Ahsanul haque

Member • Sep 17, 2013

## Calculating impedence.

Hello

I have three Led's with forward drop of 1.7 V and 10

milliamp current. I am using 9 V battery with 15 miliamp. I used this

website that gave me value of resistor to be used when LED in series or

in parallel.

For 3 led in Series, value is 390 ohms, i.e.

9V-(1.7*3)V/0.01= 390 Ohms

For 3 LED in 'Parallel', it states voltage drop of 243.33 Ohms ??

Can anyone please advise me on what formula i need to use to LED in parallel to derive this value?

I have three Led's with forward drop of 1.7 V and 10

milliamp current. I am using 9 V battery with 15 miliamp. I used this

website that gave me value of resistor to be used when LED in series or

in parallel.

For 3 led in Series, value is 390 ohms, i.e.

9V-(1.7*3)V/0.01= 390 Ohms

For 3 LED in 'Parallel', it states voltage drop of 243.33 Ohms ??

Can anyone please advise me on what formula i need to use to LED in parallel to derive this value?