Hey guys,
When I wanted to power my ESP8266 with 3.3V, I was using the tension regulator MCP1700. Now I need to power my ESP32 with 5V using two 18650 batteries (max voltage 8.4V). Could you please tell me which LDO would be the best to use? I was thinking of the LM7805? Is it ok? I'm sure there's something better.
Thanks for your help
Laurent
The LM7805 is not a LDO regulator.
Oh yes, it's not an LDO! What about the HT7150-1?
The MCP1700 is a CMOS low dropout positive voltage regulator
not a tension regulator.
Ok, I understand. But can you please help me for the 5V tension regulator?
I'm trying to find something better than the one I'm using now :
Thanks a lot
I was just following this :
I might be wrong but it's working fine.
Now you are using a DC DC regulator and want to replace it with a linear regulator? Why? The DC DC regulator is much more efficient and with the linear controller you have large losses, accompanied by large heat dissipation. In this video, they use an one 18650 battery and probably use LDO for that. You are using two 18650 batteries connected in series and I think adding a linear regulator is a bad idea.
Ok then, I will stay with the regulator I use. I'm a bit limited with space and I thought there was something smaller.
Thanks for your help
What is a tension regulator ?
Never heard of it,
Is that s language translation error ?
voltage regulator, sorry. English is not my first langage
Yes, "tension" is an old name for voltage. The leads connecting the spark plugs to the distributor in an internal combustion engine are often called "high tension leads" for example. Tension may be the literal translation of voltage from some languages into English.
@ponpon777 why are you using 2x 18650? Does your circuit need > 3.7V for some other component?
There are significantly smaller dc-dc convertors available than the one you are using. You should not need much current to power an esp, 5A is ten times more than you require.
I need 5 V for my sensors. I tried 3.3V but doesn't work.
Which smaller DC-DC convertors would you recommend?
Why didn't you say you were looking for a smaller alternative? See boards similar to the mini 360 converter. Also, if the converter is for a fixed voltage it is usually smaller in size.
Can you find equivalent 3.3V sensors?
Can you use 4x AA or AAA NiMH instead of 18650? 4x NiMH will give close enough to 5V that no regulator or converter will be needed, and that is more efficient.
No equivalent 3.3V sensors.
Good point! Is the voltage stable enough? There need to last for a few month (with deep sleep mode of course).
Stupid question: if these battery are 1000mAh, I don't think I will have 4000mAh, right? 
No, when your connect batteries in series, you increase the voltage but the capacity remains the same. 4x 1.25V, 2000mAh will give you 5V, 2000mAh.
I would go so far as to say 20 times
For what? You have not told us what these mysterious sensor are.
The voltage direct from any battery will vary somewhat from fully charged to discharged. But many "5V" devices will operate in a range of voltages, for example 4V to 5.5V, so will continue to operate over the voltages that your battery provides.
To power your esp from 4x NiMH, an mcp1700 regulator is perfect.
Oh, I forgot to say, most NiMH cells will self-discharge over a few weeks. You must use the "ready-charged"/"stay-charged"/low self-discharge type.
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