All posts by Rhys

moellerWithin a PLC course, as an introduction, I was required to develop an application for the “Moeller EasySoft PLC”, a rudimentary PLC when compared to current industrial standards. During code development, PLC programming techniques and standards had not been taught beyond the mechanics of ladder logic processing, latching and memory use.
This application was widely recognised as the best in the class and the only project to fail-safe on controller power loss, attempt to recover from an error and to have verbose error diagnostics.

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5.Action_ShotWarning: Incomplete write-up.
Server Side:
Image –> Resize to 16px height –> Determine Pixel Red, Green and Blue components –> Compensate, arrange and bit-shift values to a byte string of 12 bit PWM (Pulse Width Modulation) values.

Use hall effect sensor for positioning –> Display RGB PWM image using internal microcontroller timers and serial communication.

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20150720_230617Need a cheap high current power supply?

Use an old (or new since they can be pretty cheap) computer power supply as a bench top power supply rated for | 17A @ 12V || 38A @ 5V || 28A @ 3.3V || 0.5A @ -12V |

To turn an ATX power supply on, look for a thin green wire on the main connector, if you short this wire to ground (black) it will turn the power supply on until you remove the short. The power supply should identify the voltage and current rating of each coloured wire as the one I used does, but if not then the voltages should just a multimeter away and the current ratings should be readily available if you look up the relevant power supply’s specifications.

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Principles of Electronic Instrumentation assessment project, 22% of unit mark.

The brief was to detect if an object passing through two sensors is exceeding a given speed using any of a mandated list of components with minimal power consumption. The of permissible components included infrared LEDs, photo-diodes, NPN BJTs (transistors), 555 timers as well as a selection of resistors and capacitors.
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Principles of Electronic Instrumentation assessment project, 10% of unit mark.

Paraphrased project brief: become familiar with Multi-vibrators and Bipolar Junction Transistors to design a Schmitt trigger to meet the given specifications.

The context given is that a degraded signal was being received by a photo diode (modelled as a current source) and needed to be cleaned up by a Schmitt Trigger utilising hysteresis.

Supply voltage an trigger points were specified by the facilitator. Continue Reading