When I first took a microwave triggered lamp apart in a video I joked about the hidden chip being a standard PIR body sensor chip - and was then aghast to find that it WAS. Which meant that all the microwave signal generation and movement detection was being done by a single transistor and some cunningly designed PCB tracks. I'll openly admit that microwave circuitry is such a specialist area where the only people who truly understand it are those who work with that type of circuitry all the time. It's not just a specialist area of electronics, but a specialist subsection of RF design where simple things like tracks stop behaving like conventional conductors. Now I understand this circuitry better it all makes a lot more sense. It's got strong similarities to the Colpitts oscillator FM micro transmitters I used to make for the 88-108MHz frequencies - not 300MHz as I mentioned in the video. (Well not deliberately.) The chip being used on this breathtakingly cheap and versatile module is a customised BISS0001 with a rarely used pin repurposed as the input to an internal 3.3V voltage regulator. That removes the need for a separate regulator on the PCB. Here's a search link to find these modules on eBay. Target price less than a US dollar each:- https://www.ebay.com/sch/i.html?_from=R40&_nkw=microwave+module&_sacat=0&LH_TitleDesc=0&_sop=15 If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- http://www.bigclive.com/coffee.htm This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty. ... https://www.youtube.com/watch?v=Hf19hc9PtcE

While browsing for unusual modules on eBay I came across an odd little unit intended for keeping the interiors of fridges or other small spaces sterile. Before anyone starts indignantly announcing that the correct way to keep your fridge sterile is to clean it regularly, I should mention that the main point of this device is to stop transfer of odours from stinky cheeses and other aromatic foods, and also to prolong the life of exposed food by limiting the growth of bacteria or mould. The unit claims to put out positive and negative ions, and it does have a carbon fibre emitter for each that does indeed have a matching charge. However, the main characteristic of this unit is the slight hint of ozone. Ozone gas (an unstable 3-atom oxygen molecule) is increasingly being used at low levels in catering environments to reduce the risk of food poisoning and prolong product shelf life. The power consumption of this module on 240V is very surprising. Just a fraction of a watt at 0.01W (ten milliwatts). Before de-potting this unit I had a guess at what might be inside. I expected the common circuit based on discharging a capacitor in pulses through a small high voltage transformer, but I was completely wrong. It's a very neat little circuit, but quite perplexing as the component count is much lower than expected.for the style of circuitry. Here's a search link for the 220-240V version of this module:- https://www.ebay.com/sch/i.html?_from=R40&_nkw=TFB-YA2102&_sacat=0&_sop=15 Here's a search link for the 110-120V version of this module:- https://www.ebay.com/sch/i.html?_from=R40&_nkw=TFB-YA1102&_sacat=0&_sop=15 Here's a search link for the 12V version of this module:- https://www.ebay.com/sch/i.html?_from=R40&_nkw=TFB-YD12102&_sacat=0&_sop=15 Note that I do NOT recommend using 12V DC ioniser modules on ungrounded plug-in power supplies, as they can create a high enough voltage differential to ground to cause arcing/tracking between the low and high voltage sides of the power supply. If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- http://www.bigclive.com/coffee.htm This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty. ... https://www.youtube.com/watch?v=kutNgCsJ2Hs