I came across a constant current LED circuit at
http://electronics-diy.com/power-led-driver-circuit.php
It looks nice and easy to build. However the Calculations for the resistors and the power make no sense to me.
I want to change the N channel MOSFET for a IRF520N and the transistor for a BC547 as I have these items in my stocks.
In the diagram unless I am missing something the Mosfet looks like a P channel yet in the write up refers to an N channel and even the specified part is N channel.
I really want to work out the resistor, for the current limiting.
The LED's I have are have the following ratings
Voltage 3.2 - 3.4 Volts
Current 350mA
I want to run them from a 12 Volt supply in different strings from 1 to 4 LED's
http://electronics-diy.com/power-led-driver-circuit.php
It looks nice and easy to build. However the Calculations for the resistors and the power make no sense to me.
I want to change the N channel MOSFET for a IRF520N and the transistor for a BC547 as I have these items in my stocks.
In the diagram unless I am missing something the Mosfet looks like a P channel yet in the write up refers to an N channel and even the specified part is N channel.
I really want to work out the resistor, for the current limiting.
The LED's I have are have the following ratings
Voltage 3.2 - 3.4 Volts
Current 350mA
I want to run them from a 12 Volt supply in different strings from 1 to 4 LED's