Why is the voltage drop of the diode different when it is turned on and when it is turned on?

The inside of the diode is a p-n junction, when the p-n junction is just energized, the electrons begin to move, forming an internal electric field, and the internal electric field force generated is in the opposite direction to the external electric field force, when the internal electric field force and the external electric field force reach equilibrium, the electrons will no longer move, and the internal electric field will no longer increase. When the diode is turned on, it acts like a wire.

After the diode is turned on, the electrical energy will be converted into heat energy in the flow of the diode to overcome the resistance of the chip vf.

The higher the current, the more heat energy is generated, the higher the temperature, and the VF changes.

However, after stopping the on-current, let the chip cool down to its original temperature for a period of time, and the vf can return to its original value.

The forward voltage drop of the diode is a certain function of the forward current, which is the volt-ampere characteristic of the diode.

The volt-ampere characteristic curve of the diode has a turn-on inflection point voltage, after which the current increases rapidly with the voltage, and this inflection point is called the diode's on-voltage.

If the temperature increases, the forward voltage drop decreases, which is the temperature characteristic of the diode.

For every forward voltage, there is a forward current. The current will heat up on the diode chip, resulting in a temperature rise, and the higher the current, the more obvious the temperature rise. As the temperature increases, the positive pressure drop decreases.

Depending on the flow current, the voltage drop will also vary slightly.

Diode on-voltage: After the diode is turned on forward, its forward voltage drop remains basically unchanged (silicon tube, germanium tube.

Under normal circumstances, the forward conduction voltage drop of the diode cannot be 0V. The diode is generally composed of two materials, silicon and germanium, the forward conduction voltage drop of silicon material diode is generally about about that, and the forward conduction voltage drop of germanium material diode is generally about about that, but it cannot be achieved at zero volts (ideal state).

Diodes are one of the earliest semiconductor devices and are used in a wide range of applications. In particular, in various electronic circuits, diodes are used to make appropriate connections with resistors, capacitors, inductors, and other components.

Circuits with different functions can realize a variety of functions such as AC rectification, modulation signal detection, limiting and clamping, and voltage regulation of power supply voltage. Diodes can be found in common radio circuits or in other household appliances or industrial control circuits.

Silicon material. The forward conduction voltage drop of diodes is generally about about that, and the forward conduction voltage drop of germanium diodes is generally about that, but it cannot be achieved at zero volts (ideal state).

If you are using a multimeter.

If the forward conduction voltage drop of the voltage measuring diode is 0V, it is possible that the diode has broken down, or the rear end of the diode is completely suspended (no current), or the diode is connected in parallel with other circuits with little to no voltage drop.

The diode has other circuits in parallel. When the diodes on the board are connected to other components in parallel, it is possible to measure the macro forward conduction voltage drop directly on the board to be 0V.

Conduction voltage drop: The electrical voltage corresponding to the diode when it starts to be conducted.

Forward characteristics: When the forward voltage is applied to the diode, the forward voltage is small at the beginning of the forward characteristic, which is not enough to overcome the blocking effect of the electric field in the PN junction, and the forward current is almost zero. When the forward voltage is large enough to overcome the PN junction electric field, the diode conducts hail and the current rises rapidly as the voltage increases.

Reverse characteristic: When the applied reverse voltage does not exceed a certain range, the current through the diode is the reverse current formed by the drifting motion of several carriers of the low-source type. Since the reverse current is small, the diode is in a cut-off state.

When the reverse voltage increases to a certain extent, the diode reverses through breakdown.

Summary. All correct, look at the circuit formed. In the comparison of bipolar transistors, generally speaking, the small voltage drop will be preferentially turned on, but when analyzing the common cathode and anode connection, it is the pilot with a large voltage drop, because in this case, it is from the upstream polarity to the downstream polarity, so the pilot with a large voltage drop will flow along the large pressure drop in the middle, which is also reasonable.

Is it easier to turn on the larger the voltage drop, why do some say that when the two diodes are compared together, the on-voltage is small and the on-voltage is preferentially turned on, but when analyzing the common cathode and anode connection, it is the pilot with a large voltage drop

are losing lead exactly, depending on the formation of the circuit. In the bipolar comparison, generally speaking, the first good to reduce the pressure pin will give priority to the ridge pass, but when analyzing the common cathode and anode connection, it is the pilot with a large pressure drop, because in this case, it is from the upstream polarity to the downstream polarity, so the pilot with a large pressure drop will flow along the large pressure drop in the middle, which is also reasonable.

You see if I say that, do you understand?

Then let me ask you, does the common yin and common yang refer to the parallel connection of diodes?

Yes, Xinfan, common yin and common yang refer to parallel diodes, and Natan bend common yin refers to two diodes with the same polarity in parallel; Whereas, common anodium refers to two diodes that are connected in parallel with opposite polarities.

Then this parallel relationship is not there these two, I really don't understand how to do it, my understanding is that the popular kind of sure voltage drop is smaller and easier to conduct, and you see that when the common yang and the common yin, the voltage of one section of it is the same, and the difference between the other section and this end is the smaller and smaller, the easier it is to complete the conduction, I understand the difference.

Your understanding is correct. In the common yin and common yang connection method, the smaller the voltage drop, the easier it is to turn on, and the voltage of one section is the same, the difference between the other section will inevitably become smaller, so that it is easier to complete the conduction. Jeongju Hu.

I understand what you mean, you mean that the greater the pressure drop, the faster the flow rate, but it doesn't make sense to combine it with the popular understanding of its preferential conduction.

Dear, combined with the above statement, are all correct.

Do you see anything else you don't understand?

At present, I can't understand this one, so since you said that when you are in the total yin and yang, you are looking at whose pressure drop is large and who is preferred, then under what circumstances is regret to see whose pressure is small, who is the priority of Bi Gaoqin?

When two diodes are connected in parallel, to see whose voltage drop is smaller, who has priority is to compare the on-voltage of the two diodes, and the small voltage drop will be preferentially turned on.

Then I just said that the common yin and yang is the parallel connection of the diode, is it possible that the common yin and yang is still a special parallel connection method? So what's so special about it?

The special feature of Chuntan is that two polarities and opposite pole roller tubes are connected in parallel, and the voltage of one section will be higher than that of the other section, so that the section with a large voltage drop will be preferentially turned on.

Let me ask again, do you see my understanding is correct, the voltage rise and the voltage drop are relative, if the voltage rise is small, then the voltage drop must be large.

It's a drop, it's a drop.

The diode on-voltage is that after the diode is turned on forward, its forward voltage drop remains basically unchanged. Forward CharacteristicsIn electronic circuits, the positive pole of the diode is connected to the high potential end and the negative terminal is connected to the low potential end, and the diode will be turned on, and this connection method is called forward bias. It must be noted that when the forward voltage applied to both ends of the diode is very small, the diode still cannot be conducted, and the forward current flowing through the diode is very weak.

Characteristics of the diodeThe biggest characteristic of diodes is that they are unidirectional, so they are widely used in rectifier circuits, switching circuits, protection circuits, etc. The so-called unidirectional conductivity means that when the reverse voltage is connected to both ends of the pn junction of the diode, the diode is cut off, and the diode can be turned on when a certain value of forward voltage is connected to both ends of the pn junction. This certain value of forward voltage is the forward conduction voltage drop of the diode.

In college, the diode conduction voltage drop is often identified, but in fact, the forward conduction voltage drop of the diode is not fixed, but is related to the current and ambient temperature flowing through the diode.