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Dr David Gibson

Recent Publications

This page lists some of my more recent publications. Unfortunately, I cannot add them to the university's list because  an honorary appointment does not confer access to Symplectic. So, here are some recent notes from the CREG journal. Click on the "CREGJ" links to go to the CREG Journal web site.

Update: Pressurised Enclosures, CREGJ 113, p12. March 2021

As a follow-up to his notes on building rugged equipment, David Gibson further describes the use of a pressurised enclosure to prevent moisture ingress.  

Energy Harvesting with Electrets, CREGJ 113, p16. March 2021

David Gibson envisages a portable energy-harvesting device utilising a wristwatch-style automatic winder, with the mainspring driving an electrical power generator that uses an electret material. The mainspring provides a method of regulating the power transfer, not unlike the concept of 'power matching'.  

Update: Regenerative Brake, CREGJ 112, p21. December 2020

In an extension of his notes on regenerative braking, David Gibson describes how to build an LED lamp that is powered by a falling weight.  

The Parallel-Fed Voltage Multiplier, CREGJ 111, pp10-12,22. September 2020

Voltage doublers and the Cockcroft-Walton voltage multiplier are examples of devices that use capacitors as charge-pumps to generate a high voltage at a low power in a relatively simple circuit. The conventional voltage multiplier is series-fed, acting as a 'bucket brigade' to pass the charge from one element to the next. This is difficult to analyse, as well as being inefficient, with a law of diminishing returns applying. A better scheme is the less well-known parallel-fed device, which has several advantages. David Gibson analyses this device, arguing that it deserves to be better known, and suggests some possible cave electronics applications.  

The Mystery of the Missing Energy, CREGJ 111, pp20-22. September 2020 

Whenever a capacitor is charged, energy seems to go missing. This has consequences when designing equipment that makes use of capacitor charging, such as a charge pump. David Gibson explains the phenomenon and challenges the reader to say where the supposedly missing energy might have gone.  

Regenerative Brake Charges Your Caving Lamp Whilst You Abseil, CREGJ 110, pp13-16. June 2020    

A caver abseiling down a pitch will lose potential energy, which is converted into heat in his abseiling device; but what if it were converted into useable energy instead? David Gibson explains the principles behind regenerative braking and how you might use the braking energy to charge a battery. However, this is for theoretical interest only, and definitely not something to try out in practice!