It was the "Media Lite" (I haven't yet figured out where the 'media' fits in!) -- an old lantern with twin one-foot fluorescent tubes that put out a fair amount of light. The circuit was rather complicated, with twin inverters running off a 12 V battery, with provision for running either off the mains or as an automatic 'emergency' light when the mains failed. Perhaps its only weak point was that the batteries would conk out within about 15 minutes with both the tubes going, or a more practical half hour with just one tube running. The circuit, unfortunately, had no cut-out that might have saved the battery when its voltage fell to unhealthy levels.
Soon, like most battery-powered emergency lamps that are neglected till the season of power cuts, this too stopped working. Attempts at rejuvenationg the inverter circuit met with only partial success, and soon it joined the many other 'pieces of tech' that were gathering dust and cobwebs on a backroom shelf. But its association with my friend had persuaded me to 'save' it and put it into cold storage.
After a dusting and "gutting" of the wiring and the old PCB, I gave it a good 'bath' with a soft brush and some shampoo. The lantern emerged, well, almost as good as new.
with two LED strips (the photo above shows only one strip now) wrapped in an interleaving helix, which gave better illumination and did not put any mechanical strain on the LED strips too, unlike a smaller tube. The original 12 V battery was available no longer, but as luck would have it, a couple of standard (cheap!) 6 V 'emergency lamp' batteries, connected in series, dropped into the battery chamber perfectly.
Again, in order to keep the circuit simple, for the present I have not used a mains failure auto switch-on. That meant it was an afternoon's work to wire up the circuit and 'commission' the lantern -- EASY!!
Surely this looks like an 'evolving project', and I would be happy to present some mods/additions in the near future. The full circuit and 'fully finished' phots will have to wait for another post as I had only about 1.5 M of LED strip in hand (just enough for one helix) and there was a shortage in the parts shops. You will find that helical winding will 'eat up' a good length of strip before you know it. Considering the 'precious nature' of the old lantern, I was in a hurry to have it switched on and enjoy the 'sweet light' from an old faithful!
Here is a picture of the working lantern and I am glad it is very bright and with one more LED strip added, it might well achieve the level of illumination of the original, though I have a feeling that the bright LEDs call for a diffuser rather than a clear 'chimney'.
The hobbyist is referred to the earlier posts regarding the internal 'wiring' of the LED strip, electrical safety, --which is of paramount importance if one is to continue with one's hobby ! -- esp. where the circuit is connected to 240 VAC mains, etc.
Many of you are likely to have a couple of fluorescent tube-based old emergency lamps in your junk box. A conversion strategy could be based on my experience. The only thing to remember is that the LED strips that are available currently in the market are wired for 12 V, and that makes it mandatory to have space for two 6V batteries within the housing. However, once the old PCB is jettisoned, most lantern bodies would accommodate two batteries one above the other, I feel. Again, your ingenuity alone is the limit when it comes to breathing new life into an old lantern that might have some precious associations from the past.
Until the next post, happy conversions !!
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