I was working with some smd LED's trying to make their V-I curve. For that purpose, I connected two segments parallel to each other each containing two leds as shown, to a regulated dc power supply directly.
The voltage from supply was increased gradually.LEDs started o glow as voltage reached around 4.8V with 0.07mA current in the circuit. As I increased the voltage, LEDs became brighter as expected. But after around 7.6 V, I wasn't able to increase the voltage any further. Current reading at this point was 189.8mA. The supply is capable to provide upto 30V, 2A. Why the voltage got stuck at 7.6V?