Integrated-Project-2-2021-UVic-UCC / covid-device

This is an integrated project of a COVID device for building access control. It contains the development of the software to control electronical and moving devices.
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Relay powering issues. #25

Closed moises-garin closed 3 years ago

moises-garin commented 3 years ago

Hello,

I believe your relay board use these relays: relay.pdf

The 3.3V version need around 100mA to work. This means you need 200mA to be able to operate both relays.

The internal ESP32 regulator is meant for powering just the board itself, not the external periferals. Somewhere in interned it mentions that you can draw about 50mA from the 3.3V pin. Therefore, I believe your problem comes not so much from the power source, but from ESP32 3.3V regulator limitations. To avoid these problems, you need an external 3.3V regulator and power the relays from that source.

Alternativelly, you could also try the 5V relay module powered from the USB. Hopefully the 3.3V from the GPIOs will be enough to trigger the optocoupler, or use a simple transistor as level shifters.

Best regards.