The specific colours of brown and blue suggests that this is a question from the UK or European area. On checking the IP address it shows that the question comes from Uruguay. 110 volts is not a common voltage to this area, so that 110 volts can not be converted to 220 volts because 220 volts is the common working voltage. If the question is asking about using 120 volt equipment in that country see related links below.
If you are connecting 120 volts, you connect the black wire to the breaker, white wire to the neutral bar, and ground wire to the ground bar. If you are connecting 240 volts connect the black & white wires to the breaker, & ground wire to the ground bar.
A power supply receives 120 volts of AC power from a wall outlet and converts it to 3.3, 5, and 12 volts of DC power.
Brown black and ground (yellow=green). The brown and black can alco be black and blue and brown and black
Connect two 12 volt batteries in series and you will have 24 volts.
A crab adapter converts the crab from 120 volts to 220 volts.
A transformer that reduces voltage is classed as a step down transformer.
Connect the two 12 volts batteries in Series. Battery 1 & 2. Connect the negative post (-) of battery 1 to the negative (-) ground cable. Then connect the positive (+) post of battery 1 to the negative (-) post of battery 2. Connect the positive (+) post of battery 2 to the positive (+) cable. You now have 24 volts as the batteries are wired in series.
There is 220 volts between the two poles. If you are running 2 wires (black and white) + ground then you hook black to one pole and white to the other. Put red or black electric tape on each end of the white wire and wrap around wire for 3 inches or so next to the connection so the next person will be able to see that the wire is hot and not a neutral.
That Thermostat is LOW voltage. IT does not have a ground wire. There is no need for a ground. it only opperates on 24 volts. there may be a green wire but it does not mean it is a ground
No, it must be charged with a battery charger plugged into 120 volts AC which converts it to 12 volts DC.
No.
Actually, if you connect the above described LED to 220 V, it will immediately burn out then the circuit will be "open" and the resistance will be "infinite".