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When should resistors be used?
One of the most common uses of a resistor is to limit the amount of current in part of a circuit. However, resistors can also be used to control the amount of voltage provided to part of a circuit and to help create timing circuits.
Is having a resistor in a circuit a good thing or a bad thing?
Resistance can be both good and bad. If we are trying to transmit electricity efficiently from one place to another through a conductor, resistance is undesirable in the conductor. Resistance causes some of the electrical energy to turn into heat so some electrical energy is lost along the way.
When would you use a resistor in an Arduino?
A resistor would be used in an Arduino output pin to limit current, maybe into an LED or a transistor or other component that has a low impedance. You may wish to use a resistor in a potential divider connected to some resistive sensor ( maybe an LDR or a Thermistor ) to allow an analogread() function to measure the sensor output.
Why do I need resistors on my microcontroller?
Since you don’t have anything to limit the current there’s only the (low!) resistance of the output transistor. The current may so well be higher than 40mA, and your microcontroller will suffer damage. Without load the output voltage is 5V as expected.
How are resistors used in real time systems?
A pull up resistor is used in logic circuits to ensure that a pin is pulled to logic high in the absence of an input signal. Microcontrollers are used in embedded systems which are real time systems. Because of this the microcontrollers are sensitive to the smallest change in their inputs.
When do you remove a resistor from a circuit?
Electrical noises in the circuit will cause wide array of problems. Due to these electrical noises, the input of the gate becomes high or low. Hence a connection is needed to connect the input pin to electrical potential when the switch is open. This connection should be removed when the switch is closed.