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How is the brightness of the LED affected by different resistor values?
Wiki User
∙ 14y ago
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.
Wiki User
∙ 14y ago
Wiki User
∙ 13y agoThe wattage rating of a resistor just tells you how many volts can be across the resistor times the current flowing through the resistor. If there is a resistor in series with the LED then the higher the resistance, the lower the brightness. A low wattage rated resistor would effectively limit the maximum current that could flow without the resistor self-destructing so in that sense a low wattage rating would also limit maximum brightness.
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How do you find unknown value of a resistor when total resistor values and voltage are known in a series circuit?
A: If you know the total resistance and total voltage then you know total current flow for the circuit, this current will be same for every resistor in series however the voltage drop will change for each resistor . So measuring the voltage drop across the resistor in question and divide by the total current will give you the resistor value.
Equation for Resistor serial and parallel?
In series, you just add the resistor values together to find the total resistance. In parallel you can use the following equation you can find the total resistance by multiplying the lowest and highest resistor value, the dividing that by the sum of all the resistor values you have in parallel. you could also take the inverse of all the inverses of you resistor values added together.
Are resistor heating affected by line frequency?
No. The heating effect is the product of the square of the current and resistance, where the current is a root-mean-square value.A.C. current is always expressed as a root-mean-square (r.m.s.) value, which is equivalent to a d.c. current which produces exactly the same heating effect. Root-mean-square values are affected by the shape of a waveform, but not by its frequency.
Why are fixed resisters used in many circuts?
Hi, where there is no need of changing the value of resistor then why do you place variable resistor instead a fixed resistor. After all the selection of resistor depends on the cause of use in application. by the way wide range of resistor values are avilable in the market. if the application requires tuning operation then variable resistor is need to be mounted. nothing is mandatory unless the application requires. Regards, Manjunath A.V
What are brightness and contrast in image processing?
Brightness and contrast represent a way to adjust an image. They come from the display technology, being common controls in all monitors. The color brightness/contrast are similar to the grayscale counterparts, in most cases being applied to all channels (even if from the physical point of view this is wrong - a transformation into HSI with adjustment of the I component would be correct -. For a grayscale image, brightness represents an image adjustment where a constant value is added to all pixel values. The contrast adjustament is a multiplication of the pixel values with a constant. Most of the image processing programs use a different scale, for example from 0 to 10. If you wish to experiment with it, you can do it photoshop, gimp. To apply a brightness/contrast correction to a bunch of images is easier with an image converter like AZImage - see related link.
How do you find unknown value of a resistor when total resistor values and voltage are known in a series circuit?
A: If you know the total resistance and total voltage then you know total current flow for the circuit, this current will be same for every resistor in series however the voltage drop will change for each resistor . So measuring the voltage drop across the resistor in question and divide by the total current will give you the resistor value.
What are resistor values defined by?
Resistor value is defined by the Resistance the resistor offers in Kilo ohms/ohms value given by color codes on the resistor.
What is negative perspective?
The brightness values of a camera are reversed.
What is type of resistor in edc labs?
those are the fixed resistor...u can't change their values..
What are the thermisters?
It's a resistor that changes values based on the temperature.
Is the mode affected by extremely low or high values?
No, extremely low or high values are affected by the mean.
Where are resistor decade boxes commonly used?
designing circuits by semi-trial and error selection of the right resistor values.
Equation for Resistor serial and parallel?
In series, you just add the resistor values together to find the total resistance. In parallel you can use the following equation you can find the total resistance by multiplying the lowest and highest resistor value, the dividing that by the sum of all the resistor values you have in parallel. you could also take the inverse of all the inverses of you resistor values added together.
How do you check resistor values in PCB?
using the color coding method
What is precision resistor?
A precision resistor is a resistor that has an actual value that is very close (or precise) to its nominal (or stated value). Therefore, precision resistors have a very degree of accuracy of being very close to their nominal values.
How do you read the value off a resistor?
Scroll down to related links and look at "Color Code Calculator - Resistor values with 4 and 5 color bands".
What are nominal values?
Nominal values are the values that a component is specified to be. For example, the nominal value of a 10K resistor is 10K. Its actual value may vary, though, based on its tolerance.
