colin mac said:I've long been confused by Lenz's law and I'm looking here trying to make sense of what is going on.
It explains that if you have an inductor and pot in series and the current is constant, there is no voltage dropped across the coil. That's fine. It then says
that if the resistance of the pot is reduced so to increase the current, a voltage
is induced in the coil. My first question on that is, does the voltage across the inductor plus the voltage across the resistor add up to more than the battery voltage then?
It then says that the polarity of the induced voltage is such that it tries to keep
the current constant. Does that mean if you started out with say 12V battery and 1K pot resistance and then reduced the resistance the current stays at 12mA? If so, would that mean the voltage across the resistor decreases? Could anyone explain please?
colin mac said:I think I understand. Does Lenz's law say that the magnetic flux produced by the current through the coil changes (gets bigger and smaller) so that when added to the magnetic flux from the moving magnet, the overall flux stays constant?
The current flowing from the battery thru the coil will increase exponentially until the coil/core saturates
No, its a first order differential relationship.
V = L*di/dt
I've always thought about inductors and capacitors as, "1's". The voltage across a 1F capacitor, charging at a rate of 1A, increases by 1V per second. The current through a 1H inductor, with 1V applied across it, will increase at a rate of 1A per second.
Unless I'm missing the whole point, that seems pretty linear.
hi,
Perhaps this link will help explain.
Googled for Inductor Current
I've always thought about inductors and capacitors as, "1's". The voltage across a 1F capacitor, charging at a rate of 1A, increases by 1V per second. The current through a 1H inductor, with 1V applied across it, will increase at a rate of 1A per second.
Unless I'm missing the whole point, that seems pretty linear.
The voltages across inductors are measured all the time but, usually with an oscilloscope since they are changing at the time of measurement.
No, I didn't college in the UK. I have been to the UK a few times since I had a job that took me to various satellite tracking stations (including the one in Oakhanger...not the NATO stuff just down the road). I would usually stay in Alton. England is nice...especially if you get there during your two weeks of summer. My college "career" was at a 2 year junior college in Central Oregon.
The definition of a linear relationship is 2*f(x) = f(2*x).
hi,
Think of it in terms of 'magnetic fields'.
When a current is flowing in a coil a magnetic field is created around the coil.
Its like a electromagnet. **SNIP**
Wow, I'm not even sure where to start and stop quoting here.
**SNIP**
....thanks everyone for making my brain work!
My brain is wired different than most people who are here it seems. I have to pretty much brute-force my way through these /QUOTE]
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?