I’ve been trying and failing to find a dimmable LED bulb for one of my lights. What makes a bulb “dimmable”? What will happen if I use a non-dimmable bulb instead? Will I die? Or just burn to a frazzle?

It won’t dim, one would assume, it’ll be on or off?

Followed by DEATH. Sorry.

In my experience, they’re fine with the dimmer at full power, then when you dim then they either
A) go into a funky disco strobe mode
2) work for a bit, then decide working is a bad idea.
iii) just stop, and only work on maximum attack.
c) work fine.
So, errr, any of them. But I’m 78% sure I haven’t died.

Not sure about LED but if you put non dimmable compact fluorescent lamps on a dimmer switch they used to strobe really badly due to the thyristor chopping the AC sine wave.

What sort of a dimmer are you using to drive the light?

I’ve not tried any non-dimmable bulbs on my various dimmers but I have had success using Varilight dimmers and dimmable LED bulbs – the MK dimmers were no good.

FWIW – my understanding was that and incandescent bulb is made dimmable by reducing the supply voltage; the dimmer would be a potential divider (not an adjustable resistor). An LED bulb is made dimmer by reducing the frequency at which you give it current and voltage and/or by reducing the current supply.

I may be wrong, a bit of googling would correct me…

they used to strobe really badly due to the thyristor chopping the AC sine wave.

Cant you compensate for this with a phlagelum regulating the spherical flux gyroscity?

the non-dimmable led bulbs I’ve run in dimmers before have all flickered then died a horrible death, in about 10 seconds. I got better.

FWIW I also tried cheap dimmable bulbs as well.
6/10 if them went within 6 months. When the 6th one went, by some massive coincidence, the expensive switch snuffed it at the same time. Replaced bulbs with much better ones and switch with the same type, and all are now at least 3 years old without a single failure.

My experience of non dimmable is they just buzz annoyingly when dimmed.

Screwfix own brand Sylvania lamps dim OK on a British General LED dimmer in my experience, although it reaches a point where they’ll flicker and go off.

Anything else flickers unpleasantly with a strobe effect.

Consider the IKEA range of dimmable LED bulbs. I’ve been very happy with their performance.

There are two types of switches too – leading edge and trailing edge (IIRC) so much will depend on the dimmer switch you have.

I suspect they reduce the life of the dimmer (with prolonged use) – based on the dimmers I’ve had to replace being used with the wrong type of bulb.

Do you have HIVE? Or similar?

My hive bulb brightness is controlled by my phone.

All hive bulbs are dimmable

OK on a British General LED dimmer

These are the dimmers I found to be poor – with both Philips, Amazon and random brand dimmable LED bulbs. All the above are spot on with the Varilight dimmers.

But to answer the question you actually asked – if you use a non-dimmbale bulb with a dimmer, use it either full on/off and you might be ok. Attempting to dim may kill the bulb.

I only recently discovered that specific dimmer switches are required for LED lights to prevent noise and strobing. I haven’t swapped mine yet so can’t confirm.

Take a look here for bulbs.

Hmm – Im thinking my dimmers are not LED comaptible. I never imagined it would matter, and the electrician that installed them didn’t mention it 🙁

It was this one I am looking for:
https://www.any-lamp.co.uk/osram-halopar-20-75w-30d

Think I found a replacement at mygreenlighting.co.uk. We will see !!

What I’m looking at getting when I get around to it are these.

It is pretty straight-forward to get the correct type of dimmer and they will swap over very easily:

https://energytoday.biz/blog/can-you-put-led-lights-on-a-dimmer

If you can’t be bothered to read it, basically you need a trailing edge dimmer and older dimmers are normally leading edge. So if it is an existing old switch it may not be compatible with LED bulbs.

Non-dimmable lamps have their own driver built in which will fight against your dimmer.
Dimmable lamps are just the lamp and need to have an external driver/dimmer.