Savel brain dump in English!

At last I finished (2008.02) my torchlight project. I was looking quite a long time for good LED driver. When I found driver chip, I’ve lost all my white LEDs. So I used white LEDs from bad USB web cameras’. There are 4 LEDs in one web camera. I dissasembled several ones and collected 12 (in last edition 16) bright white LEDs.

baltų šviesos diodų projektą.

Here is last PCB test before finishing assembly:

I compared light output using simple cheap incandescent bulb, but powered from one Liion battery. Bulb is 2.4V and 0.75A. As it was powered from 4…3.7V source, output power is much more. And it was very hot- plastic details near lamp melted.

“Light power” comparison:

Conclusions:

After comparing both types of the lamp I can definetely tell, that LEDs are better in case of energy use. But only if LEDs are connected using special driver chip. Cheap China torches are made without any driver and are not very good for advanced use. Looking from spent money, the situation may be different. LED driver chips and custom hardware is expensive. Another advantage using drivers chips is that light power is constant during all liftime of battery.

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This is not up to date post (post date 2008.02)

I rescanned DVB-T channels using areal antena and found some new stations. As my antenna is quite big I am receiving TV stations from some near cities. I find new transponder at 778MHz. Maybe it is TEO? During tests all channels were uncoded. Now I need card to view.
Some changes in free to air channels. Also, picture size is smaller. Size is reduced from 720×576 to 544×576. But bandwidth is same, so overall quality is same. Also, less CPU power is needed to decode TV programs. Maybe size is changed because cheap TV tuners are with very “thin” CPU.

The are only 3 channels in 786Mhz…

Screenshots:

More cropped pictures: (more…)