue 9.5 EB415A-3C15-9V Continuous (1.) 3.± to12 2to+6 φ O Lead wire Black 13.1 EB415A-3C-9V Continuous (1.) 3.± to12 2to+6 φ P Lead pin Black 13. EB415B-28C15-24V Continuous 85(1.) 2.8± to28 2to+6 φ O Lead wire Black 13.7 EB415B-28C-24V Continuous 85(1.) 2.8± to28 2to+6 φ P Lead pin Black 13.7 EB415B-28 I 15-24V Intermittent 85(1.) 2.8± to28 2to+6 φ O Lead wire Black 13.7 EB415C-3C15-24V Continuous 9(1.) 3.± to28 2to+6 φ O Lead wire Black 13.7 EB5838A-27C1-12V Continuous 92(1.) 2.7± to16 3to+ φ58 37 Q Lead wire Black 62. The condition where the anti-liquid seal on the hole is removed. requency of intermittent : ±5msec. As EB2617A-25C-12V has electric connection terminal in the bottom of the fixing hole, fixing of buzzer and electric connecting can be done at the same time. 9

10 EB-type buzzer shapes A EB2A-35CW14-12V B EB2E-35C-12V Unit=mm 14±5 ± φ ± φ Close-up of lead pin Recommended screw fixing torque M2 round headed small screw:.5kgfcm max. Lead wire Red(+),White(-) C EB2Z-32C-9V D EB22A-38C-12V ±.3 4.6±.5 1.± φ Close-up of lead pin φ22.6±.5 Polarity sign 15.±.5 φ1.max. E EB23A-3C-12V EB23B-3C14-12V ± φ ± ±.5 ±2 φ ± φ2.3 φ1.5max. φ2.3 Recommended screw fixing torque M2 round headed small screw:.5kgfcm max. Lead wire Red(+),Black(-)

11 Unit=mm G EB255A-31C-12V H EB255A-31CK-12V coating agent I EB259A-27C-12V J EB2617A-25C-12V φ φ ±.5 φ φ1.5max K EB3B-31C-9V L EB3D-31C15-9V or EB312A-35C15-12V ±2 15± φ ± ±.5 φ ±.3 45 φ25 15.±.1 φ25 15.±.1 φ1.2 Close-up of lead pin.4.8 Polarity sign.3.2 Anti-liquid seal 3.8 φ1.2 Polarity sign Close-up of lead pin φ1.5max. φ3.4 φ3.4 Recommended screw fixing torque M3 round headed small screw: 3.kgfcm max. Lead wire Red(+),Black(-) 11

12 M EB35A-3C14-12V N EB35A-3C-12V 5 φ φ4.5 14±5 ±3 φ31 φ34.5± φ φ2. Close-up of lead pin Recommended screw fixing torque M2 round headed small screw:.5kgfcm max. Lead wire Red(+),Black(-) O EB415A or EB415B or EB415C P EB415A or EB415B 15.5 φ φ3.5 φ1.5max. φ φ ±2 15± Recommended screw fixing torque M3 round headed small screw: 3.kgfcm max. Lead wire Red(+),Black(-) Slot indicates+pole Q EB5838A-27C1-12V φ φ Recommended screw fixing torque M4 round headed small screw: 3.kgfcm max. Lead wire Red(+),Black(-) 12

13 EB-type buzzers: pressure vs. input voltage 9 distance:.3 m 3 qeb2a-35c14-12v web2e-35c-12v eeb2z-32c-9v e e Currebt consummption qw 4 2 reb22a-38c-12v yeb23b-3c14-12v teb23a-3c-12v ueb259a-27c-12v ieb255a-31c-12v, EB255A-31CK-12V 4 Current ty consumption distance:.3m 9 3 r u i u i r ty 2 qw oeb2617a-25c-12v!eb3b-31c-9v!1eb3d-31c15-9v!2eb35a-3c14-12v!3eb35a-3c-12v!4eb312a-35c15-12v!5 EB415A!6 EB415B!77EB415C!8 EB5838A Current consumption!2!3!2!3!4!4 9 3!!1 o o Current!8 consumption!8 distance: 1m 3!7 9!5!5!6Continuous!6Intermittent!7 2!6Continuous!6Intermittent distance: 1m

