I would just like to question about the components in this circuit because some of the components don't have labels like the value of D3 (are all of the diodes are the same ???) and the unlabeled capacitor after the feedback from the transformer (is capacitor2 and capacitor3 are the same??) . Moreover, I would like to know if there is an alternative component on EDA456 diode and want to know what is its function and specification. Also can I have a suggestion on what particular tranducer model I will use thank you very much!!!^___^