i read many things on net but still don't get it
i know it resists change in current
can you show me examples that i can see in real life?
when i apply voltage the core just gets magnet, thts all , with a potentiometer it makes no change in led light ! (connected in the way, if i connect it in parallel it short circuits!)
and as i heard it stores energy, i tried in both parallel and series, the led instantly turns off :!
It doesn't store energy for very long in "human terms", but you can see the effects in filter circuits or with an oscilloscope, etc.
i know it resists change in current
can you show me examples that i can see in real life?
I suppose the easiest way to demonstrate this is by touching both coil contacts while a battery is connected. Disconnect the battery, but keep touching the coil... As the coil discharges, attempting to "hold" the current through this new-higher resistance of your body, the voltage will jump* and you'll probably feel a shock!
Now, I DO NOT RECOMMEND THAT YOU INTENTIONALLY GIVE YOURSELF OR ANYONE ELSE AN ELECTRICAL SHOCK, but an accidental shock from a coil is a reminder of what coils/inductors can do.
Or if you see a spark when you disconnect the battery, that's an indication of higher than "battery voltage" as the coil "tries to keep the current flowing" when there is no connection.
This is basically how a [u]spark plug coil[/u] in a car generates a high-voltage spark from a 12V battery. (Although, a spark plug coil is actually a transformer that further-boosts the "kick back voltage" when the distributor points break the connection.)
with a potentiometer it makes no change in led light
I'm not sure what you are dong with the pot, but due to the relatively high currents and low resistance of coils or solenoids, they are rarely used directly with pots (which are generally higher resistance and have lower power/current capabilities).
Could it be looked at like this? :
A capacitor is essentially an open circuit device (without the associated esr etc), charge is static and held.
An inductor is conductive in nature and thus the charge is dynamic and dissipated trying to maintain the magnetic field.
Just rambling on here!
Could it be looked at like this? :
A capacitor is essentially an open circuit device (without the associated esr etc), charge is static and held.
An inductor is conductive in nature and thus the charge is dynamic and dissipated trying to maintain the magnetic field.
Just off the top of my head.... A capacitor with no connection can hold a charge for a long time because there is essentially no current. The ESR (effective series resistance) isn't an issue, but the parallel leakage resistance is related to self-discharge.
I think for an inductor to "hold a charge" for a long time, you need the opposite... Zero resistance, so the current can flow with no voltage drop and no power loss.
It doesn't really make sense to say this: But, it's like a capacitor's internal leakage resistance "nearly infinity", but an in inductor's resistance is not so close to zero.
I think those super-cooled superconductor demonstrations are somehow related to this.
The inductor simply converts electrical power into electromagnetic power...
When the inductor is powered, a magnetic field is produced, so it's energy is converted
The magic happens when the current ceases, the MF collapses and when this happens voltage and current is produced in an opposite way.
However an inductor can produce voltages much higher than you supplied to it to begin with breaking sensitive electronics.
DVDdoug:
Just off the top of my head.... A capacitor with no connection can hold a charge for a long time because there is essentially no current. The ESR (effective series resistance) isn't an issue, but the parallel leakage resistance is related to self-discharge.I think for an inductor to "hold a charge" for a long time, you need the opposite... Zero resistance, so the current can flow with no voltage drop and no power loss.
It doesn't really make sense to say this: But, it's like a capacitor's internal leakage resistance "nearly infinity", but an in inductor's resistance is not so close to zero.
I think those super-cooled superconductor demonstrations are somehow related to this.
Soo, I get what you mean about the resistance, makes sense.
Defines the same statement from another perspective too?
The equation for a theoretically perfect inductor can be expressed
as "rate of change of current is directly proportional to voltage". Which
means that if you try to reduce the current suddenly a large voltage will
be generated to oppose that rapid change. You can also think of it
as if the charge carriers in the coil have extra "momentum" - it takes effort
to get them moving, and they will do damage if you try to stop them
suddenly.
By contrast a resistor only requires work while the current is flowing, not
to change the current.
Magnetic fields store energy at a density proportional to the square of
the field strength, and that itself depends on the current, so the energy
stored is proportional to the square of the current - in fact its 1/2 L I^2
The best way to see the "resist change in current" is to get a stationary bike with a generator. Put lower resistance loads on the generator and it gets harder to pedal.
wow, i just slept and found out a full page of answers next day xD thanks a lot 
i now understand what inductor does (i wish i posted here sooner)
and now i can guess how a boost works ! by constantly applying and disconnecting a voltage to induct or (i assume 
)
anyway. can you also tell me a few example's of devices(or circuits) that use this? also i now PSU has lots of this what exactly do they need it for?
with the coil i made myself there was no shock at all ! only spark on alligator connectors , and the inductor gets warm !!!
but yesterday i was making speaker with relay and i experienced some hard shocks well i didn't know it back than
i made the this Circuit but without the capacitor
and i opened ans closed the switch with mosfet and controlled the mosfet with arduino (on and off with diffrent delay and no delay) none worked ! it only made it lower, but when i lowered the delay, the voltage increased! 1.5v from 1.2v the battery i connected is 9v
is this beacause the speed is slow?
when i connected capacitor my multimeter read 0
(i used relay instead of inductor )
With inductors and capacitors you don't even notice them in the circuit as long as voltage is constant. An inductor will appear as a short circuit and a capacitor will appear as an open circuit.
If you give them an alternating current, however, as you increase the frequency, the capacitor will appear to conduct more, while the inductor appears to conducts less.
cjdelphi:
The magic happens when the current ceases, the MF collapses and when this happens voltage and current is produced in an opposite way.
I wish people would not say things like this! It hinders rather than helps.
The current is not "produced in an opposite way". It is critical to understand that the effect of the inductance is to cause the current to keep flowing in the original direction.
Hi, try this link.
Tom.....
TomGeorge:
Hi, try this link.Inductor basics – What is an inductor? | Afrotechmods - Fun with electronics!
Tom.....
thanks but i can't watch videos in my stupid country........ its basically hell_on_earth^2
but the first answer mostly gave me an good idea about instructors !
i guess they should use it on PSU to avoid giving less current to computer parts !
btw, anyone can tell me why my own designed boost didn't work? low frequency? or ....
instructors sound fun to play with
Paul__B:
I wish people would not say things like this! It hinders rather than helps.The current is not "produced in an opposite way". It is critical to understand that the effect of the inductance is to cause the current to keep flowing in the original direction.
i see, i was about to ask why then do some circuits i saw on net work !
Paul__B:
I wish people would not say things like this! It hinders rather than helps.The current is not "produced in an opposite way". It is critical to understand that the effect of the inductance is to cause the current to keep flowing in the original direction.
Well, I'm not sure why I was thinking what I was, too much beer I suspect, in my head I was confusing the effect of transformer and the induced currents into the secondary coil..
Take this circuit I've attached, from 5v to 100v
cjdelphi:
Inductors are cool
They're like resistors but with curves. Hmmm nice
cjdelphi:
Inductors are cool
whats that software/thing ? and thanks, let me see if i can make it:( i don't think i can find the parts
