Dual Voltage Supply (9V batteries)
Learn how to connect two 9 volt batteries to get:
-9V 0V +9V
Simple 5 minute newbie special.
FYI: Why is negative voltage necessary anyway? Negative voltage is not all bad. Yes, if you switch the orientation of a voltage source to negative polarity for many circuits, the circuit may not work anymore, but in other circuits that require negative voltage it has extreme use and the circuit cannot work without it. One example of an electronic device that many times uses negative voltage is a transistor. Dual op amps need both positive and negative voltage to work. *Note 0V is not the same as -9V. 0V is considered ground any other voltage is positive or negative.
I wonder if that's where they get the phrase "Let's start from ground zero." :)
Step 2: Battery connection
If a battery has positive orientation, its voltage with respect to ground is more positive than ground, and it delivers current to the positive part of a circuit.
If a battery has negative orientation, its voltage with respect to ground is more negative than ground, and it delivers positive current to the ground part of a circuit.
Guest blogger wanted!