To calculate the change in temperature, subtract the initial temperature from the final temperature. Example: 84.2 degree Fahrenheit - 41 degrees Fahrenheit = 43.2 degrees Fahrenheit. The temperature from morning to afternoon changed by 43.2 degrees Fahrenheit.
It needs 12 volts so it will be the standard modern power supply provides 12 volts of power.
Electrical systems based on 12-volt batteries can be used to supply 110-volt AC (alternating current) through the use of a voltage inverter. These devices can provide normal house current from a variety of 12-volt DC (direct current) sources, including your automobile cigarette lighter.