22 LED LEDs in parallel What is the current?

22 in parallel.

It is 420mA, and if you don't do enough power, you have to do about 350mA, and if you add the output of the voltage regulator, it is only 100mA, which means the rated voltage of this LED.

Exceeded, it is recommended that you do not need a voltage regulator, and after all the lights are combined, string a 1W resistor, your 100mA is the current of all the lamps combined, and the LED brightness of 100mA does not play out.

It's not this and it's not like this, there is always a difference in the voltage of different LEDs, at least the same color can be combined, otherwise the lower voltage of the current will definitely exceed the rated value of the first bad, the remaining current will be shared by the non-bad, soon all extinguished, as for the current is on, that is, the total current is too small, the LED is not working at full load, and the light is not the brightest.

Also, the voltage stabilization to, this is a redundant move, this is the normal luminous voltage range of the LED, you use the multimeter string here to measure the current is small, that is because the meter resistance is also about 1 ohm, should be measured in the battery, besides, the lithium battery voltage is in, is suspended, and it will drop in a few minutes, which has exceeded the LED working voltage, isn't it good? The working voltage is the same and then stringed together with a resistor current limit, and the current can be measured and converted by the voltage on the resistor.

The current of each is nominally a maximum of 25mA, but in fact it is generally better to use 15-18mA, and the total current of 22 is between 330-396mA.

A resistor that connects one in series.

Because the light-emitting tube has a partial voltage of 2V, the remaining 22V voltage is all borne by this resistor, and the current flowing through the light-emitting tube is designed to be 5mA (for insurance purposes), so the required resistance value is, because there is no such nominal resistance value, so it is taken.

The power is 22Vx5mA = 110MW, and it can be taken, but in order to keep the resistor from heating.

It is advisable to take it as appropriate.

To add to the note, the brightness of LED lights is not to look at the voltage but to see the current, the small power is generally about 20 milliamps, and the high power is divided into one watt and three watts. One watt is about 350 milliamps, and three watts are about 750 milliamps. The higher the power, the brighter the lights.

Emitting different colors of light has an impact on the power, current and voltage of the lamp beads. But the voltage judged by the color is only a range (more affected by the model), and the following is a brief description of the voltage of several colors.

<> only know that these lamps can not be wasted, only rely on the mouth to say no, mainly learn to do it yourself, according to the characteristics of the material, some lamp beads can not be disassembled according to the original plate transformation, some detachable on the disassembly and modification into other forms. The red working voltage, green, white, and blue working voltages are, and the working current is generally power LED (the kind used for lighting), and the working voltage is 350mA.

LED lamps are not the same due to the different materials doped with internal semiconductors, so that the light emitting color of the LED is different, and the current through the pn junction of the diode is also different, so that the voltage drop that each light emitting diode can bear is also different. There are also differences in the voltage of a specific lamp bead, such as a certain LED lamp bead, the nominal electrical pressure is. You don't want to drive voltage, the drive circuit must be constant.

The constant current drive circuit is designed according to the working current provided by the manufacturer.

If it is a lantern, the most used are three colors, red, green and blue. The on-voltage drop of the red LED is about 2V, and the green and blue are both 3. If the voltage of a diode reaches the normal luminous brightness, then when the voltage continues to rise to the brightness of the naked eye, it will be found that the voltage at the two ends of the diode can become, but the current measurement will find that it will increase a lot, and the tube will begin to heat up severely.

Such a diode can probably reach a state of 300 volts to 500 volts, and it is particularly bright, and it can also play an energy-saving effect, and the speed of operation is not very fast, I think it is really perfect.

Household LED lights are volts for each small light-emitting diode. Household LED lights are very energy-efficient, many homes will use LED lights, and it is very bright.

Green and yellow ordinary light-emitting diodes, their terminal voltage is about 2V, and in recent years, the emerging ultra-bright diodes, the working voltage is about 3V, such as green volts, blue volts, and white are essentially composed of blue light-emitting diodes and yellow filter materials, that is to say, their internal is also blue light-emitting diodes, and their working voltage is also volts.

The landlord has already said that the 380 LED light-emitting diodes in his hand are 3V, 20MA, what else to ask?

As for how much V is selected for the power supply voltage, it depends on how the landlord connects the 380 LEDs.

