How To Select The Resistor Value In a LED Circuit Using Ohm's Law

TL;DR

Learn how to calculate the resistor value in LED circuits based on forward voltage and current.

Transcript

in this video we're going to talk about how to calculate the resistor value in an led circuit so in this circuit we're given the forward voltage of the led and that's three volts and the recommended ford current is 50 milliamps so based on these conditions what is the value of r that should be used in this circuit shown below so let's write down th... Read More

Key Insights

• ▶️ The forward voltage and recommended forward current are essential parameters for calculating the resistor value in LED circuits.
• ⚡ In series circuits, the resistor value is determined by subtracting the forward voltage from the source voltage and dividing it by the forward current.
• 👫 Multiple LEDs in series can share the same resistor value, while in parallel circuits, each LED needs its resistor.
• 👮 Ohm's law is used to calculate the resistor value, considering the voltage and current across the LED and the resistor.

Questions & Answers

Q: How do you calculate the resistor value in an LED circuit with a single LED in series?

In a series circuit, you subtract the forward voltage of the LED from the source voltage and divide it by the forward current to get the resistor value.

Q: What is the resistor value in a circuit with multiple LEDs in series?

The same resistor value can be used for multiple LEDs in series since they share the same current. Use the same calculation as in a single LED series circuit.

Q: How do you calculate the resistor value in a circuit with multiple LEDs in parallel?

In parallel circuits, the voltage across the LEDs is the same. You subtract the forward voltage from the source voltage and divide it by three times the forward current to get the resistor value.

Q: What is the significance of the resistor value in an LED circuit?

The resistor value determines the current flowing through the LEDs, ensuring they operate within their recommended specifications and protecting them from excessive current.

Summary & Key Takeaways

• The video explains how to calculate the resistor value in an LED circuit based on the forward voltage and recommended current.

• It provides examples of different circuit configurations, including a single LED in series, multiple LEDs in series, and multiple LEDs in parallel.

• By using Ohm's law, the video shows how to determine the resistor value by considering the voltage and current across the LED and the resistor.