What Diodes?

[Electroenthusiast]

What diodes are used for Voltage Rectifier (so has to withstand high Reverse Voltage and Forward current)?
How are those Diodes Chemically different?

And why there is a limit in output current of AC adapter/Voltage rectified circuits?
(Ex: I Max = 500mA)

 

[MikeMl]

1N4000 to 1N4007 are common rectifiers.

The current limit on most wall warts is due to (I^2)*R heating of the transformer.

 

[Hero999]

The current rating is down to the power dissipation which is dependant on the amount of heat the component can get rid of before it gets too hot.

A low current rectifier diode has thick leads which act like a heatsink and dump heat into the board. A larger rectifier diode will require a real heatsink.

A Schottky diode will generally be able to handle more current than a silicon diode in the same package style because it has a lower voltage drop for a given current.