I have a task to drive four LEDs from a 4-20mA loop. I have 24V for the LED side so I need to convert the current into something that can drive the LEDs.
I know I can use a 250\$\Omega\$ resistor as the converter in the loop which will give me 1-5V from 4-20mA respectively, now I need to get this voltage to drive the LEDs.
Do I simply connect a transistor base to the 1-5V point, ground the emitter and drive the LEDs from the 24V via dropping resistors via the collector??
It needs to be a variable drive as the brightness of the LEDs must vary with the 4-20mA signal.