FAQ:
Q: Why are you so obsessed with your dog?
A: Polly is my friend's dog...
Q: What is V = IZ?
A: That's Ohm's law. You're probably familiar with it as V = IR. But, that's only true in the DC (Direct Current) domain. Z is how impedance is written in the AC (Alternating Current) domain . In the case of inductors and capacitors, the impedance can be complex.
Q: Complex as in complicated?
A: Not necessarily. Actual complex #'s. A capacitive load could be written 1 - 1j and an inductive load could be written 1 + 1j. The first part of the equations is called the real part, and is the resistive (heat dissipative) component of the equation. j is how electrical engineers write i, which is the square root of -1 and represents the power that is stored either electrically (capacitors) or magnetically (inductors.) Note that the imaginary axis is orthogonal to the real axis, which means that knowledge of either axis conveys no information about the quantity of the other axis. This is the only physical use of complex numbers that I am aware of.
If that twists your mind, then how about this? At high frequencies, capacitors become inductors and vice versa... You can even match a load by adding a stub, which is an additional wire that doesn't go anywhere. It's true. Read about the Smith Chart if you don't believe me.
Q: So, you used V = IZ throughout your career?
A: No, the web domain is ironic (and V = IR was taken.) I would guess that I only knew V = IZ three times in my life. First, during college emag class (1996.) 2nd: when I took my professional engineering exam and registered this website (2012.) 3rd: when making this website (this year.) The rest of the times, which is by far the bulk of my career, I didn't know it or maybe would have thought it was only true in special cases.
In the USA, where I worked almost my entire career, people don't distinguish between electrical and electronics engineers. But, outside of the USA, the general rule is that electrical engineers work on AC (think power plants) and electronics engineers work on DC. My whole career was basically in electronics, so DC. This is why AC Ohm's law was basically unknown to me.
Q: Is this a consulting website?
A: No, this is a personal website that isn't indexed by the search engines. However, it contains a lot of the concepts that I plan on using in my consulting career, so I may link this website with my consulting website from time to time.
Q: Do you have any clips?
A: Yes
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