David Swinscoe's Electronics Pages                 Diodes

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Germanium diodes are used for detectors in radio circuits because they only require a small voltage to make them conduct so they do not lose too much of the radio signal. However, germanium has a low melting point so they cannot handle large current.

Silicon diodes are used in most circuits that require the current to flow only in one direction. Diodes are chosen to handle the forward current that is required and the reverse voltage they need to withstand.

Device Part number Picture Datasheets
Silicon - Low current 1N4148 Fairchild Semiconductor
Silicon - Medium current rectifier 1N4001 Fairchild Semiconductor
Silicon - High current rectifier 1N5401 Fairchild Semiconductor
Germanium - For radio detector circuit OA90  

Zener diodes are used to produce fixed voltages.
Device Part number Picture Datasheets
2.7v Zener BZYC2V7 Philips semiconductors
5.6v zener BZYC5V6 Philips semiconductors
12v zener BZYC12 Philips semiconductors