What Are the Uses of RC Filters in Advanced Circuits?

  • Thread starter potatocar
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In summary, resistors are used to control voltage and current in a circuit and can also be used for generating heat. They are necessary for various applications, such as light bulbs and filters, and without them, a perfect circuit would be impossible to achieve.
  • #1
potatocar
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I don't understand why we use resistors at all. I've read that they cause a voltage drop and decrease the flow of electrons (current). Why is this useful? If we want to decrease the current, why not just lower the voltage? Don't resistors just waste energy?
 
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  • #2
potatocar said:
Why is this useful? If we want to decrease the current, why not just lower the voltage? Don't resistors just waste energy?
And how will you lower the voltage at different points in a circuit?.
 
  • #3
bp_psy said:
And how will you lower the voltage at different points in a circuit?. .

So it's only because the same voltage supply is used for different "things" (that require different currents to flow through them)?

Also notice that ohms law gives very high currents for very low resistances even if your voltages are low. Of course ohm law doesn't always hold but it still gives you a good idea

Do you mean if R<1? So.. a resistor can increase the current?
 
  • #4
potatocar said:
So it's only because the same voltage supply is used for different "things" (that require different currents to flow through them)?
Yes the main use of resistors is voltage control and current control.
http://en.wikipedia.org/wiki/Current_divider
http://en.wikipedia.org/wiki/Voltage_divider

potatocar said:
Do you mean if R<1? So.. a resistor can increase the current?
The current always decreases with increasing R. What I meant was that it would be very hard to adjust the current in a low resistance circuit just by adjusting the voltage. I edited that out because It might be confusing and maybe not a very useful way to think about it.
 
  • #5
potatocar said:
I don't understand why we use resistors at all. I've read that they cause a voltage drop and decrease the flow of electrons (current). Why is this useful? If we want to decrease the current, why not just lower the voltage? Don't resistors just waste energy?

Resistors are also useful in generating heat. For a current I through a resistance R, the powerloss is P = I2R which manifests itself through heat (this is how circuits overheat and stop working or burn). Using this idea, you can use this heat in applications such as light bulbs, electric stoves, soldering irons and so on.
 
  • #6
A perfect circuit would encounter zero resistance. Love to see somebody build it. You would be a trillionaire. Power my AC with no resistance LOL
 
  • #7

1. Why are resistors important in electronics?

Resistors are essential components in electronic circuits as they limit the flow of electric current and regulate the voltage. This allows for precise control of the electrical signals and prevents damage to other components.

2. What is the function of a resistor?

The main function of a resistor is to resist the flow of electric current. This can be used to control the amount of current in a circuit and adjust the voltage level. Resistors are also used to convert electrical energy into heat.

3. How do resistors affect the performance of a circuit?

Resistors play a crucial role in the performance of a circuit. They help to stabilize and regulate the flow of current, maintain the voltage level, and prevent overheating of components. Additionally, resistors are used in various electronic devices to reduce noise and improve signal quality.

4. What are the different types of resistors and their uses?

The most common types of resistors are fixed resistors, variable resistors, and specialized resistors such as thermistors and photoresistors. Fixed resistors are used to limit current and regulate voltage, while variable resistors are used for adjusting the resistance in a circuit. Specialized resistors have specific uses such as temperature sensing or light detection.

5. How do resistors affect the power consumption of a circuit?

Resistors consume power by converting electrical energy into heat. The amount of power consumed by a resistor is determined by its resistance value and the amount of current flowing through it. In some cases, resistors may be used to reduce power consumption by limiting the current in a circuit.

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