With the development of LEDs of multiple colors and increased brightness, they are currently being considered for many more lighting applications before. On problem with LEDs is that when connected in parallel they do not share current well. Since the brightness is directly dependant on current, this can cause uneven lighting effects. A common solution to the problem is to place resistors in series with the LEDs. This, however, causes considerable losses in the system. A proposed alternate approach is to supply the LEDs with a high frequency ac and control the current with series capacitors. Questions about the efficiency of this approach are questioned because of losses in the resonant circuit to create the high frequency ac.
This objective of this project would be to measure the efficiency of both methods. Circuits would be designed to create the equivalent brightness from the same source. Variations of the Q of the resonant circuit may be investigated to observe the effect on the overall circuit.
Knowing when cutting tools are wearing out is an important part of keeping modern manufacturing processes efficient. Direct measurements of tool wear require production to stop while measurements are made. This down time can cause a considerable loss in production efficiency.
A proposed alternative is to measure electrical quantities to indirectly indicate the current state of wear on a given cutting tool. Changes in the cutting ability of the tool would reflect itself in the electromagnetic torque developed in the machine. Such changes in the electromagnetic torque would be directly related to the changes in the instantaneous power flowing into the machine.
This project would be to measure the effect of worn tools on a simple system. This project proposes to use a small drill press as the cutting machine. Instantaneous measurements of current and voltage as a function of time will be made as the machine cuts into a know material. The instantaneous power will be calculated. Runs will be made at various conditions of tool wear to see if a correlation can be made between the power signature and the condition of the tool.