Let%27s explore the typical current ratings for bridge rectifiers in detail.

1. Continuous Current Rating:
- The continuous current rating specifies the maximum average forward output rectified current that the bridge rectifier can handle.
- It is typically measured at mains frequency (50 Hz or 60 Hz, depending on the region).
- The limiting factor for the current is thermal—many bridges specify a certain current but mention it with specific conditions, such as "with a particular heatsink, at 25°C."

2. Choosing the Right Diode Current Rating:
- When selecting a bridge rectifier, consider the load current and supply current requirements.
- The load current should not exceed the continuous current diode rating.
- For example, if your power supply design requires a 3A output, choose a bridge rectifier that can handle at least 3A of current.
- Similarly, ensure that the supply current does not exceed the diode%27s current rating, even momentarily.

3. Example Calculation:
- Suppose your output voltage is 18V DC (converted from 110VAC).
- The RMS value of the transformer%27s secondary voltage (before rectification) is approximately 14V.
- Applying the ×3 rule of thumb (which refers to the transformer%27s secondary voltage), we get:
- 14V × 3 = 42V (maximum headroom).
- Subtracting two diode drops (around 0.6 to 0.7V each), we arrive at 18V.
- Therefore, any of the rectifiers you mentioned—35V/10A, 50V/2A, or 60V/4A—will work well for your 18VDC/1A power supply.

4. Surge Ratings:
- Keep in mind that some bridge rectifiers have surge ratings much higher than their continuous ratings.
- For example, many "4 amp" bridges may have a surge rating of 200 amps.

In summary, consider both the continuous current rating and any surge capabilities when choosing a bridge rectifier for your specific application¹²⁴.


(1) diodes - How are bridge rectifiers rated? - Electrical Engineering .... https://electronics.stackexchange.com/questions/37401/how-are-bridge-rectifiers-rated.
(2) What should I consider when choosing the right diode for rectifiers .... https://www.circuitbread.com/ee-faq/what-should-i-consider-when-choosing-the-right-diode-for-rectifiers.
(3) Bridge Rectifier Current Rating -- How much is enough?. https://www.electro-tech-online.com/threads/bridge-rectifier-current-rating-how-much-is-enough.2523/.
(4) Bridge Rectifier Calculator. https://www.omnicalculator.com/physics/bridge-rectifier.
(5) Diode Ratings | Diodes and Rectifiers | Electronics Textbook. https://www.allaboutcircuits.com/textbook/semiconductors/chpt-3/diode-ratings/.

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