ESP8266 Community Forum

- Thu Jun 22, 2017 1:35 pm #67475 hi guys, in datasheet of AMS1117 3,3v regulator, max Vin is about 10V, but in some nodemcu informations say "Max Vin = 20v". i put 12v and work normally, but regulator is heating a little more.. i need no know if it's SAFE to power NodeMCU by 12v Power Supply

- Thu Jun 22, 2017 5:33 pm #67479 What data sheet tells you it can only have a 10 volt input? The data sheets I looked at says more.

Input voltage is only one thing you have to take into account. Current at that input voltage is another. It can not supply high current at it's maximum voltage. You have to take into account power dissipation, temperature rise.

- Fri Jun 23, 2017 1:19 am #67481 It's better to use a switchmode PSU to convert from +12/24Vcc to 3.3Vcc for many reason starting with efficency and ending with power dissipation.

Or if you need a extremely low noise solution, in 2 stages, first +12/24Vcc to 5-6Vcc SWPSU and after that with a linear regulator to 3.3Vcc.

Example of such a power supply here: Synchronous step-down DC-DC converter

ESP8266 MPDMv4 AC MAINS Dimmer Home: http://esp8266-projects.com/2016/04/mpdmv4-mains-dimmerswitch-html/
Available on Tindie: https://www.tindie.com/products/nEXT_EVO1/universal-ac-mains-dimmer-mpdmv41/

- Sat Jun 24, 2017 12:10 pm #67541 well, i used 12v in Node. Worked, but regulator heating a little, then i made an power supply with l7805 + passive dissipator, this worked very well and not heating!

Here some images! I made this with L7805, 470uF eletrolitic, 100nF ceramic and one passive dissipator from old mother board.

OUTPUT is: 12V, GND, 5V