I'm putting this here so it does not get misplaced.
Tuesday, August 31, 2021
Monday, August 30, 2021
Consider the dualities. The opposites. What can we say about them? light - dark E field - H field particles at rest or in motion.
Consider EMF, current, B and motion.
Can we have any of them without the other?
Suspend a wire in a H field and send a current threw it, it will try to move.
Suspend a wire in a H field and move the wire OR magnet, you will produce current in the wire.
Passing a current threw a wire produces a magnetic field. Can we have a magnetic field without current flow?
Consider the permanent magnet. It has closed loop currents in it structure which create the field.
Question: Can we have a "permanent E field"? Not a trick question so disregard a charged capacitor and the Lydel jar.
A bar magnet has a "permanent H field".
Can we have a "bar ????" with a permanent E field?
What if we melted a bar of wax and placed it in a strong E field and let it cool. Would the field effect the wax?
Can I use wax as the dielectric in a capacitor? Yes of course I can. Will it make a stronger capacitor? Yes it will. Again, what happens if I melt the wax and let it cool while holding a charge on the capacitor?
Hint: Consider the Electret Microphone.
Notice the relationships in the right hand and left hand rules are all at 90 degrees. Also note one component is force/motion. With a generator we turn the armature to create current. With the motor the current causes the armature to spin. Can we have motion without a spinning armature? Consider the transformer. The motion in the primary is "current" flow. The motion in the secondary is also "current flow.
Note: In the beginning (when I was young) it was "H" field and "Cycles Per Seconds". Today they prefer "B" and "hertz" so I may at times use an unfamiliar term. I will even switch back and forth now and then.
LDO low voltage - pinned vs surface mount components
I was planning a single cell radio. The previous oscillator was looking good but will need a little more thought. In the mean time I am looking at the LDO for the single cell radio. My parts bin is fairly well stocked but I am having to decide between surface mount, pinned component or using 3 volts? (the original plan was 1 cell) This series of post show the options.
So I can obtain the goal of a 1.5 volt LDO by using 1 surface mount and 1 pinned Jfet or I can move the goal and use 2 cells.