N Name 1 Housing 2 Coil 3 Magnet 4 Pin 5 Winding 6 Weight 7 Resonance 8 P. C. 9 Epoxy 10 Components 11 Silicon Rubber 12 Enamelled wire

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1 Our line of miniature magnetic transducers offer the highest quality and reliability at a cost effective price. Our extensive line of transducers include devices that are sealed for wave and wash processes, have side sound ports, and include a variety of different sizes to help meet all your design parameters. N Housing Coil Magnet Pin 5 Winding 6 Weight 7 Resonance 8 P. C. 9 Epoxy Components Silicon Rubber Enamelled wire Printer, telephone, timer, pager, cellular phone, electronic oven, electronic cash register, POS system, electronic typewriter, computer terminals, keyboard, copy machine, safety equipment for motor vehicles, portable and battery operated equipment. *Note: All the transducers in this catalog require external circuitry to provide the drive signal to the transducer. If the voltage signal input Vo-p is applied to our transducer with the polarity reversed, a sound will be generated but it will not always meet the catalog specifications for the sound pressure level. This is because the reversed polarity input changes the magnetic force direction from "attract" to "repulse" or vice versa, which can cause the resonant frequency to deviate from its original point and produce variations in the sound pressure level. However, if the voltage signal input alternates from positive peak to negative peak (Vp-p), the reversed polarity will have no effect on the sound produced. A / cm V Some Design engineers do not drive audio transducers at eh rated voltage recommended by the manufacturer. In most cases this is due to the voltage available relative to the customer's specific application. Our catalogues and data sheets shows the frequency characteristices with respect to the rated voltage. When different amplitudes are applied to a given transducer, the frequency characteristices change. Generally, as the input voltage amplitude decreases below the rated voltage, the resonant frequency (fo) rises. Conversely as the input voltage increases above the rated voltage, the resonant frequency (fo) falls. The basic resonant frequency of a specific transducer is a fixed value relative to its acoustic design. As a result, at lower than rated voltage the frequency response band tends to narrow, and at higher voltage values the frequency band tends to be wider. Consequently if the input voltage is too low, shifting the resonant frequency higher, the original rated frequency (i.e.,8) may not fall within the frequency band. Thus the sound output will be well below the rated SPL. V 6V 5 K K K K 5K (ma) V 6V V 5 K K K K 5K Type RDX-6 applied voltage: V, 6V, V, / duty, square wave Distance for measurement:cm The sound producing devices like our sound transducers are generally used in certain enclourse to have an appropriate resonance chamber in front of the sound producing device, it is possible to meet the requirements to a certain extent, for instance, to obtain an increased sound pressure, improved response in wider range of frequencies, or softened sound output. Design such resonator called Helmholtz Resonator" according to the following equation: fv: V: D: Resonant frequency of resonator Volume of resonance chamber Diameter of sound emission hole [] [mm ] [mm] ØD V L L: Depth of sound emission hole [mm] C: Speed of sound = approx. [mm/sec]

2 Designing the resonator to have such dimensions that the resonant frequency (fv) of the resonance chamber may be greater than the resonant frequency (fo) of the sound producing device, improves the frequency response in wider frequency range, increases the sound pressure and softens the sound output eliminating harmonic components. (These effects may not be obtained if fv is lower than fo, or reduced if fv is excessively higher than fo. For increasing the sound pressre only, it is recommended to set the fv two times as high as fo.) [Design] To broaden the frequency range to 8~, the resonator geometry is determined with an aim that the fv should be around, slightly higher than the fundamental frequency of the transducer. The sound hole diameter ød is set to.5mm. With those parameter set, the fv may be calculated as 6 form the equation (I). [Actual Measurement] Frequency Response...as shown in Fig. fv... As shown in Fig., the frequency range may be broadened and a softer sound may be produced with the harmonic components considerably eliminated. [Design] To increase the SPL at the findamental frequency of 8, the resonator geometryis determined with an aim that the fv should be around, almost twice as high as the fundamental frequency of the transducer. The sound hole dimeter ød is et to.mm. With those parameters set, the fv may be calculated as from the equation (I). [Actual Measurement] Frequency Response...as shown in Fig. fv... As shown in Fig., the SPL range may be considerably increased, while the sound may become sharper due to its secondary harmonic components increased K K 5K K Fig. Frequency response without additional resonator 5 K K 5K K Fig. Frequency response with resonator (Design I) 5 K K 5K K Fig. Frequency response with resonator (Design II) Our standard circuit for measurement is as shown below: The term "Rated Voltage" in the specifiacation of DB's Transducers are described as: -For Miniture Audio Transducers (External Drive Circuitry) VPEAK V e.g. MDXC: Rated Voltage is ".5V".5V=.5Vo-p

