A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series.
An LED driver is the power supply for an LED system, much like a ballast is to a fluorescent or HID lighting system, says Al Marble, manager - sales & market development for Philips-Advance Transformer.
Filter drivers are optional drivers that add value to or modify the behavior of a device. A filter driver can service one or more devices. Bus Filter Drivers. Bus filter drivers typically add value to a bus and are supplied by Microsoft or a system OEM (see the Possible Driver Layers figure). Bus filter drivers are optional. There can be any number of bus filter drivers for a bus. A bus filter driver could, for example, implement proprietary enhancements to standard bus hardware. For devices described by an ACPI BIOS, the power manager inserts a Microsoft-supplied ACPI filter (bus filter driver) above the bus driver for each such device.