Sansi is the company that makes the unusual ceramic core LED lamps. Having been quite impressed by their lamps I thought I'd take a look at another of their products.<br /><br />It turns out to be quite nicely designed, with logical circuitry and a very unusual fresnel lens.<br /><br />The PIR sensor is a BS612, which you can buy from Adafruit:-<br /><a href="https://www.adafruit.com/product/5578" target="_blank" rel="nofollow">https://www.adafruit.com/product/5578</a><br />It's quite a sophisticated module that does most of the work, with very little in the way of external components.<br /><br />The circuit board in this light is quite tricky to get out due to being soldered in place on the battery contacts. It will take a beefy soldering iron to desolder the negative terminal in particular, because it is on a large ground plane on both sides of the PCB that sucks the heat away from the connection.<br /><br />There is scope to replace the existing three AAA cells with a lithium cell if desired. The application might be ideal for one of the many cells found in disposable vapour products often found discarded in the street. Although the unit does not have low voltage cutout, the LEDs will be very dim by the time the voltage reaches the lower level of the lithium cell, and the current will dwindle away to the quiescent current by the point the cell needs recharged. A cell with a connector tagged onto the existing main battery terminals would allow easy swapping.<br /><br /><br />If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- <a href="http://www.bigclive.com/coffee.htm" target="_blank" rel="nofollow">http://www.bigclive.com/coffee.htm</a><br />This also keeps the channel independent of YouTube's algorithm quirks, allowing it to be a bit more dangerous and naughty.<br /><br /><br />#ElectronicsCreators<br />...<br /><a href="https://www.youtube.com/watch?v=kGS1RJTawEU" target="_blank" rel="nofollow">https://www.youtube.com/watch?v=kGS1RJTawEU</a>