EEVblog 1384 - Halve Your Processor Power Consumption!

Halve Your Processor Power Consumption using Diffusion Capacitance!
Dave demonstrates a neat but tricky technique to PWM a processor's power pin to reduce power consumption.

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[thevaf]

Thanks Dave! That’s great! I’ll use this in the next heart pacing implant I design :D

[thunder]

Could this technique be used to improve the efficiency of the solar roadways? Maybe by using the vibrations caused by trucks shattering the glass...

[romsthe]

0% PWM gives 0% consumption 😲 there should be a Kickstarter campaign about that

[patrickweggler]

Damn every year you catch me off guard with you being ahead one day down under🤣

[mscir]

I was an electronics tech, we used reverse biased diodes called varactors to tune the frequency of oscillators, I worked on stuff from 400 MHz to 18 GHz or so. As you reverse bias the diode the depletion layer walls grow father apart and capacitance goes down, so frequency goes up. It worked quite well, we had varactors that tuned anywhere from 15V to 60V. Fr = 1 / 2 * PI * SQR(L * C) So yes there is absolutely capacitance in diodes.

[WizardTim]

Fun fact: this is actually how Intel’s ‘Fully Integrated Voltage Regulator’ works which allows them to get much better power efficiency and remove all inductors from the BOM. Sadly due to collusion with big power companies they only use this technology in their server CPUs, 4th gen desktop CPUs did have it but they were too efficient which affected their server CPU sales hence why the feature was removed. Unfortunately, you’ll never see this technology anywhere else because Intel has the exclusive patent on it (filed in 1951, expires in 2151). You can also PWM most nuclear power plants and get over unity from the fuel, this works by uranium enrichment capacitance between protons and negtons but the size of the required MOSFET is rather difficult to manufacture.

[Clough]

I'm not totally convinced this will work in practice, since the effect will be almost completely offset by capacitive diractance.

[MrNukKKT]

Thanks Dave! I love this bit of knowledge. We're implementing this in our next pacemaker, and we're now certain the device will outlive the patient.

[guilhermgonzaga]

The easiest way to spot this one was when Dave said "Hi, just a quick video", as always, but this time it actualy was.

[Zardox-The-Heretic-Slayer]

I assumed it was just one of your tricky videos but I had spare time, tried it and it actually worked

[satyamfifa]

Every year! I am watching EEVblog and thinking to myself hey something doesn't quite add up here, and then check the date, and then I am like there it is finally a rational non supernatual explanation

[Sahko]

These videos get better every year *cough* teaching us something new and interesting that we as students can *cough* carry on into our future designs.

[velox__]

Throw a batterizer and a WindWall generator into the mix and you're cooking!

[cowasakiElectronics]

Sinclair (Clive of Spectrum fame) used PWM to extend the life of the battery on his calculator back in the 80s :-)

[admirerofclassicalelectron]

Thanks a lot! Just modded my IBM System i (my primary business machine) with an arduino. Power consumption drops from 4.3 kW to 2.3 kW.

Great video! Solar panel roadways + battery savers should be added though for better result.

[joelmurphy]

What a great way to drop mcu power consumption! There's gotta be a jellybean part that will drop in and do this. Killer hack, Dave.

[cmuller]

Australia is always ahead of everyone...

[obdHsN]

It is very confusing to be watching this in the UK, with the date showing in the UK timezone :D

[martinda]

Clive Sinclair made his first calculators work by switching the power to the 'new' Texas calculator chip allowing a small pocket size battery device.