ESP8266 Community Forum

- Sun Apr 01, 2018 9:16 pm #75071 Read up on this. It gives you the ability to adjust cut out/in voltage.

https://electronics.stackexchange.com/questions/213304/tl431-low-battery-cut-off

- Mon Apr 02, 2018 3:20 am #75075 unfortunately these circuits consume considerable current and may not produce needed steep ramp. With 3.3V supply this will be even harder.
I'd rather look for something like STM/MIC 809/811, MIC803-31 etc (and they are even cheaper than the LM431 alone)
remark: make sure to keep an eye on the datasheet concerning EN/RST sequence and timings ...

- Fri Apr 13, 2018 3:40 pm #75353 Well well well,

I did some preliminary tests and I'm not very convinced I'll be able to reach my goals which to do it with "recycled" solar cells from dead garden lights.

The most convenient ones I have are TRONY sc3939s : as per the specs, they can deliver about 30 mA within the best conditions.
So, to have an acceptable power, I'll need 6 cells (to reach more than 3v and 100 mA, again with the BEST conditions).
But Wifi is very power hungry and I'm not sure even 3x2200uF will stand enough.

If my tests fail, I'll probably test with better cells, a regulator and perhasp a "super capacitor".

Bye