answersLogoWhite

0


Best Answer

Has nothing to do with the intensity of the LED, and all to do with the voltage/amperage of thediode, and the voltage of the system it is supposed to be used with.

User Avatar

Wiki User

14y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: How much resistor should use for 20000mcd led?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

Why do we put a resistor in series with an LED?

A correctly rated resistor will prevent that the LED is not burnt out if it receives too much power.


What side of the LED should the resistor be attached to?

It doesn't mater.


Using an LED and a nine volt battery what resistor should you use?

34Kohms


Why does a Led have a 470 resistor connected to the LED?

A: That resistor is there to limit the current to the LED it can be any value if the voltage is decreased or increased or no resistor if the voltage across the led is equal to the forward voltage drop.


Should a resistor go on the positive or negative side of an LED?

It does not matter. Kirchoff's Current Law states that the signed sum of the currents entering a node is zero. A consequence of that law is that the current in every part of a series circuit is the same. The only thing that resistor location affects is the potential voltage of the LED terminals with respect to the rest of the circuit. Certainly, if you are driving the LED with high voltage, such as 120VAC, you should consider the resistor location so as to reduce electrocution hazard but, the LED's performance is not affected by resistor location in the circuit.


How do you connect an LED into a circuit?

A: Add the proper resistor in series with the LED. What resistor? Simple 10volts source minus the LED source divided by the 20ma current that should be flowing gives you the resistor 10-1.8=8.2/.02=900 ohms. The 1.8 can be anything it is up to the LED voltage drop. LONG LEAD IS POSITIVE SHORT IS NEGATIVE SINCE IT IS A DIODE


Why must an LED always have a resistor connected in series with it?

An LED usually has a resistor connected in series with it because an LED (light emitting diode) is not linear in current to voltage (like a resistor) and has to be operated within specified current and voltage conditions. In most circuits the supply voltage is higher than the forward voltage of the LED so the LED would burn up from too much current without a current limiting resistor in series. The resistor sets the voltage and current to a good operating point (voltage and current) for the LED by dropping some voltage across it. The operating point varies depending on the size, type and manufacturer of an LED so the LED's data is used to select the right resistor size for a given voltage source.


Why you use resistor with variable resistor?

Often we want to easily change a resistor value, so we use a variable resistor. For example, we may want to change the resistor that controls the power sent to a LED, so we can easily make it brighter or dimmer. Often if we use a variable resistor, there is only a very narrow range that is useful. Continuing our example, sometimes we use several LEDs, and we use the variable resistor to set them all to the same brightness. In this case, the resistance range that sets the LED to be twice as bright as the the other LEDs, and the resistance range that sends so much power to the LED that it is permanently destroyed is even less useful. So we add a fixed resistor in series with the variable resistor -- the fixed resistor sets the minimum net resistance, no matter how we turn the knob on the variable resistor. In our example, the addition of the fixed resistor allows us to turn the variable resistor throughout its whole range, and the LED gets brighter and dimmer; without that resistor, a certain range of the knob on the variable resistor would allow so much power to go to the LED that it would be destroyed.


What side of the LED should the resistor be attached to lower the 12 volts DC to the LCD?

I'm pretty sure it doen't matter, the total resistance of the circuit is what counts, the diagrams I have seen however predominantly put the resistor on the + (anode) side of the LED.


What is a protective resistor?

The protecting resistor is put in series with the LED so that you have a voltage divider - the supply voltage is split across the LED ( max 0.6v) and the remainder across the protecting resistor. So if your supply is 6volts, 5.4v will be across the resistor,


What is my Led and what resistor do I need?

Led is a light emitting diodes which can two leads .one lead is larger and the other is smaller. You did't use any resistor because it glows with the small amount of energy! Idiot. I mean't how to I find out what my LED is. I know what a Led is and without a resistor, you prick, It wouldnt last a second.


What is the function of the resistor in an led circuit?

current limiter.