14 EB255A-31CK-12V washable type Washing method Buzzers of this model is wet-washable. or washing by other methods, please consult our engineers. Resistance to solvents EB255A-31CK-12V buzzers have the following solvent-resistance characteristics. If you are planning to use solvents other than those listed below, please consult our engineers. Solvent-resistance test conditions Dipped in solder pot (at 245±5 C for 8 sec.) d Immersed in solvent (for 3 minutes) d Dried (at 6 C for 3 minutes) d Standard reliability test (refer to P.19) Test results Solvent Result Pure water Isopropyl alcohol (IPA) Toluene Isopropyl alcohol + toluene (1:1) K K K K Chlorosen K Methanol Methylenechloride K : Satisfactory Trichloroethylene : Unsatisfactory After washing, remove the anti-liquid seal before reuse. 14

15 Piezoceramic buzzers (U-type) Information on product naming [U-type] Ë w t p  Î1 Î2 Ó q w q w e r t y q Generic symbol for U-type piezoceramic buzzers r Oscillation s: R (continuous s), D1 (short w Shape number intermittent s), D2 (long intermittent s) e Dimensions: Outer diameter of diaphragm (mm) t Symbol indicating the presence of a horn y Rated power supply voltage:voltage for measuring of pressure etc.; for operation securing voltage, refer to operating voltage column. U-type buzzer rating (Measurement condition: 25 C±2 C, 45~6% RH) Electrical characteristics Shapes and structures Parts Oscillating Current Rated Operating Rated working Dimensions (mm) Weight Oscillation consumption power temperature Casing number (db min.) frequency supply voltage Shape Terminal (g) Outer voltage range Height color (Distance:m) (khz) (ma max) (DC.V) (DC.V) ( C) diameter Continuous + U1-5RD112V (1.) 2.7± to18 2 to Q Lead wire White 39 short intermittent Continuous + U1-5RD124V 75(1.) 2.7± to33 2 to Q Lead wire White 38 short intermittent U1 Continuous + U1-5RD212V (1.) 2.7± to18 2 to Q Lead wire White 39 long intermittent Continuous + U1-5RD224V 75(1.) 2.7± to33 2 to Q Lead wire White 39 long intermittent Continuous Soldered U2-5RD1D212V + short intermittent 75(1.) 2.7± to18 2 to + 6 φ6 33 R Black + long intermittent terminal U2 Continuous Soldered U2-5RD1D224V + short intermittent (1.) 2.7± to33 2 to + 6 φ6 33 R Black + long intermittent terminal Continuous U2-5RD1D2H12V + short intermittent (1.) 2.7± to18 2 to + 6 φ9 36 S Lead wire Gray 15 + long intermittent U2H Continuous U2-5RD1D2H24V + short intermittent 85(1.) 2.7± to33 2 to + 6 φ9 36 S Lead wire Gray 15 + long intermittent Soldered U4 U4B-21RM-1 Continuous 72(1.) 2.85± to15 2 to + φ23 18 T Black 4 terminal U8-35R9V Continuous (1.) 3.3± to12 2 to + 6 φ4 23 U Lead wire Black 15 U8 U8-35R24V Continuous (1.) 3.3± to33 2 to + 6 φ4 23 U Lead wire Black 15 Abbre.name Intermitting period: Hz±3% (short intermittent) 2 Hz±3% (long intermittent) Heat resistance of U2 will be up to +85 C U-type buzzer shapes Abbre. name Shape Input voltage characteristics Unit = mm U1 Q 4 4-φ Current consumption q 12V w 24V q qintermittent distance: 1m w wintermittent Recommended screw fixing torque M4 round headed small screw: 3kgfcm max. R + D1 135 Black Red Black (-,continuous)(+)(-,intermittent) wcontinuous qcontinuous

