Can anyone read the marking on this mystery tantalum capacitor? It is from the mid-1980s motor Jay Electronics driver board (hopefully) undergoing resurrection. Of three capacitance meters here, only one will make a stab at it in-circuit, where it reads ~600nF either way around. V47 seems an odd marking.
At last, some ‘spare’ time this weekend, and I learned two things about SCR dc motor control: Permanent magnet dc motors need a chunky inductor in series with them if they are fed from an SCR (thyristor) based mains power controller. It is (probably!) possible to safely interface an Arduino to such an SCR controller. This was the result of ...
3D printing prototype enclosures with PLA or PETg is quick and easy, but to which filament to you turn if the enclosure has to be installed somewhere, and therefore need to be flame retardant. Such low-flammable raw material does exist, but it has not been easy to find it – until now as Bambu Labs has introduced ‘PC FR‘, a ...
Castle Wonderland had one of the first fully-dimmable LED-lit rooms anywhere, when, in 2011, I made up 11 luminaires, each with an early 3W Cree led, and wired them in series for one of the ceilings here. It was my first experience of having aluminium and Perspex laser-cut – excellent fun. Initially, an commercially-made mains dimmer module was used, which ...
Pondering the good-enough isolated probing circuit I soldered up yesterday (repeated below), I wondered if there was a ‘100%’ clean alternative that was not much more complicated and would not have the slightly soggy, although acceptable, characteristics. (That said the led still gets brighter and dimmer when it is ‘on’, depending on cell voltage). Without making it – so bare ...
Following the connection of a new computer monitor, probing on one of the small CNCs packed up. Rather than find another monitor, a totally isolated probe was (probably not…) called for. One scrap bin raid later, and I came up with a 7 component isolated probe that has several attributes: Isolated open-collector output to processor board Provides some wetting current ...
I am not sure that there is such a thing as a ‘safe’ way of recharging li-ion cells salvaged from discarded vapes – after all, they were made for disposable products, and all rechargeable lithium ion cells can get hot and even bust into flames when abused – and even famous manufacturers have made duff cells. My current risk-reducing strategy ...
Discarded vapes are not only an eyesore, and a sign that some vapers do not care about dropping litter, but are also a source of rechargeable Li-ion cells. Note for the uninitiated BEWARE: fire hazard, germ hazard and potentially harmful chemicals I picked up one just recently and it has a much neater internal construction (right). Gone is the rats ...
Prusa is a company that should be on the shortlist, may be at the top, for anyone buying a 3d printer for lab prototyping. The company emphasises print quality above print speed, but its printers are also fast, and it has a reputation for long-term support – it points out that its venerable Mk3 printer has been receiving updates for ...
Lady Ada, an exemplar of an entrepreneurial engineering if ever there was one, has demonstrated using OpenAI’s ChatGPT Canvas as a live AI design assistant. She creates a set-up library for Vishay’s VCNL4200 proximity and ambient light sensor , giving the data sheet to the AI in .pdf form so that it can look up parameters. See human and machine ...
