Diy dimmer problem

[barney 66]

I have been using a dimmer that a lot of people are using in here off ebay 12 volt 8 amp,its been working fine until Sat night rpobably had the lightt force with a 100 watt bulb on a bit longer than i have up up now,as there were bonfires about with a few fireworks i thought that was what i could smelluntill it stopped working,it stopped dimming and just stayed on full.

 

When I opened it on Sunday the small black thing with soldered post which I presume is a chip was melted and came unsoldered,question is does anybody electronicly minded know the spec of this as i googled the numbers and came up with nothing as i would like to remotely mount one on a heat sink.

 

I measured the current when connected to a 12 volt dry cell battery and it was under 8 amps and these are rated at 8 amps but that would be different on my Landrover battery when it is running and charging so i have been told this could have been the cause as current draw would be higher,I have been told to put a socket with a zener diode in line to keep the voltage consistant at 12 volts,could someone in the know point me towards one of these rated at the right spec to handle that currnet please.

 

Sorry for the long post and i know these are only cheap but it is inconvenient when you are out so i dont want this to happen again that is why i would rather put a little effort into making it last when i buy another,or if anyone has other ideas of stopping this problem.I have limited knowledge on this subject by the way,as i am not an electrician nor an electronics expert but can do basic vehicle wiring.

 

Thanks for looking barney