16 Abbre. name Shape Input voltage characteristics Unit = mm U2 R 39.5 φ No.1(-,long intermittent) No.2(-,short intermittent) No.3(-,continuous) φ6 φ56 Recommended screw fixing torque M3 round headed small screw: 3.kgfcm max holes Current consumption q 12V w 24V q qintermittent distance: 1m w wintermittent wcontinuous qcontinuous 2 3 U2H S φ9 φ6 φ holes 1 9 Current consumption q 12V w 24V q qintermittent distance: 1m w wintermittent Recommended screw fixing torque M5 round headed small screw: 3.kgfcm max. Black (-,continuous) White (-,short intermittent) Red (+) Green (-,long intermittent) wcontinuous qcontinuous 2 3 T Current consumption U4 φ23± φ.8 15±.3 9 (db/1m) U Current consumption q 9V w 24V distance: 1m 4 U8 φ24 φ q q w w 3 2 Recommended screw fixing torque M3 round headed small screw: 3.kgfcm max. Red Black (+) ( - )

17 How to use piezoceramic buzzers Piezoceramic diaphragms have a simple structure consisting of a piezoceramic disc (piezoceramic element) adhered to a thin metal (or plastic) plate. When a voltage is charged in the polarization direction, the piezoceramic element contracts, and expands when voltage is charged in the reverse direction. The quick contractionexpansion motions of the piezoceramic element cause the elastic disk underneath to vibrate and generate waves. (See ig 1) How the piezoceramic diaphragm generates The piezoceramic diaphragm generates by either the externaldrive or the self-drive oscillation technique. External-drive ig. 2 (a) t Oscillation mode Oscillating frequency Operation at any frequency eatures Easy generation of by nonstable multivibrator circuit (see recommended circuit example on page 4). Direction of polarization (a) External drive (b) Self drive ig. 1: Distortion of diaphragm External-drive circuit Power supply + + Self-drive ig. 2 (b) Resonance at frequency corresponding to minimum acoustic impedance of diaphragm Derives loud output through positive feedback oscillation circuit (see recommended circuit example on page 6). How piezoceramic diaphragms are supported Piezoceramic diaphragms are placed in casings equipped with a resonator, to obtain a required output. These diaphragms are supported inside the casings by either the nodal-circular support or peripheral support technique, and should be attached to the support by an elastic adhesive such as a silicone agent. Supporting method Nodal-circular support ig. 3 (a) Peripheral support ig. 3 (b) eatures Allows a virtually free and unrestricted vibration, and thus closely reproduces the acoustic impedance characteristics of the diaphragm. Provides a greater strength against mechanical stress and more stable performance. Particularly suitable for a loud volume generation. Used to lower the resonance frequency of the piezoceramic diaphragm by suppressing the peripheral vibrations. May not have enough strength to resist the mechanical stress at the support area. Design of the resonator The piezoceramic diaphragm cannot produce a loud volume only by a nodal-circular or peripheral support, and it is necessary to tune the diaphragm to the air acoustic impedance, a job done by the resonator (see igure 4, cavity v). The resonator is designed according to the equation below. fcav= c 2π πa 2 (16a/3π+t)d 2 πh fcav: Resonance frequency of cavity (Hz) c: Speed of (331+.6t) 3 ( mm / sec) a: Radius of hole (mm) (Hz) d: Radius of supporting ring (mm) h: Height of cavity (mm) t: Thickness of hole (mm) 9 9 Input: Square wave 3Vp-p distance: cm requency (khz) Input: Square wave 3Vp-p distance: cm Self-drive circuit ig. 2: Method of generation (a) Nodal-circular support requency (khz) (b) Peripheral support ig. 3: Supporting method 2d 2a V Power supply h ig. 4: Resonator for piezoceramic diaphragm 17