If 380 are connected in parallel:

The voltage needs to be 3V; The current needs 20mA 380=7600mA=.

If it's 2 in series, then in parallel:

The voltage needs to be 3V 2=6V; The current requires 20mA (380 2) = 3800mA =.

If it's 3 in series, then in parallel:

The voltage needs to be 3V 3=9V; The current requires 20mA (380 3).

If it's 4 in series, then in parallel:

The voltage needs to be 3V 4=12V; The current requires 20mA (380 4) = 1900mA =.

。If 380 are concatenated together:

The power supply voltage needs to be 3V 380=1140V; The current needs 20mA.

Additional answer: The power supply in the hand is; 48v、。

The current is too small to drive the LED to emit light.

Only 48V power can be used.

From the point of view of current, the number of parallels that can be connected at the same time is: 1800 20 = 90 (pcs);

From the perspective of voltage, the number of series connections that can be connected at the same time is: 48 3 = 16 (pcs).

From the point of view of power, the number that can be driven at the same time is: 48 1800 3 20 = 1440 (pcs).

The landlord has a total of 380 LEDs, which can be divided into 380 groups, 190 groups, 95 groups, 76 groups, 38 groups, 10 groups, 5 groups, 4 groups, 2 groups, and 1 group.

According to the number of series and parallel connections calculated above, the following connection methods can only be taken for hugging:

10 groups in series, and then 38 groups in parallel.

The total current at this time is 20 38 = 760 mA 1800 mA;

The total voltage is 3 10 = 30v 48v.

The building is mainly equipped with current limiting resistors and voltage divider resistors.

Can't be sure, there are too many unknowns.

Currents from 1-1000mA are possible.

Need to add a circuit to drive...

For example: VCC=5V 1 working circuit 20mA Then I need to string a ( resistor, this is a lamp, we do this very simply, the resistance in the circuit is to limit the current through the circuit of the LED, to avoid the LED from burning out.

Let me give you another example, for example, VCC12V, how much resistance do I need to string 3 LEDs? ( , the other hundreds of us are together, and it's still very troublesome to do so.)

So drive dozens, or hundreds of LEDs, how do we do it, it's too troublesome to do one by one, we usually combine LEDs into a series of combinations, like the 4 strings and 25 and so on.

There are two requirements for the drive circuit of LED:

1.That is, the power supply voltage should be greater than the total voltage of the LED string.

2.The current through each string of LEDs cannot be greater than 20mA, and we usually make it a constant current.

In view of this, we usually use an LED driver IC, made into an inverter boost, constant current circuit, to drive multiple and multi-string LED strings, there are many IC models, but also support dimming, etc., but this is a bit troublesome, if you want simple, use the method of string resistance, if you are not afraid of trouble, want to play, you can try, there is a lot of information on the Internet. Can hi me.

LED lamp beads are generally about 3V, and 4 lamp beads in series can reach 12V.

100 lamp beads are 4 strings of 25 and.

Do you understand?

Answer: Hello dear: The forward voltage of the light-emitting diode is generally more than 1V, and the current is generally 2mA. Therefore, when connected to a voltage of 12V, a resistor must be connected in series. The magnitude of the resistance can be calculated as follows: r = (12—1) ohms, i.e.

The working current of different light-emitting diodes is different, generally not more than 30mA (take a small point of light and dark but long life, not easy to break), if calculated by 30mA, i total current = 20 30mA = 600mA =

The total resistance of the circuit r=u i=12V The power dissipated by the resistor p=u i=(

Where is the estimated value, which is the voltage drop of an ordinary light-emitting diode, (a slight error has little effect on the calculation of the dissipated power, but it cannot be used to calculate the resistance of the string resistor).

Because you don't know the other parameters of the light-emitting diode, you can use a watt adjustable resistor string a w of fixed value resistance, and then string an ammeter and the light-emitting diode, the power supply is connected, adjust the adjustable resistance (from large to small), observe the ammeter to make the gauge hand indicate that the diode is normal to emit light at this time) and then shut down, measure the total resistance value of 50 adjustable resistance and 10 fixed value resistance, that is, the resistance value you need to string, find the same value, the resistance dissipation power greater than 6w can be connected to the circuit. (This method is the most accurate because of the large dispersion of transistor parameters).

