how does a diode work?

Question

i tried to understand how a diode works but i just cant seem to grasp the information maybe if you could make it easier to understand i could get it plz help me.

Answer 1

The fluid analogy shown here:

http://en.wikipedia.org/wiki/Diode#Hydrodynamic_analogy

may help. The fluid pushes against the ball, and if it asserts enough pressure, it compresses the spring and moves the ball out of the way so that fluid can flow. Alternatively, if fluid tries to push the other way on the ball, it just keeps the opening closed. Of course, if it pushes too hard, it will destroy the opening, which is similar to the reverse breakdown of a diode.

Now let's consider a real diode. You have an n-type material and a p-type material. Both materials are NEUTRAL and have a crystal lattice structure. However, the p-type material has locations where an atom has TOO FEW electrons to bond to all of the atoms around it. That means that it has extra "holes." Similarly, the n-type material has locations where an atom has TOO MANY electrons to bond to the atoms around it, so it has extra "electrons."

Now jam p-type material right next to n-type material. The extra holes will diffuse (like gas from a gas leak) from the NEUTRAL p-type material into the NEUTRAL n-type material. Similarly, the extra electrons will diffuse from the NEUTRAL n-type material into the NEUTRAL p-type material. While the combination of the two materials is still collectively NEURAL, the BALANCE of charges has been messed up, so that now the p-type material is too negative and the n-type material is too positive. This charge imbalance (like a dipole) will start to slow down diffusion. That is, holes will want to stay in their NEGATIVE material and electrons will want to stay in their POSITIVE material.

Now, imagine you hook up a battery so that its negative (-) end is connected to the n-type material and its positive (+) end is connected to the p-type material. Remember that the p-type material has EXTRA electrons *AND* electrons from the n-type material have STOPPED moving into the p-type material because of it. NEW electrons from the battery's NEGATIVE end are present at the n-type material. Those electrons have a slightly UPHILL battle to go from the n-type material to the p-type material because of the charge imbalance between the n and p type materials. If they have enough energy, they'll start flowing. Otherwise, no current will flow.

Similarly, if we hook the battery up the OTHER way (negative electrons connected to "negatively charged" p-type material), the electrons from the battery will have no reason to enter the p-type material because of all of the electrons already there. So, current will never flow this way (unless so much voltage is present that the device breaks down (i.e., fries)).

So, the fluid analogy really works well. Electric current must have enough energy to get over a small barrier in order to flow in ONE DIRECTION through the device. Otherwise, current will never flow.

Answer 2

How Does A Diode Work

Answer 3

A diode symbol looks like an arrow

Current comes out of the bar end (the sharp end)
if you put positive volts on the blunt end

It gets the anode and cathode naming from the triode valve
(current in the triode flows the same way from anode to kathode)

A diode has a logarithmic response, a 18 mv change cause a doubling of current

It has a negative temp coeff -2 mV / deg C

The leakage current doubles for every 10 deg C

A zener diode is a good noise source

A schottky diode drops half the voltage but they
get expensive with more than 30 Vr

You choose a diode according to forward current (peak repetitive or continuous) forward volts, reverse volts, leakage current


What else do you want to know about a diode?

You can learn the parameters ....but the above info is what you design with ....kinda makes college work redundant

Answer 4

This Site Might Help You.

RE:
how does a diode work?
i tried to understand how a diode works but i just cant seem to grasp the information maybe if you could make it easier to understand i could get it plz help me.

Answer 5

A simple diode consists of a P-N junction (P stands for positive-type material and N stands for negative-type material). What the manufacturers do is to take silicon crystals and "dope" it with other elements (boron and phosphorus, I think). This makes materials that have one more or one less electrons within the silicon crystal. When applying a voltage to the P-N junction, the electrons or holes (lack of electrons) migrate toward or away from the junction. By changing the voltage applied across the junction the conductance across the junction is changed.