I recently designed a power supply that was good for about 700mA power and used these diodes https://www.diodes.com/assets/Datasheets/ds28002.pdf They are 4007 diodes. As I am checking the datasheets for my 5A power supply I'm noticing that they are good for up to 1A so I was wondering which diodes are commonly used with high amperage 50 Hz / 60 Hz power supplies? What other components can I expect to change with this change in amperage? Looking forward to your responses

EDIT: this is a standard 50Hz / 60Hz power supply .. buck converter becuase it's high amperage. That is what i'm referrring to in this question, as replacement for 1N4007 diode.

I am also making a different 5A power supply.. which in this case requires Schottky diodes rated for high frequency and 3-4A, in a full bridge rectifier


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    \$\begingroup\$ Your question does not make it clear whether you are designing a 50 / 60 Hz power supply or an SMPS. What exactly do you mean by "... to instead rectify the voltage BEFORE it goes through the transformer."? \$\endgroup\$
    – Transistor
    May 26, 2020 at 10:29
  • \$\begingroup\$ rectifying AC to DC before it passes through the transformer. ( using a diode that can do 1A at 120V at the start of circuit instead of using a diode that does 3-4A at 5V after the voltage has been stepped down.) - using these in a full bridge \$\endgroup\$ May 26, 2020 at 10:57
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    \$\begingroup\$ Notice that you didn't answer my question regarding mains frequency or SMPS. You are aware that transformers work on AC and not DC, aren't you? \$\endgroup\$
    – Transistor
    May 26, 2020 at 11:23
  • \$\begingroup\$ only slightly confused. Appreciate the comments. i saw briefly something like that circuit rectifying 120V AC to 120V DC before passing through transformer so i was referencing it. Transformers only transform from AC. \$\endgroup\$ May 26, 2020 at 11:36
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    \$\begingroup\$ Your question is still very confused but you have accepted an answer already so it is unlikely that anyone else will try to answer. \$\endgroup\$
    – Transistor
    May 26, 2020 at 12:11

1 Answer 1


1N540x is a common 3A diode, so with a full bridge you can get 6A. Above a few amperes you should consider Schottky diodes, at least at lower supply voltages.

You can also get inexpensive packaged bridges with ~17A diodes rated for 35A that can be directly bolted to a heatsink.

  • \$\begingroup\$ schottky diodes are what i am going to use before the flyback transformer. Was thinking about the switching speeds, because i am planning to use high frequency. this is what i have in mind for either application. These are both for AFTER the transformer (40V max) mouser.com/datasheet/2/348/rbr5lam40atr-e-1801371.pdf and 5A each (10A max load) \$\endgroup\$ May 26, 2020 at 10:19
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    \$\begingroup\$ None of these are acceptable for much higher than audio frequencies. Ultrafast and Schottky diodes are required for reasonable efficiency at tens of kHz and higher. \$\endgroup\$ May 26, 2020 at 10:21
  • \$\begingroup\$ Exactly, i may not have been clear about that understanding. the linked is a Schottky diode \$\endgroup\$ May 26, 2020 at 10:22

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