Can high voltage and low current burn LEDs

First of all, you are in series, some are bright and some are not bright, which means that there is no broken circuit, that is, some are short-circuited, you first check whether it is a short circuit.

This problem depends on how much the partial pressure of each small lamp is, and the partial pressure should not be too much of a problem.

But isn't the LED very bright, it's generally around 2MA, maybe your light is not the same as the one I use.

But generally do advertising lights, actually use tandem, you are very creative

If it doesn't light up for a few days, it won't be a short circuit, which means that some lamp resistance has changed, resulting in no light, which is the quality problem of the lamp.

You may not have given each LED in series with its own current-limiting resistor.

No. Sufficient heat is necessary to burn, and it can be seen from the heat formula q=i rt that the heat generated is related to the magnitude of the current, and only when the current is large can enough heat be generated.

High pressure to a certain extent, will burn the LED.

An LED is a diode, and its role is determined by an electric current.

However, if the voltage is too high and exceeds the maximum withstand voltage of the diode, the diode will burn out and the LED will be destroyed.

Yes, the point is that if you use a high voltage, you will generate a high current. You can only control one voltage and current, and it is impossible to control two at the same time.

LED chips are very sensitive to changes in voltage, PichaiA small deviation of the operating voltage will cause a large change in the currentAs can be seen from the volt-ampere characteristic curves of the two LED products in the figure below, the LED driver is the bestUse a constant current driveIf you use a regulated power supply to drive, you should use a high voltage stable power supply, if the stability is not good, it is very easy to burn the LED chip. Different degrees of deviation from the first voltage of LED electric rottennessIt should be according to the product manualThe rating givenThe operating current range controls the range of deviation of the voltage. Instead, the driver that should use a constant current source is the best choice, and try not to use a regulated power supply.

Burning indicates that the circuit current is too high. Generally, the standard current used in LEDs is 20mA, and depending on the performance of the wafer, it can be adjusted to about 60mA without burning out immediately, and about 80mA will cause LED burnout. The subject's LED is 3V voltage, which can be judged as dual-electrode white, blue or green light.

Although it is a nonlinear component, it still adheres to the volt-ampere characteristics, according to the title, the resistance of a 3V 1A circuit is 3 ohms, and in order to achieve a current of 3V, the resistance in the circuit should be 3 002=150 ohms, there is LED resistance in the circuit, but this resistance value will change with the use time and the heating of the LED, the higher the heat, the greater the LED current. At present, the general voltage of LED is about, and in order to use normally, the current needs to be further reduced to.

Therefore, according to the comprehensive calculation, at least a 10 ohm resistor should be installed in series with the LED.

The DC supply voltage is consistent with the voltage of the consumer, and the electrical appliance will not exceed the current, you can measure the actual voltage of the transformer rectifier filter, and the actual current of the lamp bead to confirm.

If you want to reduce the supply voltage, you can connect multiple diodes in series (1 diode step-down volt) in the forward direction.

Select a diode that is more than twice the current required for the lamp bead.

N diodes can be added to the back of the power module to step down in series. The diode series group and the lamp bead plate are used in series.

Yes, the rated voltage and current of LED lamps are about the same, except for high-power lamp beads.

Summary. There is no impact, LED is a wide voltage display, as long as the voltage is not high, it generally does not burn out.

Hello, I have seen your question, and I am sorting out the answer, please wait for a while There is no effect, LED is a wide voltage display, as long as the voltage is not high, it generally does not burn out.

Yes led wicks are always bad.

Is there a power adapter, install one.

We are a unit in the wick of the frequency of broken a bit high, the unit of the house is seven years old house.

You can buy a small voltage regulator, and fluctuations caused by the aging of the power supply are also possible. It's time to change the cables, it's a bit dangerous to use this way.

Can this general professional electrician repair it?

It's okay, the main thing is safety. There are too many high-powered appliances in winter.

