Mark Ravelle

Mark Ravelle Director Silicon Wold Ltd.

Mark Ravelle Director Silicon Wold Ltd.

ELECTRONICS Research and Development

My main focus is on R&D. I develop prototypes and computer simulations for clients who want to experiment with novel processes, products or applications. My skills are in the field of applying electronics to physics applications, instrumentation and mechatronics. I dabble with DSP filters and FFTs, MCUs, CPUs and CPLDs.

I began my career in high-end image processing, working on both software and electronics. Later on, I started specialising more on the electronics side, but these days, with the advent of very high spec but affordable MCUs, I tend to do a lot of embedded work, which is a happy fusion of hardware and software. USB connectivity is included on all but the cheapest MCUs, which means that the embedded system is often only used as a front-end board, with the bulk of the processing happening on the attached PC.

One of the free tools that has helped me immensely in recent years is LTspice. This is a circuit simulator derived from Berkeley’s SPICE simulator, that lets one simulate all manor of electronic circuits, and has a large library of LT’s own parts. These days, I seldom breadboard anything before running a SPICE model to fine-tune the analogue front end. Of course I have ended up specifying more LT parts than I otherwise would, but given that the simulator gives me a good idea of what to expect, I certainly don’t begrudge them the business. Simulation is becoming a very important part of the consultancy process these days, as it can weed out schemes that seem a good idea in theory but can never be made to work reliably in practice.

Recent projects include:

  • Numerous types of laser power supply
  • Photo-acoustic techniques
  • PID Controllers (Proportional Integral Derivative controller) for thermally tunable lasers
  • High-Power (125watt) water cooled LED array driving
  • SONAR in air
  • FFT and IFFT for real numbers, written from scratch. (Very fast, IP owned outright)
  • Embedded system for gas spectrometer, using software lock-in
  • Microstepping of all sizes of stepper motor. Achieved +/- 2 micron accuracy in spectrometer application.

Current Research:

  • MPC (Model Predictive Controller) I am working on a novel technique using fractional Fourier Transforms to analyse multidimensional control systems. Looking for a commercial plant holder to partner with me who is interested in creating the next generation of Model Predictive Controllers.
  • Satellite thruster technology. Research into electromagnetic thrusting for geostationary and near earth satellites.

Contact me on +44 7974 001907