Hello, I have a 24V fan that i want to toggle with a esp32. I have a power supply of 24V. I guess i would need a step down converter to power the esp32 and a replay to toggle the fan. Can somebody share any schematic or point to a relevant project?
Easiest way would be Shelly Plus 1, it works at 24VDC out of the box. I warmly recommend.
Otherwise you need stepdown or separate power supply (usb charger for example) for Esp32 and 3.3V relay module.
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If this fan is part of an hvac unit it’s likely 24VAC not DC. It doesn’t seem like the shelly can be powered by a 24VAC input.
I wrote 24VDC.
Neither stepdown converter can be powered directly from AC.
Shelly Uni can be powered from 24VAC, but it can switch only very moderate loads, ~300mA.
- ESP-01 + ESP-01 relay (10A) ~USD$2.50
- Step down power supply ~USD$2.00
You’ll want a case. Free, if you use an yogurt container of something like that.
If you really want to use your ESP32, you could wire into the ESP-01 relay board.
I haven’t used and ESP32, but an ESP8266 requires ENABLE to be wired to 3V3 and a pull-down resistor (10k?) from GPIO15 to GND to start up.
Good project!
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You should! 
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there is no AC involve here. Its PC cooling fan, trying for 3D printer filter.
Thats very interesting. Shelly plus 1 serves all i need but in a single package. thanks.
24VDC right?
yes.
btw does 24VAC exist?
Very common in “traditional” devices. Rarely used in modern ones.