I'm building a little circuit to handle two 5m led strips with an ESP32. ESP32 is a d-duino-32 OLED clone you can find in ebay/aliexpress sites.

Also bought a 5v 20a power supply. One path powers the esp32 with a 1000uf capacitor and a 1ohm/5.1v zener diode. The other path goes directly to both strips with a 2000uf in the middle.

The first time I turn on, I see on OLED display info I programmed. Leds are off because didn't programmed the code yet. If I turn off and on again, I can measure the correct voltage but ESP32 does not start.

If I turn off again, wait some minutes and turn on again, works again.

If I remove the led strips, works always.

It is supposed the 20A power supply should be enough to handle the 300 leds x 60mA each = 18A plus ESP's 500mA although all leds are off initially.

What can cause this to fail?


Circuit: Circuit Photo: enter image description here

  • 1
    \$\begingroup\$ Draw a circuit and post it. Don't expect others to interpret your words consistently or correctly. \$\endgroup\$
    – Andy aka
    Jan 24, 2018 at 12:17
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    \$\begingroup\$ yep, and not only draw a circuit. At such high currents, the actual wiring becomes a resistive element, and plays a role in the circuit, so please also add a photo. \$\endgroup\$ Jan 24, 2018 at 12:19
  • \$\begingroup\$ Done, photo and circuit uploaded \$\endgroup\$ Jan 24, 2018 at 13:05

1 Answer 1


Replaced capacitors with lower ones (10uF/100nF and 470uF) and problem solved.


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