Engineer In Wonderland

TI updated the LM339 family of comparators a few years ago, when it moved them from a 150mm wafer manufacturing process to 300mm high-voltage junction-isolated process. These comparators, which come in quad, dual and single versions, were initially released 50 years ago with such a good design – they were the first ‘single-rail’ types which included the 0V rail in ...

The LM334 is not only an adjustable current source, but it is also a rectifier. Right on the front page of the TI data sheet are the words: “Reverse applied voltages of up to 20V will draw only a few dozen microamperes of current, allowing the devices to act as both a rectifier and current source in AC applications.” Which ...

Oh what a delight when an interesting email drops randomly into the inbox. Apparently, Mammoet is assembling the world’s biggest land-based crane at Westdorpe in the Netherlands even as I type. SK6000 is a ‘ring crane’, sitting on a circular track, and able lift huge weights around over large areas – and it looks like separating the counterweight allows for ...

Shenzhen MilkV Technology has a chip that combines: 1x 1GHz C906 RISC-V CPU 1x 700MHz C906 RISC-V CPU 1x 1GHz Arm Cortex-A53 CPU 1x 8051 CPU 1x 1Top/s (INT8) neural processor Called SG2002, it also has 256M (byte, probably…) DRAM, a camera interface, video acceleration, an audio codec and a crypto engine. Peripherals include 100Mbit/s Ethernet (with a phy), USB 2.0, ...

I was out in the countryside with a partially-obedient dog over the weekend. It spontaneously bolts off, the owner told me, for up to a couple of hours. Why not use a dog tracker? I asked naively. It has one, said the owner, but the tracker does not work without mobile phone coverage – when you get home, you know ...

A few years ago, a friend of mine was trying to build a solar-powered device to automatically photograph the sun in the sky at exactly noon every day through a whole year – the aim, purely for interest, was to create an analemma photograph showing the figure-of-eight that the sun follows as the months progress. At the time, getting a ...

All credit to Thomas Langewouters for an unusual reed switch ladder circuit for liquid level sensing. You can find it on his website here. He went on to use a more traditional two-terminal design, but this four-terminal circuit, as he points out, can be used to get a little more information. Fluid level sensing with reed switches involves a fixed ...

It is spring time, so it must be time to contemplate once more the many challenges of Cuk converters. And this time it is the question: how does one turn on and off a load when the output of a Cuk converter is of the opposite polarity to the input (right). The obvious thing is to hang a p-channel mosfet ...

One of the monomaina’s in Wonderland is ‘building a better pulse generator’, for want of a better phrase. It should be so easy with all the Arduino-esk microcontroller boards out there that have lovely timers inside, but a recurrent drawback is that it is hard to find one that runs at a ‘nice’ frequency – one with a clock period ...

I had no idea that it was possible to buy people-detecting radar modules for under 10 quid, but you can. There is a bunch of different models, all doing roughly the same thing in the same way: detecting moving people and other conductive objects up to a few metres away – RCWL-0516 is an example. In behaviour, they are much ...