Just have a question: how can I make a steady temperature to heat water or liquid where I have 5 volts with 2 or 3 grounds as a source only? Please explain the things that can be required to increase things such as resistance and current and their source such diodes or batteries with the require volts or any such stuff. Want to heat water or other liquid. Have only 5 volts and 2 or 3 grounds. Please explain the things how to get the standard volts , current and resistance ratio such as the supply to our homes through 5 volts and 2 or 3 grounds as my source which after assembled and good enough to heat water or liquid.