I modified an Ikea LED light with some colour changing LEDs while reusing the original power supply.
- The power supply delivers about 6.1 V with original LEDs
- The colour changing LEDs are rated 3-3.4 V each, so two in parallel should work fine.
- The original LEDs draw about 190 mA
- Two colour LEDs draw about 16 mA, so 10 should work fine with the power supply.
- At 6.1 V all LEDs draw up to about 81 mA
- On the Ikea power supply they draw about 180 mA. Turns out the power supply went up to 10.8 V
- After adding 110 Ohm resistance (100 + 10) Voltage goes up to about 6.8 V.