What is the forward resistance of a diode?

Diode. When the forward conduction is on, its forward resistance r = (forward voltage drop v) (forward current i), where the forward voltage drop v is basically unchanged when the diode is forward conductive (silicon tube approx; Germanium tube about.

So, its forward resistance r is not constant, it is related to the magnitude of the forward current i.

Diodes are also known as crystal diodes, referred to as diodes, in addition, there are early vacuum electron diodes; It is an electronic device that conducts current in one direction. Inside the semiconductor diode there is a p-n junction.

Two lead terminals.

These electronic devices have the ability to transduce a unidirectional current in the direction of the applied voltage. Generally speaking, a crystal diode is a p-n junction interface formed by the sintering of p-type semiconductors and n-type semiconductors. A space charge layer is formed on both sides of its interface, which constitutes a self-built electric field.

When the applied voltage is equal to zero, due to the p-n junction carriers on both sides.

The diffusion current caused by the concentration difference and the drift current caused by the self-built electric field are equal and in an electrically balanced state, which is also a diode characteristic under normal conditions.

Point-contact diodes are high-frequency tubes, while surface-contact diodes are mostly low-frequency tubes. The test is carried out with a multimeter r 1k gear, and generally the forward resistance is less than 1k and most of the high-frequency tubes are used.

Silicon high-speed switching diodes have a large forward resistance. Measured with an R 1k resistor, the general forward resistance value is 5k 10k.

Fast recovery and ultra-fast recovery diodes are detected with R 1K resistors, and the general forward resistance is about 45K.

Put the multimeter in the R 1k gear, and measure the forward and reverse resistance values of the bidirectional trigger diode should be infinity.

For unipolar TVS, the forward resistance is generally about 4K.

For the bidirectional polar type TVS, the resistance value between the two pins should be infinity measured by arbitrarily changing the red and black watch pens, otherwise, the tube is not performing well or has been damaged.

When the multimeter is measured in the R 1k stop, the forward resistance of a normal high-frequency varistor diode is 5k 55k.

Place the multimeter in the R 1K stop and measure the forward and reverse resistance of the infrared light-emitting diode. Generally, the forward resistance should be about 30K, and the reverse resistance should be more than 500K, so that the tube can be used normally.

When the multimeter is placed in the R 1k stop (because the forward voltage drop of the laser diode is greater than that of a normal diode) to detect the forward resistance, the multimeter needle is only slightly deflected to the right, while the reverse resistance is infinite.

The diode is a semiconductor device, and the forward parameter is usually the on-voltage, which should not be expressed by resistance, because the number measured by the k and 10k gears of the multimeter is different.

First, the materials are different:1. The diode is generally made of semiconductor materials such as silicon and germanium with some impurity elements, and has unidirectional conductivity.

2. The resistor can be double-conducted, which is an energy-dissipating element.

2. Differences in voltammetry characteristics:1. The volt-ampere characteristic of the resistance is an oblique straight line.

2. The volt-ampere characteristics of the diode are approximately an inverse S-shaped curve.

3. Labeling differences:1. The circuit board labels the diode with D;

2. The resistor starts with R.

Diodes are generally made of semiconductor materials such as silicon and germanium with some impurity elements, and have unidirectional conductivity. The resistor can be double-conducted, which is an energy-dissipating element.

The two are completely different things, the diode is made of semiconductor materials, the resistor is generally made of carbon rods and the like, and the diode has the characteristics of unidirectional conduction.

A diode can only allow current to pass through in one direction, and a resistor can allow current to pass through in both directions.

The diode allows current to pass through in one direction, which can convert AC to DC; The current in the resistor can be double-conducted

The two are completely different things, the diode is made of semiconductor material and has the characteristics of unidirectional conduction.

Resistors are devices that hinder the flow of current, which are energy-consuming components, mainly converting electrical energy into heat energy.

When the diode is forward conducted, its forward resistance r = (forward voltage drop v) (forward current i), where the forward voltage drop v is basically unchanged when the diode is forward conducted (silicon tube approx; Germanium tube about.

So, its forward resistance r is not constant, it is related to the magnitude of the forward current i.

Diodes are also called crystal diodes, referred to as diodes, in addition, there are early vacuum electron diodes; It is an electronic device that conducts current in one direction. Inside the semiconductor diode, there is a PN junction with two lead terminals, and this electronic device has the conductivity of unidirectional current according to the direction of the applied voltage. Generally speaking, a crystal diode is a p-n junction interface formed by the sintering of p-type semiconductors and n-type semiconductors.

