I bought this meter decades ago while picking up some material from an electrical distributor. It's a super simple light meter, but is not bad as a rough indicator of intensity in a room. The schematic is breathtakingly simple, as shown. 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 ... https://www.youtube.com/watch?v=VOXRJgw_Mg4

I bought one of these little Cheerson CX10 quadcopters from an online supplier and when it arrived it was a bit frustrating to get going because the instructions were not in very good English. But I worked it out and it's a great little thing. The purpose of this video is to save you the grief of decrypting the instructions so you can just get on with playing with the thing. Things worthy of note are that there are two types of blade. Clockwise and counterclockwise. If you put them on the wrong motor the quadcopter will do very weird things. I recommend putting a marker pen dot on one diagonally opposing set of blades as soon as you get it. There are spare blades of either type and you will need to compare them for the way the blades slope if you have to put new ones on. The charging circuitry is built into the USB plug. A red LED shows when the charge has completed. Do not leave the quad on charge continually and do not leave the charging lead plugged into it when it's not charging as it may run the battery down. There are two types of controller. Left hand throttle and right hand throttle. The throttle makes the blades spin faster and the quad lift upwards. It's the only joystick movement that doesn't have spring loaded return to centre. That same joystick also does the "rudder" function that makes the quad spin on the spot in either direction. The other fully spring loaded joystick is for backwards, forwards, left and right (in non geek-speak.) The remote control needs two AAA alkaline cells to operate. After charging the quad you will need to pair it with the remote controller each time you use it. To do this, turn on the quadcopter and place it on a flat surface. It's LEDs will be blinking. Place it with the red LEDs towards you (it's rear). Then make sure the remote controller has it's throttle joystick fully moved towards you (the side with the on-off button) and then turn the remote controller on and after a moment push the throttle fully forwards and you'll hear a beep and see the quad's lights react. Now pull the throttle fully back again and you're ready to fly. To calibrate the quadcopters accelerometers/gyro put it on a flat surface and push the non-throttle lever up to its top left position and then move the throttle lever to its lower left position. If successful the quad's LEDs should blink on one side after a second or two. To fly the quad after pairing, ease the throttle forward slowly until the quadcopter starts lifting off the ground. It requires a delicate balance to keep it at a specific height, so don't get too violent with the throttle lever. If the quad drifts in still air then you can compensate with the two pairs of trim buttons that adjust the effective centering position of the steering control. After that it's really just down to playing with it to get a feel for how it flies and behaves. If it crashes put the throttle down to the bottom position immediately. But if the motors stall the quad will go into standby mode immediately and flash all its LEDs to aid location. It will need switched off and on as will the controller for pairing again. If the quad refuses to fly and just flashes its LEDs then it may need recharged. Enjoy. These things are great to play with. ... https://www.youtube.com/watch?v=B6gAhHVYieA

Although this detector came from Temu (not a sponsor) it is widely available from many online sales platforms. Its purpose is to help you locate concealed cameras in your home or temporary accommodation. It does that by firing out a bright ring of red light, which you can then view centrally for retro-reflections from lenses. The use of a dichroic glass filter is unusual for something like this, and quite a nice touch. The circuitry is very simple, since the unit relies on the skills of the user to differentiate what might be causing a reflected pinpoint of light. It's intended for use by someone knowledgeable about what they are looking for and the areas a secret camera might be covering. If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- https://www.bigclive.com/coffee.htm This also keeps the channel independent of YouTube's algorithm quirks, allowing it to be a bit more dangerous and naughty. #ElectronicsCreators ... https://www.youtube.com/watch?v=J5ctijPFLyY

Having seen an interesting LED wiring loom used in a particular style of decorative light in the past, I was surprised to find it on AliExpress during a search for signage components. It's basically a long series string of two pole XH type connectors designed to allow easy connection of a string of LEDs in series on a non-isolated capacitive dropper power supply. That allows a large number of individual LEDs to be powered from a cheap and simple power supply. The downside of this system is that every socket poses a shock risk due to a lack of shrouding of live metalwork. That makes it particularly awkward that this system was used on a fashionable decorative light range that had the LEDs stuffed randomly throughout a structure wrapped with spiral aluminium wire, and in amongst "flowers" that were more coiled aluminium wire scrunched together. I don't think they were earthed/grounded, which makes me wonder how many people got tingles off the lights. The newer ones seem to have switched to using strings of sleeved LED Christmas lights. In a cheap signage application I could see this being used in window signs where LEDs were poked through the wooden or plastic front and then interconnected with these strings of sockets. The simple capacitive dropper style supply means this circuitry will work with 120V supplies too, but will drive less LEDs (about 50 per circuit). The red coloured 400V dropper capacitor can be changed to alter the LED current. 100nF to 680nF are suggested values. Although I ordered three strings of these, expecting three bundles of 100 connectors, what actually arrived was one 100 connector bundle of random detached lengths as if I'd been sent offcuts. All the more suspicious that there was a defective section with one intermittently open circuit link. Very hard to narrow down when it flickers with the slightest movement of any sockets in the vicinity, and they are potentially live at around 300V. (There was a mis-crimped wire.) The seller did give a refund for the two missing looms. When terminating the wire into the power supply (after a circuit upgrade) I found that the loom wire did not take solder, and may be aluminium. I'm not sure how well that bodes for crimp reliability. If used, this is definitely the sort of loom that should be built into something and not used where the individual holders can be touched, as they do pose a shock risk. Likewise, I recommend taking suitable precautions while working with it. (Gloves and avoiding grounded surfaces.) Here's a listing from a different supplier:- https://www.aliexpress.com/item/1005004380896591.html 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 algorithm quirks, allowing it to be a bit more dangerous and naughty. #ElectronicsCreators ... https://www.youtube.com/watch?v=VxjS0NUUDko