Non-Inverting Amplifer Based Current Source

This set of circuits demonstrates that a conventional non-inverting amplifier circuit can be used as a current source by treating the feedback resistor as a load. Here the load is an LED. The various circuits in this sketch are the same, however the way i've decided to set the input voltage is varied. Here i've used fixed voltage divider, variable divider (pot), a forward biased diode and a zener diode. There are other methods, such as using programmable voltage references, however the components were not available in the free version of Multisim Live.