In: Electrical Engineering
When i went to the lab, and measure the output voltage of the VOLTAGE REGULATORS in the Arduino Uno by connecting it to either 12 voltage or 9 voltage, The output was the same which is 4.94.
I need the equation to calculate and calculate it with full steps mathematically
Voltage regulators provide the fixed voltage, irrespective of the variation in the input voltage. As you have said that the measured output voltage is 4.94, it means, there is a 7805 voltage regulator. The number 7805 has a meaning. 78 denotes the positive voltage regulator and 05 represent the output voltage. For example 7812, it is a positive voltage regulator with the output voltage of constant 12V, 7809 is a positive voltage regulator with a constant output voltage of 9V.
These voltage regulators can accept the variable input voltage and can produce a constant output voltage. Let us take a look at the datasheet of the 7805 voltage regulator.
You can see that the input voltage range is from 7V to 25V. This is the answer to your question. You were using 9V and 12V input voltage, they come in 7-25V range S, the output voltage is equal to 5V approx.
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