Hello, I'm currently trying to do a little LED lamp. The LEDs are blue, with a measured 3.2V drop each. My source is 5V.
I have 100Ω, 80Ω and 20Ω resistors.
The left schematic has a 20Ω and 3 80Ω resistors, and the right one has 3 100Ω resistors.
What I want to know is if both circuits will behave the same way.
I tried to do some math and got different results, but my logic says me that both circuits are the same. Heres my math, correct me please:
LED "resistance" = 3.2V/20mA = 160Ω
For the left schematic:
1/Rparallel = 3*(1/240Ω) ---> Rparallel = 80Ω
Rt= 20Ω + 80Ω = 100Ω
Current = 5V/100Ω = 50mA
For the right schematic:
1/Rt = 3*(1/260Ω) ---> Rt= 86.7Ω
Current = 5V/86.7Ω = 57mA
This is clearly a different circuit, but for me, logically, both should be the same because the 20Ω resistor in the left "works" for all 3 of the branches, which would give each branch a 100Ω resistance. Or was my math wrong?
Thanks and appreciate any help.
I have 100Ω, 80Ω and 20Ω resistors.
The left schematic has a 20Ω and 3 80Ω resistors, and the right one has 3 100Ω resistors.
What I want to know is if both circuits will behave the same way.
I tried to do some math and got different results, but my logic says me that both circuits are the same. Heres my math, correct me please:
LED "resistance" = 3.2V/20mA = 160Ω
For the left schematic:
1/Rparallel = 3*(1/240Ω) ---> Rparallel = 80Ω
Rt= 20Ω + 80Ω = 100Ω
Current = 5V/100Ω = 50mA
For the right schematic:
1/Rt = 3*(1/260Ω) ---> Rt= 86.7Ω
Current = 5V/86.7Ω = 57mA
This is clearly a different circuit, but for me, logically, both should be the same because the 20Ω resistor in the left "works" for all 3 of the branches, which would give each branch a 100Ω resistance. Or was my math wrong?
Thanks and appreciate any help.