A scroll wheel assembly for computer input device having a housing. The phosphor comprises a compound of the formula MgxCa1-xAl2S4:M, where the value of x is in the range 0<x<0. According to another aspect of the techniques, a dynamic alternating electric field bonding is provided to eliminate bubbles from a type of glue used to bond two substrates, wherein a power source is used to generate a dynamic alternating electromagnetic field in accordance with the substrates andor the characteristics of the glue. The safety guidewire allows the access needle and the intravenous catheter to be safely advanced into the vein. A virtual port is electrically connected to the DMA unit and the processor. The drive control circuit utilizes the sensor outputs of the n magnetic sensors to generates n sets of drive signals for the n phase magnet coil groups.