How to Protect Christmas Chasing Bulbs Set

I agree with lynlynch. An alternative you could consider is using something like a variac (a variable autotransformer) to gradually reduce the voltage to the lights in proportion to the number of lights burnt out.

(This is assuming that there is a series arrangement of lights in those strings.)

But the cost of a variac, and then the fiddleliness of adjusting--I'm sure you'd be better off buying LED lights to replace what you have.)

How about re-using the ones from Diwali instead?

Where are you that you are using 240V for this application?

Somewhere not in the USA/Canada/US Dominions I guess.......

Most of the world uses 220volts AC nominal......it saves on copper. And weight!!

You know, typically in the U.S. these things run on 120V (or sometimes described as 110V) voltage. A 240V Christmas light system, oh boy...should light up the neighborhood.

On a world basis, 220volts single phase house mains is the norm.......

I actually have 3 phases at 220 volts phase to neutral coming into my house.......as does most of Germany.....its the norm here to have 3 phases. we can use quite large circular saws and lathes etc....

In the UK its generally a single phase......but still 220 volts.....phase to Neutral.

Other 220 countries I cannot say which ones are single phase and which are 3 phases (into private houses)....

A possible way to use the strings with a lower voltage when lamps are busted occurred to me today.....

But only if you are a good electronics person as it could be dangerous......

Convert the local AC to DC at (in your case) 220 volts. Using high voltage diodes....

Then build a PWM (Pulse Width Modulation) for high voltages and use a pot to reduce the average voltage to keep the lamps burning at a reasonable brilliancy......

The lamps will work just as well on DC or AC........

Again, this is a dangerous way to go if you are not good with mains or electronics.....

A possible way to make it safer is to cut the string into 4 with each having an equal number of lamps on each string, and link them together in parallel, then you can transform down to around 50 volts and then add the PWM circuit.......50 volts DC is far less dangerous that 220 volts AC or DC and the electronics will also be far cheaper.....but an extra transformer will be needed....

There could be a better way or two.......an autotransformer would be better but expensive....