I have a 12v SLA battery from an old UPS and two 10w led. I'm new to these stuff.
I connected one LED directly to the battery and in about 15mins it go hot and now one row doesn't work. I didn't know that we had to limit current to leds. So my question is, What is the most efficient way to drive this 10w led using a 12v SLA ? Adding just a resistor will waste about 2watts right ?
As I'm new to electronics, please draw me a circuit schematic 🙂
Best Answer
A switching converter with current limiting setting is what you need, don't go building one yourself as layout of switched converters is critical.
Luckily cheap modules can be bought that do everything you need, get one like this: http://www.ebay.nl/itm/DC-DC-LM2596-HV-S-60V-3A-Constant-Current-Voltage-CC-CV-Step-Down-Buck-Module-/281858238205?hash=item41a00f66fd:g:7nEAAOSwEgVWSYuw there's an adjustment for voltage and current, allowing you to set it to 12 V, 1 A which is exactly what these LED modules need.
Also: these LED modules need cooling mount them on a heatsink !!!