18 Booster coil When the generated is less audible due to muffling by the casing, a booster coil is used to amplify the (see the righthand figure for an example of a circuit with a booster coil). Given the rise time and breaking time, t sec., of the switching of the transistor by a voltage output from an LSI or other components, a counter voltage is generated in proportion to the coil inductance L and 1/t. Since this counter voltage has a Vp-p several times greater than the power supply voltage, a proportionally greater pressure is obtained. In some cases, a capacitor and a diode are included in the circuit to absorb surge current and thus protect the transistor. Example of circuit Diode L Tr Capacitor Buzzer Piezoceramic buzzer measurement method Standard measurement conditions Temperature: 25±2 C Humidity: 45 6% RH Electrical characteristics 1) Resonant frequency and resonant resistance Measured by an impedance analyzer 2) Capacitance Measured by a universal bridge or LCR meter (measured between poles at 1 khz) Acoustic characteristics of piezoceramic ers and buzzers The oscillating frequency, current consumption and pressure are measured by the measuring instruments shown below. distance (a) External-drive type er (b) Self-drive type er Oscillator Wave shaping circuit Sounder DC power supply Oscillating circuit Sounder Microphone Microphone Noise meter Noise meter (c) Buzzer DC power supply Ampere meter Buzzer Microphone Noise meter ig. 1: formats for acoustic characteristics In the measuring test, ers and buzzers are placed as follows: distance Microphone Sounder or buzzer Jig Anechoic room ig. 2: Sounder and buzzer placement for measurement distance KPiezoceramic er (self vibration and separate vibration types) After measuring the pressure level from cm away, the measured value is converted according to the rated distance of each er model. KPiezoceramic buzzer After measuring the pressure level from 5 cm or cm away, the measured value is converted according to the rated distance of each buzzer model. 18

19 Conversion of pressure by distance The pressure values shown in this catalog are not directly comparable because of different measuring distances. Therefore, the following conversion equation should be used for any comparison. B = A + 2 log (La/Lb) A: value at measuring distance of La B: value at measuring distance of Lb The relationship between an increase in measuring distance and a lowering of pressure can be estimated by consulting the table below. Distance increase 2 times 3 times 4 times 5 times 6 times 7 times 8 times 9 times times drop (db) Standard conditions for reliability tests High-temperature placement The product is subjected to its upper limit operation temperature (t2) for 5 hours. Low-temperature placement The product is subjected to its lower limit operation temperature (t1) for 5 hours. High-temperature and high-humidity placement The product is placed in a 6 C, 9 95% RH condition for 5 hours, during which the ON-O operation is checked every 3 minutes. Temperature cycle One cycle consists of one hour of the t1 routine and one hour of the t2 routine, and a total of 24 cycles are imposed. attenuation (db) distance(cm) ig. 3: Distance- presssure conversion chart Vibration The product is shaken for two hours in the same direction for a total of six hours in three directions, at a frequency of -55- Hz, an amplitude of 1.5 mm, and a sweep time of one minute. Shock The product is dropped three times continuously in the same direction under a gravitational force of G, for a total of nine drops in three directions. After the completion of each test, the product is left under room temperature for 24 hours, and then undergoes standard tests; the measured values, i.e., the value of oscillating frequency, current consumption, or pressure, should not deviate by more than ±% from the initial measurement values. Caution 1. When mounting and handling (1) To prevent malfunctions, install the piezoceramic buzzer or er so that it does not come into contact with other componets on its side or top surface. (2) Do not block the opening of the buzzer or er. Maintain a distance of at least mm between the opening and any surrounding object. Also, do not cover the opening with an adhesive tape or the like. If the hole is blocked, the buzzer or er may exhibit abnormal oscillation or stop functioning. (3) The pressure of the buzzer or er may be measured after, but not before, it is installed in the host equipment. When determining the installation position, make sure that adverse acoustic impedance does not exist in the installation area. If acoustic impedance exists, the buzzer or er may exhibit abnormal oscillation or stop functioning. (4) When securing the buzzer or er with screws, tighten the screws within the specified torque range. Use pan-headed screws and washers so the buzzer or souder casing will not be deformed. A deformed casing may cause the buzzer or the er to exhibit abnormal oscillation or stop functioning. (5) When stripping a lead wire, do not cut the conductive line inside the coating, thereby ensuring the will be properly generated. Use a stripper suitable for the diameter of the lead wire. (6) Do not apply strong force to the pins before they are soldered. If the pins are bent or cut due to excessive force, the buzzer or er may not generate. (7) Do not use the wrong polarity. If the buzzer or er is improperly connected, the internal circuit may break down when electricity is applied. (8)Use the buzzer or er within the operation voltage range. A higher voltage may damage the diaphragm and other componets or cause a fire. With a lower voltage, the may not be produced. (9) Do not apply a DC current to the piezoceramic er. Otherwise, silver migration may occur, which will lower the insulation resistance and cause the er to stop functioning. 19

