Big day

Big day for me, my first PCB has arrived thanks to norcot.

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Now just have to see if did a good job and they work!

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DiveTorch Update

Its been a while since my last update due to lots of other ongoing work. However progress is being made with the torch. Firstly some problems, then some progress.

I discovered the LM2733 Boost convertor was nowhere near beefy enough to drive 45V at any kind of power so this has lead to the abandoning of the CREE 45V LED and instead ive designed in a more suitable 12V Bridgelux. The change will result in a less powerful torch but after much consideration i decided that the point of the project was to experiment with switch output underwater and not to make the most powerful torch possible.

See the Pictures below for LED’s side by side.

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Next big change is my decision to swap the PIC16F for a PIC24F, with a smaller package and less pins the PIC24F will save some space on my board although this isnt the main reason for this change. The PIC16F used a Hi-Tech compiler to compile my C code to the apropriate asembly languare for my uC. The PIC24F uses Microchips C30 compiler which has a much bigger development community and support network available. Hopefully this will be useful in the future as i look to increase the complexity of my torch i can leverage some pre written open source code.

Lastly but by no means least ive connected the LED to the uC via a IRLL024 MOSFET. This MOSFET should handle fast switching of 1A easily (see graph below) with a Vgs ~2.7V. This Choice also provides possibilities for higher current switching with some redesign of the project.

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Dive torch upgrade project

A little while ago I started to look into upgrading my UK400 scuba diving torch. The current model has a halogen bulb that I would like to replace with an LED.

So far this is what I have.

There are two seperate power supplies. One for DCin to 3v3 which will act as power for the digital electronics and the other for DCin to 45V which will the the ‘high voltage & high power’ rail for the LED. datasheets for relivent parts are attatched for those interested, and ill add full circuit diagram etc when everything is finalised.

PIC16F193.pdf
Download this file

Max15007_3v3.pdf
Download this file

CREE_1305819-_LED.pdf
Download this file

LM2733_-_boost_conv.pdf
Download this file