Examples of work

  High-power, high-speed piezo driver, version 1

The images below show the development of a high-power, high-speed driver for pulsing high-power piezos.

The instrument can supply up to 220V pulses at 400KHz. Both parameters are capable of being fine-tuned to hit the narrow ‘sweet spot’ of the target system. The pulses are modulated with a low frequency pulse chain. The low frequency has fine tuning capability as well as to give added control. This instrument pulses the power piezo which in turn forces a small vacuum chamber to oscillate up and down. The particles inside the chamber then bounce up and down allowing for the particle to be optically trapped and then the physics experiments begin. At the core of this system is a high end PIC32 microcontroller..

High-power, high-speed piezo driver, version 2

The original piezo driver, although a success, was much improved upon after a second instrument was requested.

The first design was very inefficient due to the design being based around single ended switch topology. This means that massive pulse energy was wasted. The second instrument was designed around half-bridge topology thus ensuring extremely high efficiency. This allowed for more functions to be added such as pulse-width modulation (PWM) of the fast high voltage pulses, which allowed for more tuning capability.

It also allowed for the instrument to be a fraction of the size and a fraction of the weight. To give an idea of this the high voltage storage capacitors in the first one were 16000μF, whereas in the second the were 1000μF. The transformer in the former was 8Kg, in the second it was 1Kg.

High-power LED colour light driver unit

This is an 256 bit RGB light chamber. A sample would be placed into the chamber and be exposed to a various wavelengths of high powered LED light. The user interface was designed to be intuitive.

Pump valve controller unit

This control system was deigned to prolong the life of vacuum pumps. This was achieved by switching on 5 pumps and 5 valves in a programmable timing sequence as opposed to the pumps being on all of the time. At the heart of this system was a high end PIC32 microcontroller which had the desired timing capabilities to accomplish the task.

Observatory

We have carried out a vast array of work at the observatory. This has ranged from designing control and drive units for the control of the ‘legendary’ Gregory telescope to designing dome control systems for the smaller domes. A lot of this work has been interesting, for example interfacing sixty year old electronics to modern designs. We continue to support Aleks regularly with electrical and electronic work.

Gas Detection System

 

20161212_145656_002     20161212_145726_003 20161212_145751

The above units were designed primarily for supporting a gas detection system. The electronics embedded in these units are aged as they were designed in 2006. For more information on this project please visit:

https://research-repository.st-andrews.ac.uk/handle/10023/731

DEVELOPMENT

20170118_123031With such an exponential rise in electronic technology it is very difficult to keep up to date with everything. We therefore try to learn as required when new projects arise. One such way to learn is the use of development boards as shown above. If any member of staff suggested it may be of good use to learn a particular skill we would give it consideration.