rokuez
New Member
I have an understanding problem with diodes, and current.
I understand that silicon diodes are doped to give part of them P & N.
The P sections having more holes, and being called an anode.
The N sections having more electrons and being called a cathode.
I understand that diodes are not like on/off single pole single throw switches and that they have a exponential V I curve.
part 1
What I don't understand is why a forward based diode allows current to flow?
The reason why I'm not fully understanding this is because you have the positive terminal of the voltage source/battery connected to the anode (P with more holes) & the negative terminal of the voltage source/battery connected to the cathode (N with more electrons in the silicon substance)....
So doesn't the cathode in some sense repel electrons, sense it has more electrons in the silicon?
& likewise wouldn't the anode repel the conventional current flow from the positive terminal
Or at least for a split second, an initial moment, shouldn't this slight and immediate resistance to like forces be happening right before the larger battery voltage eventually overcomes the initial resistance so to speak of the doped N cathode having more electrons in the silicon and having electrons flowing towards the cathode from the negative terminal of the battery?
I do understand that like charges repel, and unlike electrical charge attract so in some sense I do understand how it works. I guess it makes sense to me because I think about when the voltage coming from both directions so to speak meets in the middle of the diode then current flows... But I just think for the first couple of electrons encountering the cathode they would be repelled, maybe for a slight instant??
part 2
also i'm a bit confused about a reversed biased diodes, for pretty much the same reason. the electrons are going towards the anode , which has "holes" i.e more positive charge? Likewise the cathode the silicon section with more electrons having it connected to the positive terminal of the battery shouldn't that attract the conventional current flow...?
I guess in summary I see the foward bias going like positive battery terminal to positive diode silicon part, and then negative battery terminal going to a negative cathode. I guess overall because greater potential difference/voltage pressure of the battery the charge flows through the diodes it makes sense...
But then I think about the reverse bias, and I think well why isn't the anode when facing the negative battery terminal causing some attraction & likewise the cathode facing the positive battery terminal causing some attraction thus allowing current to flow....
I understand that silicon diodes are doped to give part of them P & N.
The P sections having more holes, and being called an anode.
The N sections having more electrons and being called a cathode.
I understand that diodes are not like on/off single pole single throw switches and that they have a exponential V I curve.
part 1
What I don't understand is why a forward based diode allows current to flow?
The reason why I'm not fully understanding this is because you have the positive terminal of the voltage source/battery connected to the anode (P with more holes) & the negative terminal of the voltage source/battery connected to the cathode (N with more electrons in the silicon substance)....
So doesn't the cathode in some sense repel electrons, sense it has more electrons in the silicon?
& likewise wouldn't the anode repel the conventional current flow from the positive terminal
Or at least for a split second, an initial moment, shouldn't this slight and immediate resistance to like forces be happening right before the larger battery voltage eventually overcomes the initial resistance so to speak of the doped N cathode having more electrons in the silicon and having electrons flowing towards the cathode from the negative terminal of the battery?
I do understand that like charges repel, and unlike electrical charge attract so in some sense I do understand how it works. I guess it makes sense to me because I think about when the voltage coming from both directions so to speak meets in the middle of the diode then current flows... But I just think for the first couple of electrons encountering the cathode they would be repelled, maybe for a slight instant??
part 2
also i'm a bit confused about a reversed biased diodes, for pretty much the same reason. the electrons are going towards the anode , which has "holes" i.e more positive charge? Likewise the cathode the silicon section with more electrons having it connected to the positive terminal of the battery shouldn't that attract the conventional current flow...?
I guess in summary I see the foward bias going like positive battery terminal to positive diode silicon part, and then negative battery terminal going to a negative cathode. I guess overall because greater potential difference/voltage pressure of the battery the charge flows through the diodes it makes sense...
But then I think about the reverse bias, and I think well why isn't the anode when facing the negative battery terminal causing some attraction & likewise the cathode facing the positive battery terminal causing some attraction thus allowing current to flow....