There is heating equipment in the unit, and there is no imitation of high-power electrical appliances, how to say ......There are two hundred lamps in total, ......In the morning, 4 wicks were replaced, and in the afternoon, 3 wicks were broken in the room of the stove.

The live or neutral wire of the power supply is grounded.

There are ground wires, but the frequency of bad is increasing, and the general problem is that the probability of ** is high.

Many ground wires are fictitious, and yellow and green wires are not necessarily grounded. Is there an open-air line or is the line going to the roof?

Okay, thank you, wait until I get an electrician to check the ground wire.

It's not the ground wire, it's the live wire or the neutral wire.

The 470K resistance is too big, you can do the math, there is only one 470K resistor (no LED) in the 3V circuit in series, and its current is 3V 470K=; If it's not 470K (clerical error) but 470 ohms, the current is 6mA, which is too small for the LED to be lit.

Because LEDs are a current element, it is important to understand the current value given by the manufacturer before designing a circuit. Only when the current value of the LED is normal can the maximum output power and the longest life be guaranteed.

You can check the current value of the LED you are using, for example, 5050 chip is 20mA, 5630 is 120mA.

Using 5050 as an example, the following test is performed:

A 470 ohm variable resistor is used instead of a 470K fixed value resistor, which is connected in series with the LED to connect to 3V, and the loop current is monitored with an ammeter. Adjust the 470 ohm adjustable resistor to make the current reach 20mA, remove the voltage, measure the actual resistance of the adjustable resistor (it should be about ten digits), and replace it with an same fixed value of 1 8w resistor.

How your LEDs are different above can be determined by referring to the above experiments.

The pressure drop of the high-power light-emitting tube is left and right. Small light-emitting tubes left and right. If the voltage is below the threshold, it will not turn on. The 47ok resistance is too large, the LED glows slightly, and the life will be very long.

LED will break when working at a high voltage of 3 volts for a long time, and if a 470k resistor is added, the current will become smaller and darker. But the voltage is still volt, LED is no problem at all, but it loses the meaning of using LED.

The correct way is to refer to the LED data sheet to see what its rated operating current is, and then determine the current limiting resistance value based on the input voltage and the LED on-voltage drop. r=(

Is your resistor string or merging?

But depending on your results, it should be combined, a string of 470k, how much of a voltage drop, after the string, if the power is not large enough, it will burn off immediately.

In order to provide the voltage to the lamp bead, the resistance of the string also needs to be calculated by the driving current of the lamp bead.

If the voltage is too low, the LED is dim and does not work properly; Too high a voltage can lead to a shorter life of LED equipment or even burnout.

Light-emitting diodes.

Abbreviated as LED. It is made of compounds containing gallium (Ga), arsenic (As), phosphorus (P), nitrogen (N), etc.

Principle. It is.

Semiconductor diodes.

can convert electrical energy into light energy. Light emitting diodes with.

Ordinary diodes.

The same is made up of one.

PN knots. composition, also has a good old hole.

Unidirectional conductivity.

When a forward voltage is applied to the light-emitting diode, the electrons injected from the p-region to the n-region and from the n-region to the p-region are recombined with the n-region electrons and the p-region holes within a few microns near the p-n junction to produce electrons.

Spontaneous radiation. of fluorescence. Distinct.

Semiconductor materials.

Middle. Electrons and holes.

The energy states they are in are different. The amount of energy released when electrons and holes recombine is somewhat different, and the more energy released, the shorter the wavelength of the light emitted. Commonly used is red, green, or .

Yellow. diodes. Characteristic. And.

Incandescent bulbs. And.

Neon lamp. In contrast, the characteristics of the light-emitting diode friend dry tube are:

The operating voltage is very low (some are only a few volts);

The working current is very small (some can emit light only a few tenths of a milliampere);

Good impact and seismic resistance, high reliability and long life;

The intensity of the luminous light can be easily modulated by modulating the strength of the passing current.

Due to these characteristics, light-emitting diodes are used as light sources in some photoelectric control devices and signal displays in many electronic devices.