meaning of henry

[PG1995]

Hi

It is easy to conceptualize meaning of one farad for a capacitor. If a capacitor is rated at 2 farad then that means it would take 2 coulombs of charge to for raise of every 1 volt. But I don't get the meaning of one henry for an inductor. One henry stands 1 volt per (ampere per second). What do it really mean? Please help me with it.

 

[MrAl]

Hi,

If you apply 1v across an inductance of 1H you get an increase in current of 1 amp every second. The current ramps up.

 

[dragonwarrior]

The inductance is given by the relation : magnetic flux linked( phi) =Inductance (L) * Current (I)
so,1 H means,The coil or wire attains a magnetic flux linkage of 1 Wb around it (Weber) when it accepts a current of 1 A ( Ampere).

 

[bountyhunter]

Hi

It is easy to conceptualize meaning of one farad for a capacitor. If a capacitor is rated at 2 farad then that means it would take 2 coulombs of charge to for raise of every 1 volt. But I don't get the meaning of one henry for an inductor. One henry stands 1 volt per (ampere per second). What do it really mean? Please help me with it.

A Henry (which is the unit of inductance) is defined by:

V = L (dI/dt)

It is a measure of how much the circuit element OPPOSES a change in current with respect to time.

If you use a power supply (voltage source) and switch and "snap" a voltage across an inductor, you can look at the rising current rate and calculate it's inductance by HOW FAST the current rises.

 

[cachehiker]

Inductance equates to inertia.

Water in a pipe is similar to current in an inductor.

Open the valve (apply a voltage) at one end and there is initally no current at the other as the pipe must first fill with flowing water which possesses kinetic energy which would be analogous to the energy stored in the magnetic field.

Close a theoretical valve at either end in zero seconds and the inertia of the water momentarily produces infinite negative pressure at one end or positive pressure at the other.

Of course it take a long pipe and lots of flow for these effects to be dramatic. A 10 foot long section under your sink would be like a wire on your board and neither valves nor transistors open and close in zero seconds. Try one hundred turns of 1" pipe around a large backyard, maintain 60 psi (Volt) input with little flow restriction (resistance), and see how quick it destroys a fast, solenoid operated valve rated for 200 psi at the other end.