| 
  • If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • Stop wasting time looking for files and revisions. Connect your Gmail, DriveDropbox, and Slack accounts and in less than 2 minutes, Dokkio will automatically organize all your file attachments. Learn more and claim your free account.

View
 

Lab 1-Pavan

Page history last edited by Benjamin Tee 8 years, 2 months ago

1. What resistance do you need to limit current to 30 mA (if using red LED) or 25 mA (if using yellow or green)? Be sure to state which color LED you are using. This resistance refers to the total resistance in series with the LED.

 

Main Voltage = 5V

Voltage of Green LED=2.2V (Effective voltage= 5-2.2=2.8)

Voltage of Red LED=1.85V (Effective voltage= 5-1.85=3.15)

Voltage of Yellow LED=2V (Effective voltage= 5-2=3)

 

Ohms law states that V=IR

R=V/I

 

Resistance of Green LED = 2.8/0.025 = 112 ohms

Resistance of Red LED = 3.15/0.03 = 105 ohms

Resistance of Yellow LED = 3/0.025 = 120 ohms

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

2. Is the resistance from question 1 a maximum or minimum resistance? That is, in which direction if you change the resistance (higher or lower) would the LED likely fail.

 

The resistance is a minimum because according to the ohms law resistance is inversely proportional to the current and if resistance drops, the current gets higher and the LED would most likely fail(According to the data sheets for the LED's). 

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

3. What is the resistance range of the potentiometer?

 

The resistance range of the potentiometer is from 0.25 ohms - 10,000 ohms.

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

4. Does it matter what order the components of your circuit are arranged between power and ground? Why or why not?

 

No, it doesn't matter what order the components are arranged in if the circuit is in series. But if it is arranged in parallel it would matter.

It doesn't matter because it just needs current to flow through the circuit and this will happen as long as the circuit is complete.

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

5. Using this battery, what is the minimum resistance required for use with your LED?

 

Battery 

Voltage of Green LED=2.2V (Effective voltage= 9-2.2=6.8)

Voltage of Red LED=1.85V (Effective voltage= 9-1.85=7.15)

Voltage of Yellow LED=2V (Effective voltage= 9-2=7)

 

Ohms law states that V=IR

R=V/I

 

Resistance of Green LED = 6.8/0.025 = 272 ohms

Resistance of Red LED = 7.15/0.03 = 238.34 ohms

Resistance of Yellow LED =7/0.025 = 280 ohms

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

6. Make a Video of Your LED Being Switched On and Off.

 

Fliqz has shut down their service. To access this video, email support with this video id: 3832b94bf6d94ef0b43a5ca9363dbe57

Comments (1)

Benjamin Tee said

at 12:21 am on Jul 11, 2012

Clear and concise! Nice job Pavan!

You don't have permission to comment on this page.