I have an LED flashlight that runs on 3 AAA batteries.

I want to run it with a 12 volt battery.

I have adjusted a dc to dc converter to 4.2 volts.

The flashlight gets very hot. (It doesn't get hot when the AAAs are connected)

I've checked my volt meter to see if the dc to dc converter was adjusted correctly, and it seems to be.


What am I missing? Why does it get hot on the 12 volt battery power?

Thanks