Average Consumption Current
The average consumption current (mA), is described in the form of MAX.xx. This means that, if the rated voltage is applied without limiting electric current, the average current value will not surpass xx mA. Be careful, as it is not meant that electric current exceeding xx mA must not be applied to the product. In reality, maximum current 2 to 3 times higher than the average current is required as peak current. Therefore, a driving current that can supply sufficient current should be provided. If the peak current is restricted, there can be a case in which sound pressure will not be output as specified.
(Example) In the case of FZ111A, whose average current is MAX. 10mA, prepare a driving circuit that can supply the peak current of at least 30mA.
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. Additionally, 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 buzzer.
Points of Attention in Setting an External Resonator
Based on the aforementioned experimental example, the resonance effect of Helmholtz and its significance are believed to be understood. Points of attention in setting an external resonator are as follows. 1) if the sounder has a resonator of its own, there is a possibility that the theoretical value of the relational expression in Fig. 8 and the real measurement value will be substantially different, as the resonator or the sounder and the external resonator combine acoustically. In this case, it is necessary to adjust the actual equipment of the external resonator, attaining optimization. 2) To ensure the resonance effect of the resonator, it is necessary to reduce the sound resistance of the sound emission hole. If the sound emission hole of the external resonator is reduced too much, however, it is possible that no satisfactory outcome will be produced, even if the same frequency is set.
The sealed miniature sound transducers by Star should not be exposed to extremely high temperatures for prolonged periods of time. As excessive heat will degrade the sealing performance of the unit, soldering should be conducted as quickly as possible.
Recommended temperature and for soldering:
250°C ……… within 5 seconds
350°C ……… within 1.5 seconds
● Dip soldering
Dip soldering may be conducted only in the case of washable products. As for non washable products, dip soldering should not be implemented.
(1) Washable type transducers.
Along with other electronic components, these transducers may be washed with cleaning solvents after the soldering process.
(2) Non-washable type transducers.
Subsequent mounting is recommended to avoid to be washed. If it is inevitable to wash a transducer, take necessary measures to prevent washing fluid from entering into the transducer. And it is also required to ensure well ventilation to avoid any undesirable effects by the component substances of the flux that may otherwise remains in the atmosphere.
Flux Removing Solvents
In view of the recent requirement for total elimination 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.
Conditions for cleaning :
Cleaning solvent ……… Deionized water
Solvent temperature ……… 55 ± 5°C
immersion time ……… 5 ± 0.5 minutes
For further details, feel free to ask us directly or any of our distributors.