Hi all!,
I'm triyng to power a Wemos D1 mini board from 2x AA batteries. I need 5v because there are another parts on the circuit than need this voltage (The Wemos d1 can be powered by 3,3V input or by 5V input. In the 5v input it has a 3.3v regulator)
I tried 2 ICs, the HT7750 and the MT3608. Booth gives 5v whitout charge, but when connect the circuit the voltage drops. The board need a pick of about 200mA when starts, but in the sketch I disconnect the Wifi from the board, and the current drops to 35mA.
Maybe this initial peaks is the problem?
Anyone knows something to boost from 2-3v to 5v 200mA?

 

Plenty of boost converters advertised online, e.g this one.

 

Hi all!,
I'm triyng to power a Wemos D1 mini board from 2x AA batteries. I need 5v because there are another parts on the circuit than need this voltage (The Wemos d1 can be powered by 3,3V input or by 5V input. In the 5v input it has a 3.3v regulator)
I tried 2 ICs, the HT7750 and the MT3608. Booth gives 5v whitout charge, but when connect the circuit the voltage drops. The board need a pick of about 200mA when starts, but in the sketch I disconnect the Wifi from the board, and the current drops to 35mA.
Maybe this initial peaks is the problem?
Anyone knows something to boost from 2-3v to 5v 200mA?

A real easy dodge is to pinch the board out of a cheap power bank. You'd need 3 cells or a single lithium that could easily be smaller.

The £ store where I am has them.

 

I used this chip in several projects.
I advise you to use a capacitor of at least 100μF at the output.
See

 

Try this:

Or look up any other module in google for 3 to 5V boost module or 2 to 5v, whatever you want. They cost about 5 dollars without the delivery.

 

I have tested this and it works. The problem is that the phone gets charged very slowly if it is on.

https://circuitdigest.com/electronic-circuits/power-bank-circuit

 

I have tested this and it works. The problem is that the phone gets charged very slowly if it is on.

https://circuitdigest.com/electronic-circuits/power-bank-circuit

My power bank idea should be compliant with the 5V 500mA USB standard (which most phones are compatible with) pay a bit more than the £ store and it might be good for a couple of A.

 

The standard is 5v/1A.

 

The standard is 5v/1A.

maybe now...………..

 

I think of making such a PCB, but it will be when I can.