LED bulb explodes

helpneeded2014

Just a LED bulb explode into tons of small bits never seen a bulb do this before, anyone else had this problem.

stator

Never heard of an LED bulb exploding.


Did it overheat? Some spotlight holders don't work well with LEDs because there isn't enough room for the airflow to keep the transformer cool.

helpneeded2014

stator wrote: »

Never heard of an LED bulb exploding.


Did it overheat? Some spotlight holders don't work well with LEDs because there isn't enough room for the airflow to keep the transformer cool.

How would i know if it over heated ? i just turned it on and bang it's the bulb we have in the hallway

FreeBear

LED bulbs have a small electrical circuit buried in the back - Most use a capacitor to drop the mains voltage down to a usable level before it is rectified and fed to the individual LED elements. This capacitor is highly stressed, and if the bulb manufacturer sourced a cheap one, it is quite possible that it failed. Capacitors can experience uncontrolled & spontaneous deconstruction, and switching on could be just the trigger needed. Just have a look on youtube for exploding LED lamps..

shaun_from_Africa

Where did you buy the LED lamp from?
If it was ebay or similar then it could well be a cheapo Chinese made one which wasn't up the same standard as some others.

FreeBear wrote: »

LED bulbs have a small electrical circuit buried in the back - Most use a capacitor to drop the mains voltage down to a usable level before it is rectified and fed to the individual LED elements.

A capacitor can't be used to drop voltages, this function is carried out by a transformer.
Capacitors are in a circuit to either store a charge or to help smooth out any ripple in a DC signal.

FreeBear

shaun_from_Africa wrote: »

A capacitor can't be used to drop voltages, this function is carried out by a transformer.

A capacitor has a property called "impedance" - In an AC circuit, a capacitor will exhibit some of the characteristics of a resistor and can be used to drop a voltage.


https://en.wikipedia.org/wiki/Capacitive_power_supply
https://www.electronics-tutorials.ws/capacitor/capacitive-voltage-divider.html

chrisw

shaun_from_Africa wrote: »

A capacitor can't be used to drop voltages, this function is carried out by a transformer.
Capacitors are in a circuit to either store a charge or to help smooth out any ripple in a DC signal.

LED bulbs tend to use transformerless power supplies, using capacitors and resistors.

Here's an example circuit:-

https://www.etechnog.com/2018/06/working-of-modern-led-bulb-with.html

forgotmyname

Yep, hone one go pop also. It was one of the UFO camping lights from the £ shop.

Popped the batteries on and one LED glowed orange not white, turned over to check the batteries and it went pop and scattered itself. Luckily it was facing downwards and not in my face.

Would never have expected it from an LED and just 4.5volts.

shaun_from_Africa

Thanks for the info Freebear & chrisw.

I've learnt something new today.