so I need a power source for a 3.3V Esp8266 which is gonna be connected to a dht22 to report temp Data to a server. I've got the code up and running, just need to throw in a esp wdt.

Looking for a standalone power source I was first suggested an MCP1700. For some reason I posted about it in the Arduino forums and was suggested a lm1117 instead because of the quiescent current superiority.

So I'm ordering it but I remembered I had other voltage regulators and indeed found:

Some lm7805 which I know are for 5V

Some amc7135 which is a current regulator

Some lm317, which are variable voltage regs. Could I use these? What would be the pros and cons vs the lm1117?

 

What would be the pros and cons vs the lm1117?

The main difference is dropout voltage.
It is 1.2V for the lm1117 and about 3V for the LM317, so it depends upon the supply voltage that powers the regulator as to which one you can use.
The LM1117 would require a minimum of 4.5V supply voltage (allowing operation from a standard 5V supply). and the LM317 a minimum of 6.6V.

 

Woah so the lm1117 would indeed result in less wasted energy!

 

Woah so the lm1117 would indeed result in less wasted energy!

Only if you operated it from a lower supply voltage.
There would be no difference if they both operated from the same voltage (assuming it's equal to that needed to operate the LM317).

 

OK here's why u thought what I said:

The lm1117 would require 4.5V to supply 3.3V (1.2v extra) vs the lm317 which would need 6.6v (3.3v extra).

 

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The lm1117 would require 4.5V to supply 3.3V (1.2v extra) vs the lm317 which would need 6.6v (3.3v extra).

If operated from those two different voltages then certainly the LM1117 would be more efficient than the LM317.