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What else can I help you with?
How do you convert 12 volts dc to 3 volts dc for LED?
Depends on the led forward bias threashold, if its a typical led it will be .7 volts so, .7x6=4.2V, so pick a resistor that will drop around 7 volts. What is the current? Then just to V=IR, 7=IR.
Led circuit for 120 volts?
There can be no answer for this without knowing how strong a resistor is involved. (Ohms)
Why is a resistor used to operate an LED?
To calculate the current through an LED, use the following formula Current = (Source_voltage - Led_voltage_drop)/Resistance Now if you didn't use a resistor, the you only have the resistance in the wire, which is very small (eg .001 ohm). So if you have for instance a 9V battery, and a 2.1 volt drop across the LED, the resultant current would be so high, it would destroy the LED. We put a resistor in to lower the current to an acceptable range (often 20-30ma)
How do you light a 3 volt led light with a 6 volt battery?
To light a 3-volt LED with a 6-volt battery, you need to use a current-limiting resistor to prevent the LED from burning out due to excessive voltage. Calculate the resistor value using Ohm's Law: ( R = \frac{(V_{battery} - V_{LED})}{I} ), where ( V_{battery} ) is 6 volts, ( V_{LED} ) is 3 volts, and ( I ) is the desired current through the LED (usually around 20 mA for standard LEDs). Connect the resistor in series with the LED to ensure the correct voltage and current flow.
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.
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.
How is the brightness of the LED affected by different resistor values?
LED's are light emmitting diodes. diodes have a voltage threshold that must be reached for them to fully "turn on". A resistor can be used to limit that voltage. As the voltage drop across the diode is increased above the turn on voltage (typically .5 - .7 volts), the diode will emmit light. The LED will only light up so far, so by turning the voltage up significantly more will have a very limitted payback in light output.
If you interchange resistor and led what happens?
Nothing changes. The circuit operates as before. Just make sure that the orientation of the LED does not change.
What will happen when 3 1.5 volt batteries are connected to an LED?
When three 1.5-volt batteries are connected in series, they will provide a total voltage of 4.5 volts to the LED. If the LED's forward voltage rating is lower than 4.5 volts (typically around 2-3 volts for standard LEDs), it will illuminate brightly. However, if the voltage exceeds the LED's rating, it could lead to overheating and damage the LED. To ensure safe operation, a current-limiting resistor is often used in series with the LED.
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.
How can you make a LED light up on only one 1.2 volt battery?
A: WELL you cannot not with 1,2v most LED start emitting at 1.8 v some as high as 5 volts . two need at least two 1.2 volts better is 9 volts then there is a problem voltage wise but the problem is now that you need a limiting resistor to ensure at least 10ma of current
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.
