Hero999
Banned
These Christmas tree lights are running from a transformer. Never use a diode in series with a significant load connected to a transformer, it will cause core saturation and overheating of the transformer!Yes, or a resistor, or a diode. The diode I²T rating has to be more than the lamp inrush current (10x to 15x the steady state lamp current for a few dozen mS). Do the diode; the lamps will last forever.
If you use a diode the cheap Christmas tree lights will probably be all right but the more expensive transformer will meltdown.
What current do the lights require?
Use a resistor to reduce the extra voltage.