ESP8266 Community Forum

- Sat Feb 20, 2016 11:01 am #41512 I recently soldered together my first ever PCB. To power the ESP-07 I used a 9V 1A adapter, and a LM1117 to get 3.3v.
Everything works like a charm now, but I noticed the LM1117 is getting extremely hot, I can't even touch it for a long time without burning my fingers.

Since I want to build the pcb into a plastic box, I was wondering if I'm not creating a fire hazard here...

Is it normal for the LM1117 to get hot? Would if be sufficient to just stick a heat sink onto it, or are there better ways to provide power to the ESP?

- Sat Feb 20, 2016 11:53 am #41515 Linear regulators have to ditch unwanted Volts*Amps as heat. Yours is having to ditch around 1 Watt because the 9V PSU is 5.7Volts too many. If it was a 5V PSU it would only have to lose 1.7V
1 Watt may not sound like much but in a tiny SMT package it's going to fry.

- Sat Feb 20, 2016 12:10 pm #41519 Thanks for your explanation, that makes sense.
I think I will order a 5v adapter then, combined with a heatsink on it, that should do the trick I guess.

- Tue Feb 23, 2016 6:37 pm #41763 Hey ErikLem Congratulations on your first self soldered PCB. That's a great accomplishment in my book! Good luck with all your future projects.

Learning a little more every day.