3 Mearsuring Method for Magnetic Transducer ±s ±5 C 5 C Max C 5± C ±s ±s Reference standard: EIAJ ED- Infrared reflow oven If you have any questions about the above temperature profile for infrared reflow oven, please feel feel to contact us. Our electronic buzzer is a compact device capable o producing high sound pressure levels with minimum power consumption. This is achieved by the use of a self-contained, feedback controlled, transistorized oscillator circuit, housed completely within the device. All models are low frequency devices ( ~ 5HZ) which utilize an oscillating hammer to resonate a membrance. The Hammer is controlled by an electromagnetic assembly (Fig.). Fig. shows a typical circuit diagram utilized within each buzzer; the frequency of the oscillator circuit is approximately,hz, while the natural frequency of the hammer is HZ. When the current flows through the coil, L and the hammer begin to vibrate, another coil, L detects its vibration, providing feedback to a transistor so that the oscillator becomes synchronized with the vibrating hammer. No + Housing Mylar Diaphragm R L 8 Magnet Patter 9 P.C. Board Tr Coil Base L D 6 7 Fig. Cut-away view of Type SMB Lead Wire Magnet Bobbin GND D Fig. Circuit diagram of Type DB-E8 The miniature electro-magnetic transducer should not be exposed to extremely high temperature for prolonged period of time. As excessive heat will degrade the sealing performance of the unit, soldering should be conducted as quickly as possible. Recommended Temperature and Time for Soldering Wave Soldering (Noryl, PBT, PPS) 56ºC.within seconds 5ºC.within seconds s Along with other electronic components, these transducers may be washed with cleaning solvents after the soldering process. Most cleaning solvents will be damaging to these transducers, wave soldering & washing should be prohibited. In the view of the recent requirement for total elemination of ozone-depleting chemicals, we have decided to recommend our customers to use deionized water for their cleaning process at the conditions given below, instead of "CFC" that was conventionally used. Cleaning solvent.. Deionized Water Solvent Temperature.. 55 ºC± 5º

4 - As there are differences in the meausring distances when manufacturers make the measurement of sound pressure, the following formula is recommended for calculation on occasions when a buzzer itself is tested or compared with a planned finished product. However, as far as the calculated value is concerned, it is theretical one and therefore subject to change, depending upon circumstances and conditions. The formula is: B=A+ log (La/Lb) the sound pressure variation for reference. measuring distance variation sound pressure variation times -6. times -9.5 A : Sound Pressure Value at distance La Ex. When the distance is doubled, B : Sound Pressure Value at distance Lb B=A+ log (la/lb)=a+ log (/) =A - 6. i.e. the sound pressure is apt to be reduced by 6. db. The table below is to shape up relations between the measuring distance variation and times -. 5 times times Measuring distance variation (times) 7 times 8 times 9 times times The tone output, generated by buzzers, is essential in product design. A recommended way of selecting a desired tone is by listening to the different tones produced by the different buzzer. Additionaly, FFT analysis is usable for visual tone selection method. The sound is not an oscillation of a single frequency, but as a collected body of individual frequencies. The analysis is to diagnose the ratio of constituent frequencies. The following is a sample analysis of our typical buzzers. db DBE8 type FFT analysis K DBE8 type A weighted network Distance cm k Element with Feedback Tab: This type of element has a tab form on the ceramic part. It used as the feedback function in a simple oscillation circuit, it will create a back voltage, or back EMF. to the internal circuit. Thus, the element operates automatically at the natural resonant frequency of the element and the loudness sound can be obtained. To fix the edge of the element to the supporting ring of the case. SPL depends on input frequency. However, considerable sound pressure can be obtained covering a wide frequency range around the resonant frequency. To fix the nodal diameter of the element to the supporting ring of the case. Loud sound pressure can be obtained at the resonant frequency. The SPL will drastically drop when the frequency is not at resonant point. This is the high efficient type of mounting for feedback type element

5 Housing Housing Piezo Element Piezo Element Silcon Rubber Silcon Rubber Leadwire Leadwire Our line of Wide Range Piezo Transducers offer the signalling and alarming transducer at a cost effective price. Our extensive line of transducers include devices that are sealed for washing, have different mounting type include, Flange mount, PCB mount, panel mount, plate mount and SMD mount. Piezoelectric Ceramic buzzer element have a simple structure in which piezoceramic element is gluded to vibration plate. When alternating voltage is applied to piezoceramic element, the element expands or shrinks diametrically. This utilized to make vibration plate bend to generate sounds. The acoustic generating method can be roughly divided into self-drive oscillation method and external drive oscillation method. The former shows the lowest impedance on the acoustic generator, and produces the sound by the positive feedback oscillation circuit to make resonance. Thereby, big sound pressure can be obtained by a simple circuit. While the latter selects an optional frequency and makes sound by the nonstable multivibrator, and it is used for the case having the oscillation Ceramic Metal Plate circuit. External-drive Oscillation Circuit Power source This method is to fix the outside circumference of the buzzer element to the supporting ring of the plate. Considerable sound pressure can be obtained covering a wide frequency range around the resonant frequency. Self-drive Oscillation Circuit Power source This method is to fix the nodal diameter of the buzzer element to the supporting ring of the plate. Loud sound pressure can be obtained. Flexible adhesives, such as silicon rubber, should be used between the buzzer element and the support ring.