# Which diodes are used in a high amperage rectifying circuit? (4007 are 1A rated) and other components

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

thanks

• 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."? May 26, 2020 at 10:29
• 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 May 26, 2020 at 10:57
• 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? May 26, 2020 at 11:23
• 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. May 26, 2020 at 11:36
• Your question is still very confused but you have accepted an answer already so it is unlikely that anyone else will try to answer. May 26, 2020 at 12:11

## 1 Answer

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.

• 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) May 26, 2020 at 10:19
• 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. May 26, 2020 at 10:21
• Exactly, i may not have been clear about that understanding. the linked is a Schottky diode May 26, 2020 at 10:22