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I have receiver circuit for a wireless power transfer circuit. I have connected the circuit as shown in the image below. The circuit has a full bridge rectifier (DBS103S-T) which is then followed by a voltage regulator (L5973D) that regulated the voltage to 21.4 V. The voltage regulator is then connected to a current limiter (LT3092EDD).

The circuit works as intended when a power supply is connected to the output end of the full bridge rectifier. That is skipping the whole input from the coil to the full bridge rectifier.

The issue occurs when the coil is connected and flows through the full bridge rectifier. I reach a maximum of 7-8 V with a current output of about 100 mA. The full bridge rectifier gets also very hot, can barely touch it. I tried changing the IC, but i have the same result. I am not really understanding why it’s not working as before when i had tested the circuit with the only the full bridge rectifier (without the voltage regulator and current limiter) it was working fine. Im assuming that there is a possibility of some reverse current/voltage that is causing this issue but I am not sure.

enter image description here

Edit: Added a clearer image.

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  • \$\begingroup\$ Sorry about that, i noticed the image quality being bad after you mentioned it. They are 10µF caps. I am operating the full bridge rectifierat 130kHz. \$\endgroup\$
    – EmeraldMonk
    Commented Jun 26, 2023 at 7:50

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I am operating the full bridge rectifier at 130kHz.

The bridge rectifier is not suitable for high frequency rectification at all. It contains standard recovery (slow) diodes that are not to be relied upon above a few kHz. It's standard application is the rectification of mains AC frequencies i.e. 50 or 60 Hz.

enter image description here

It doesn't even list a reverse recovery time figure in the data sheet as far as I can tell. You need to use rectifier diodes that have a specified reverse recovery time of no more than a couple of hundred nano seconds in your application.

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  • \$\begingroup\$ i had previously used some schottky barrier diodes(RB400VAM-50), would they be a better solution to this issue, or would bit better to look for rectifier specific diodes, and replace it with them. # \$\endgroup\$
    – EmeraldMonk
    Commented Jun 26, 2023 at 9:57
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    \$\begingroup\$ @EmeraldMonk I would avoid packaged bridge rectifiers because they are likely to be low-speed. Schottky should be fine but look out for reverse leakage currents if the circuit gets warm; some are a lot better than others. \$\endgroup\$
    – Andy aka
    Commented Jun 26, 2023 at 10:00
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    \$\begingroup\$ standard application is [mains frequencies] Then again, the datasheet shows capacity@1 MHz… no \$t_{RR}\$, no \$f_{MAX}\$. \$\endgroup\$
    – greybeard
    Commented Jun 26, 2023 at 10:14
  • \$\begingroup\$ @Andyaka, So lower Reverse leakage currents and also better Trr time results in a diode that reacts properly with less heating ? \$\endgroup\$
    – EmeraldMonk
    Commented Jun 28, 2023 at 9:06
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    \$\begingroup\$ @EmeraldMonk correct. \$\endgroup\$
    – Andy aka
    Commented Jun 28, 2023 at 9:13

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