How Resistance Work with Practical Example

How resistance can protect a circuit in a practical application:

  • Resistance can protect a circuit by limiting current, regulating voltage, and dissipating heat.
  • Current limiting: A practical example of current limiting using resistance is in a simple LED circuit. If a resistor is not present in the circuit, the LED will draw too much current and burn out. However, by adding a resistor in series with the LED, the current can be limited to a safe level that will not damage the LED.
  • Voltage regulation: A practical example of voltage regulation using resistance is in a power supply circuit. If the voltage output from a power supply fluctuates too much, it can damage components downstream. However, by adding a resistor in series with the output, the voltage can be regulated to a more stable level that protects downstream components.
  • Heat dissipation: A practical example of heat dissipation using resistance is in a power transistor circuit. Power transistors can generate a lot of heat during operation, and excessive heat can damage them. By adding a resistor in series with the transistor, some of the current will be converted into heat, which can help prevent the transistor from overheating.
  • Current Limit: A practical example of current limiting using resistance is in a surge protector. Surge protectors use resistors to limit voltage spikes and protect connected devices from damage. The resistor drops some of the voltage and prevents it from reaching the connected devices, which protects them from damage.
  • Overall, understanding how to use resistance effectively is crucial for designing safe and reliable circuits in a wide range of applications.

Effect Of Resistance On LED

  1. Current through the LED is 915mA while absolute maximum is  20.0mA therefore the LED blows.
  2. Current through the LED is61.9mA while the recommended maximum is 20.0mA the usable lifetime of the LED may be reduced. 
  3.  The resistor limited the current through the LED . Therefore the LED is working at its optimum.

In conclusion, resistance plays a critical role in protecting circuits and ensuring their reliability. By using resistors to limit current, regulate voltage, and dissipate heat, engineers and technicians can design circuits that are protected from damage and perform optimally. Understanding how to use resistance effectively is crucial for designing safe and reliable circuits in a wide range of applications.