ESP8266 Community Forum

- Wed Sep 30, 2015 12:37 pm #30201

The 1117 has quite high quiescent current (5-10mA) for a battery powered circuits. It means that even if your ESP is in deep sleep mode, the 1117 will draw current. I think the better option would be XC6203 or MAX604.

MCP1825s

And by the way, in case of RTC hardware power management solution, if all is OFF except a 10uA RTC , it really doesn't matter so much if you use the 1117.

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/

- Fri Oct 02, 2015 7:25 pm #30391 Regarding the MCP1700, I am using it successfully and having no problems. It is supplied from 3xAA NiMH that start with about 4.5V. It is important to put a hefty cap (I use 470uF low ESR) on the ESP or it will have major issues.

Low self-discharge batteries help too for long running set-ups.

I should also mention that newer modules seem to have lower deep sleep current, I measured a recent 12e at 17uA (older ones were 22-30uA and a very old esp-12 uses 120uA!). While this may be the processor, it could equally be the quality of the flash.

- Sat Oct 03, 2015 12:00 pm #30421

Thanks very much for the comments. As a result, I have done some homework and redesign using a TC1262 LDO (500 mA) and a LP0701 P-channel MOSFET.

For the regulators, I obtained the TC1262, MCP1825s, and MCP1725. All three are 500 mA and they have similar specifications in my view. The MCP1725 has a “power good” output that may have some uses. For now I am using the TC1262. All three have a 6 volt input limit and if I move from 4X AA 1.2 NiMH batteries to 1.5v alkaline, I will use 3X AA to keep the input voltage away from the limit.

Learning about the MOSFET replacement for the PNP has been challenging and some of it is starting to make sense. I chose the LP0701. Key specifications for me: Id, -500 mA; Vgs~0.7v.

I have not put capacitors in the schematic but will be using them before and after the regulator. I will also test a higher value resistor for R1 (2.2k-4.7k).

The new version of the circuit appears above. It has been bread boarded and is testing just fine. But it is a limited test – I am simply turning on an LED for 5 sec on an alarm occurring every minute. After I do some more coding with the RTC, I will start to move it to an ESP8266 and move forward.

Again, I very much appreciate the feedback and please do comment further if the mood strikes you.

Cheers,
DrG

Last edited by DrG on Sat Oct 03, 2015 12:43 pm, edited 1 time in total.

- Sat Oct 03, 2015 12:11 pm #30425

Regarding the MCP1700, I am using it successfully and having no problems. It is supplied from 3xAA NiMH that start with about 4.5V. It is important to put a hefty cap (I use 470uF low ESR) on the ESP or it will have major issues.

Low self-discharge batteries help too for long running set-ups.

I should also mention that newer modules seem to have lower deep sleep current, I measured a recent 12e at 17uA (older ones were 22-30uA and a very old esp-12 uses 120uA!). While this may be the processor, it could equally be the quality of the flash.

i have mcp1700t and i am reading 3ma on deepsleep. i am reading 3ma even module not connected. my mcp1700t not working correctly or anything else?

ESP8266.com Moderator
Lets get the party started and +1

[url=https://www.banggood.com/custlink/KvGGhGF4wG[/url]

I like ESP8266 and ESP8285 and ESP32