Your Excellency asked the right person, each tube is connected with a 1,000-ohm resistor in series and then connected to a 12-volt power supply.

From a technical point of view: under the premise of requiring normal luminescence, how much voltage is needed for a single connection, how much voltage is needed for parallel connection.

In series, the number of single voltages can be used.

The key is in the control of the current.

However, now many drive power supplies, is constant current, the voltage can be automatically adjusted to the best state, according to the calculation of each LED 3V, 5 is 15V, 20 is 60V, but I have used the same driver to bring 2 beads - 20 beads (F5, that is, 5 mm lamp beads) can be used normally and for a long time, so the driver only needs to choose the appropriate current.

Direct paralleling, after a try, the resistance and power consumption are also large, and the parameters are determined.

The following data can be used as a reference. The formula for calculating the resistance.

Therefore, it should be the resistance of the string, if the parameters of each tube are slightly different, it may be that one tube has a large current and another current is very small or even not bright.

2) The resistance of a single tube string is connected to 12V, check the relevant information, according to the type of light-emitting diode, if is the general working current of LED. Still:

The normal voltage of each tube is multiplied by the number of tubes in a set. 6v. Build a circuit based on the estimated data.

The principle is that because the allowable range of current if is relatively wide, the most commonly used is 20 30mA, and then a series of current limiting resistors are connected to 12V, which is too wasteful of energy, and each group is strung into a series and then a current limiting resistor, that is, the voltage of the same tube is slightly higher or lower, and the current will vary greatly.

You can divide the 24 tubes into groups.

The voltage uf and current of each diode mentioned above are if, and the working current is from a few tenths of a milliampere to tens of milliamps, and uf is the forward voltage drop of the LED. This is because the current-limiting resistors should be serial separately.

As for a group of several and how large the string resistance is, it is best to connect several tubes in series. 4～3;if

where e is the supply voltage. Then according to the remaining voltage difference, n is the number of tubes in a group, depending on the model of the diode you bought, divided by the normal current:

The common light-emitting diode voltage is 1, so if there is no information, the voltage and current characteristics of the diode are similar to the characteristics of "voltage regulation" - the voltage changes little when the current of the same tube changes in a wide range, you can also try to come, if the brightness is not suitable, then change the resistance value, the current size determines the brightness. Conversely, it should be appropriately less than 12V. So, that's it.

Then connect each series in parallel to 12V:

r=（e－uf*n）/(1)

First of all, it should not be directly paralleled.

(1) First of all, it should not be directly paralleled, and the current-limiting resistors should be connected separately. This is because the voltage and current characteristics of diodes are similar to "voltage regulation" - the voltage does not change much when the current of the same tube changes over a wide range. Conversely, if the voltage of the same tube is slightly higher or lower, the current will vary greatly.

Therefore, if the parameters of each tube are slightly different, it is possible that one tube has a large current and another current is very small or even not bright.

2) The resistance of a single tube string is connected to 12V, which is too wasteful of energy and has a large resistance dissipation.

Therefore, it is best to connect several tubes in series, and then connect a current-limiting resistor to 12V.

You can divide the 24 tubes into groups and string each group into a string with a current-limiting resistor. Then connect each series in parallel to 12V, and you can do it.

As for the number of a group and the size of the string resistance, it should be determined according to the type and parameters of your light-emitting diode. The principles are:

The normal voltage of each tube is multiplied by the number of tubes in a group, and it should be appropriately less than 12V. According to the remaining voltage difference, divided by the normal current, it is the resistance that should be stringed. The formula for calculating the resistance.

r=（e－uf*n）/if

where e is the supply voltage, uf is the forward voltage drop of the LED, n is the number of tubes in a group, and if is the general working current of the LED.

The voltage UF and current IF of each diode mentioned above depend on the model of the diode you buy, check the relevant information. However, since the allowable range of current if is relatively wide, you can try it if you don't have any information. Build a circuit according to the estimated data, try it, and change the resistance value if the brightness is not suitable.

The following data can be used as a reference.

The common light-emitting diode voltage is between, the working current is from a few tenths of a milliampere to tens of milliamps, the most commonly used is 20 30mA, and the current size determines the brightness.