I like watching science videos on YouTube and I have a very basic understanding of electronics. But I never seem to get the “negative voltage” thing.
Why is it used and how does it differ from normal voltage.
In: 5
Voltage is measured as a difference between two points. What you choose to be zero is entirely arbitrary. Negative voltage is simply any place where current would want to flow from zero to that point. If I had a car battery (12V) I could say that the positive terminal is 0V and the negative terminal is -12V and all the math works out the same. I can also say the negative terminal is 100V and the positive terminal is 112V and still nothing changes. In all of these situations, the voltage across the battery is still 12V. Just choose an easy place to put 0 to simplify the math you have to do.
If you’re doing electrostatics, it’s easiest to make 0 be an infinite distance away so you don’t need to constantly adjust for your arbitrary 0.
Electromagnetism can attract OR repel, if you have elementary particles that have a negative charge (electrons for example) they will repel other electrons, but attract particles of positive charge (protons in the nucleus). Bottom line, there are elementary particles that have this “charge” property that can be positive OR negative, so all of our electronics have to “deal” with positive and negative voltages, because the elementary particles that we use have these fundamental properties.
As a contrast, elementary particles either have mass or don’t; a “negative mass” particle has NOT been observed. So gravity only attracts, it never repels, and if you could somehow make a “gravity” circuit you would only deal with “positives”.
As another contrast, protons and neutrons are made of 3 quark particles inside them. These quark particles have a property called “[color charge](https://en.wikipedia.org/wiki/Color_charge)”, which can be red, green, blue (and anti-red, anti-green, and anti-blue). So it’s a three-way system, you don’t just have attraction or repulsion like with electromagnetism, you have a more complicated force interaction (the nuclear force).
Anyway, in terms of electronics, the voltage is the “pull”, the thing that makes the electrons want to move in a direction. Kinda like the pull of gravity, but for electromagnetism it can be a pull (positive voltage attracts electrons) or a push (negative voltage pushes away electrons).
it doesn’t differ, the reference is just different.
e.g. you have a set of stairs with 10 steps, it is both 10 steps up(+) and 10 steps down(-), it depends on whether you are standing at the top or the bottom of the stairs
It’s a bit like saying sea level is -9000 meters (well, more or less) with respect to the summit of the everest.
Latest Answers