20 () Use a low-impedance (not more than Ω) power supply for the buzzer; otherwise, the buzzer may exhibit abnormal oscillation or stop functioning. (11) Do not interpose a resistance in series between the buzzer and the power supply, else the buzzer may exhibit abnormal oscillation or stop functioning. If the interposition of a resistance is necessary to adjust the volume, insert a capacitor of approximately 1 µ in parallel, not in series, as shown in igure 1. (12) Do not use the buzzer or er in a corrosive ambience, such as an ambience containing sulfur hydrides. Otherwise, a normal may not be generated due to corrosion of the componetnts and diaphragm. (13) When washing, be sure that a solvent or the vapor of a solvent does not infiltrate the buzzer or the er, thereby preventing deterioration and damage by the solvent trapped inside the casing. (14) Do not drop the buzzer or er. When subjected to a mechanical shock, the er may accumulate a high voltage inside its piezoelectric elements, resulting in an electric shock to anyone who touches it. Also if such a er is connected to a circuit, it may damage transistors and/or other electronic components. Sounders which may have accidentally been subjected to a mechanical shock can be made safe by shorting them between the poles. Then check the pressure, tone and appearance before use. (15) Take special protective measures to prevent deterioration and breakdowns, whenever the buzzers or ers are stored in the following unfriendly areas: q Dusty places r Moist places w Hot or frosty places t Humid places e Areas exposed to sunlight y Areas exposed to solvents or their vapor (16) When operating the buzzer or er outdoors, protect it from moisture to ensure normal operation. (17) When soldering on diaphragms, use a solder containing 2% silver and finish each sodering job within 1 second at a soldering temperature of 3± C. If the solder does not contain silver, diaphragm performance may be adversely affected. When soldering buzzers and ers having lead pins, complete each soldering job manually within 3 seconds at a sodering temperature of 3 32 C Moreover, in the case of the EE17K, EE28K, EB255A and EB35A models, manually complete each soldering job within 5 seconds at 26±5 C. (18) To protect an LSI from a counter voltage of the er, which may be caused by an external mechanical shock, connect a Zener diode or varister in parallel to the LSI, as shown in igure 2. VDD Piezoceramic buzzer ig. 1 3KΩ max. 1µ LSI ig. 2 Piezoceramic buzzer 2. When storing To prevent deterioration and/or breakdowns, do not store buzzers and ers in the following places: q Dusty places t Humid places w Hot or frosty places y Areas exposed to solvents or their vapor e Areas exposed to sunlight u Areas exposed to corrosive gases, such as H2S r Places with leaking or infiltrating water 3. Other precautions q To maintain the initial performance and safety standard of the buzzer or er, do not disassemble, repair or modify it. w The products contain the lead so that the disposal of industrial wastes has to be required. 2

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