Engineer In Wonderland

Having made a few guitar effects in my time, but not being musical, I am always interested in what makes different effects tick. So imagine my delight when I came across ElectroSmash, a website devoted to such things. Classic circuit are reverese-engineered and described, and the people behind the website have  also designed and published their own effects, including some ...

I had cause to have a closer look at some Arduino inputs – it is that fascinating weather station again. It transpires that some Arduino inputs are better at tolerating slowly-changing inputs than others. For example, ATmega328P (Figure 13-2, Arduino Uno and Nano) and ATmega32U4 (Figure 10-2, Arduino Leonardo, Micro or Pro Micro) Arduinos have hysteresis built into the input side ...

Inspired by a conversation with Mr Kurt of this parish, I set out to add to my zero knowledge in the dc interconnectors that ferry gigawatts around the planet. ABB (Siemens seem to be significant as well, plus Toshiba and others) has a nice summary of of its HVDC Light system, from which I gleaned that it uses six IGBT assemblies ...

Certain Microchip (was Atmel) ATtiny and ATmega microcontrollers have a handy phase-locked loop which boosts the 16MHz clock up to 64MHz for peripherals including the PWM. May 2022 update – tinyAVR 1-series – below These tend to have a dead-band generator to provide a pair of non-overlapping but anti-phase PWM signals to drive a half-bridge power stage – the dead-band ...

Timer4 on the ATmega32U4 (Arduino Leonardo, Micro, Pro Micro) is another one of Microchip/Atmel’s high-speed timers that can be fed by a PLL (phase-locked-loop) multiplied version of the 16MHz system clock – up to 64MHz in this case. Here are some ATtiny’s with similar timers. Now, there are plenty of cheaper Arm Cortex-M..-based microcontrollers with even higher PWM clock speeds ...

I was pondering with a friend last night, do we need new nuclear. And the answer seems to be yes, unless folk can adapt their consumption around the wind, sun and tides – which is possible, but the fact many people can’t be bothered to even spend five minutes sorting their recycling suggests that some percentage of the population will ...

My mind got boggled again yesterday – someone had found a mineral enclosed in a diamond that bought it up from the Earth’s lower mantle – amazing. I just looked it up – the mineral was our new friend a perovskite – in this case calcium silicate (CaSiO3) and not the Pb-halide type appearing in solar cells. Carried in that crystal structure ...

Rather than shout at the radio again, I produced a handy infographic* I am sure it doesn’t apply to all politicians** For those that it does apply to (and can still learn), I once again recommend the totally brilliant ‘Twenty tips for interpreting scientific claims‘, published by Nature. It is written by Biologist Professor William Sutherland (University of Cambridge), Statistician ...

TI’s LM74670-Q1 is a controller that, combined with an n-channel mosfet, makes a diode with a forward drop of 20mV 98% of the time. It only connects to the mosfet (and a capacitor) and not to any nominal voltage rails, so four of them can be turned into a low-drop bridge rectifier that TI claims will work up to 300Hz, ...

Greenwash is pouring into the inbox, sloshing along with the rest of the COP26 bandwagon jumpers, and in such quantity that I cannot sort the wheat from the chaff. So instead, I am going to mention sulphur hexaflouride, beloved for its dielectric strength in high-voltage switch-gear. By definition, CO2 has a global warming potential of one, then other compounds are ...