DIY: Revamp Your Table Lamp Today

How to transform a lead-acid battery table lamp? If you're interested, keep reading!

As shown in the picture below, this is a lead-acid battery table lamp. Upon inspection, the battery is no longer functional. Opening up the lamp reveals that the internal components are not in great shape either; there's leakage, and the capacitor is about to burst. These parts need to be discarded. Additionally, using a resistive-capacitive dropper in this lamp isn't advisable.

If you don't need the battery, don't want to use a power adapter, and lack a suitable constant current driver module, then a constant voltage setup will work. Prepare a 220-15V, 500mA AC-DC module that looks similar to the one in the image below.

The LED configuration inside the lamp is 4*6=24 in parallel. There are two options: you can either add a DC-DC module to step down from 15V to 3.1V, or modify the AC-DC module to output 12.4V and change the LED setup to 4 in series and 6 in parallel. If you don’t have a small DC-DC converter, you can follow this guide to modify the AC-DC module. Reduce the current-limiting resistor on the optocoupler from 10.5k to 8.6k, and the actual output will be around 12.3V. Make a cutout for a boat switch.

Change the LED board from parallel to series, and apply green paint. For added insulation, stick transparent tape on the reflector.

And there you have it! You'll achieve approximately 400mA of current.