A space charge layer is formed on both sides of its interface, which constitutes a self-built electric field. When the applied voltage is equal to zero, the diffusion current caused by the concentration difference between the carriers on both sides of the p-n junction and the drift current caused by the self-generated electric field are equal and in a state of electrical equilibrium, which is also a characteristic of the diode under normal conditions.

Generally, it is measured according to the characteristics of the diode, and it can also be measured with a multimeter resistance. The diode is a semiconductor device with unidirectional conductivity, which can be measured using a multimeter, and the main Jane Sui takes to check whether its unilateral conductivity is normal, so as to judge the quality of the diode.

Here's how:

1. Put the black watch pen plug on the multimeter in the public "com" jack, and the red watch pen in the "V" jack.

2. Turn the gear switch to "diode with buzzer" and press the power switch of the multimeter. When a "1" is displayed on the screen, the test can begin.

3. Contact the red watch pen with the positive pole of the diode, and contact the black watch pen with the negative pole, then the positive resistance value of the diode is displayed on the screen, which should be about 500 -700 under normal circumstances.

4. Swap two pens for reverse testing, because at this time, the starting symbol "1" is displayed on the screen, indicating that the reverse resistance value is "m". This situation indicates that the diode is good.

5. If the switching diode is tested forward and backward, the results are both "1" or "0", or the reverse test shows that it is not "1", etc., these situations indicate that the diode is broken and can no longer be used.

The forward resistor is a diode.

The sum of the body resistance and the junction resistance, where the body resistance is less than the junction resistance, then you can think of the resistance of the positive potato grinding resistance as the junction resistance when the diode is forward conducting the high bucket, at this time the external field overcomes the internal field, promotes the movement of the multi-sub, and the current formed is large, we believe that its resistance value is small, and it is generally related to the q value of the diode.

The reverse resistance is actually a junction resistance, and its value is very large, because when the voltage is reversed, the internal field strength is large, which hinders the movement of many sons, and only the few tons form a small amount of current. Therefore, it is considered that the value of its reverse resistance is large. But this resistance is the inner field to block the current, if your backpressure is too big, the inner field is too strong, the inner field will break the covalent bonds in the crystal.

The electron overflow will make the current very large, which is its dynamic resistance can be considered small. The main anti-bias is the hand avalanche and Zener.

The forward resistance of the germanium diode is about 1000 and the reverse resistance is about 300.

The role of diodes includes rectifier circuits, detection circuits, voltage stabilization circuits, and various modulation circuits, which are mainly composed of diodes.

The birth of the colorful world of electronic information.

Use a multimeter to hit the cavity mu resistance level, measure the reverse resistance, if it is very small, it means that the diode is bad, if the reverse resistance is very large, it means that the diode is good.

For such basic components, we should firmly grasp the principle of its action and the basic circuit, so as to lay a good foundation for the future study of electronic technology.

The forward resistance of the diode is in the range of a few hundred ohms to several thousand ohms. Forward resistance refers to the resistance of electrons to flow when the diode is forward biased. A diode is a semiconductor component whose special electrical properties make it suitable for a variety of applications, including rectifier circuits, switching chain chain circuits, and signal amplification circuits.

Forward resistance is a very important parameter in these applications. The lower the forward resistance, the greater the current when the diode is turned on.

It is important to note that the forward resistance is not a fixed value. It depends on factors such as the diode's material, form, size, and operating conditions. Diodes made of different materials have different forward resistance characteristics.

For example, diodes made of silicon typically have a higher forward resistance than diodes made of germanium. In addition, different forms of diodes, such as Schottky diodes and Zener diodes, have different forward resistances.

In addition, the forward resistance of a diode is also affected by its operating conditions. For example, when the temperature of the diode rises, the value of the forward resistance will also change. This is because the increase in temperature causes a change in the conductivity of the semiconductor material, which affects the conductivity of the diode.

Therefore, factors such as the temperature coefficient of the diode need to be considered when designing the circuit.

In conclusion, the forward resistance of the diode is a very important parameter, which has an important impact on the working performance and application of the diode. It is necessary to select the right diode according to the specific operating conditions and materials, and use and design the circuit correctly in order to give full play to the performance of the diode. Minna <>