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Showing posts from July, 2019

What is potentiometers How a Potentiometer Works?

Potentiometers A potentiometer is simply a variable resistor that can be controlled by the user. Potentiometers accomplish this by having three terminal resistors forming and a load that connect the potentiometer and the voltage source in one loop and the potentiometer and the load in another. Potentiometers have a wide range of uses, ranging from CD players to Servo mechanisms. How Does a Potentiometer Work? A potentiometer has 3 pins. Two terminals (the blue and green) are connected to a resistive element and the third terminal (the black one) is connected to an adjustable wiper. The potentiometer will work as a rheostat (variable resistor) or as a voltage divider. Rheostat To use the potentiometer as a rheostat, only two pins are used: one outside pin and the center pin. The position of the wiper determines what quantity resistance the potentiometer is imposing to the circuit, as the figure demonstrates: If we have a 10kΩ potentiometer, it means that the maximu...

What is a Low-dropout Voltage Regulator?

A low-dropout voltage regulator is such a regulator that can work at a very small input-output differential voltage, that means this voltage regulators can regulate the output voltage even when the output voltage is extremely getting ready to the input voltage. If you use a standard linear regulator(for example a 78XX), you need a minimum difference between input and output voltage of about 2V, so if you want 5V, you have to provide minimum 7V as its input. If input goes below that voltage the regulation can not work. This 2V margin is named dropout voltage, you'll realize it within the datasheet of several part. Low-dropout voltage regulators have much lower dropout voltage about 0.5V-1.5V. So why do we need this? As for the linear voltage regulators, the lower the difference between input and output the higher the efficiency it will have because the power dissipation of the device is usually the difference between input and output voltage increased by the current its sup...