Abstract: A power converter circuit includes a switch including a field effect transistor, the field effect transistor being a wide bandgap field effect transistor and being configured to maintain an on operational state responsive to a maintenance signal received through a gate terminal, a current sensing circuit that is configured to estimate a drain terminal current of the field effect transistor responsive to a voltage between the gate terminal of the field effect transistor and a source terminal of the field effect transistor, and a gate driving circuit that is configured to generate the maintenance signal responsive to the estimate of the drain terminal current.

Abstract: A power converter circuit includes a switch including a field effect transistor, the field effect transistor being a wide bandgap field effect transistor and being configured to maintain an on operational state responsive to a maintenance signal received through a gate terminal, a current sensing circuit that is configured to estimate a drain terminal current of the field effect transistor responsive to a voltage between the gate terminal of the field effect transistor and a source terminal of the field effect transistor, and a gate driving circuit that is configured to generate the maintenance signal responsive to the estimate of the drain terminal current.

Abstract: A power converter circuit includes a switch including a field effect transistor, the field effect transistor being a wide bandgap field effect transistor and being configured to maintain an on operational state responsive to a maintenance signal received through a gate terminal, a current sensing circuit that is configured to estimate a drain terminal current of the field effect transistor responsive to a voltage between the gate terminal of the field effect transistor and a source terminal of the field effect transistor, and a gate driving circuit that is configured to generate the maintenance signal responsive to the estimate of the drain terminal current.

Abstract: A power converter circuit includes a switch including a field effect transistor, the field effect transistor being a wide bandgap field effect transistor and being configured to maintain an on operational state responsive to a maintenance signal received through a gate terminal, a current sensing circuit that is configured to estimate a drain terminal current of the field effect transistor responsive to a voltage between the gate terminal of the field effect transistor and a source terminal of the field effect transistor, and a gate driving circuit that is configured to generate the maintenance signal responsive to the estimate of the drain terminal current.

Abstract: A combustion driven, portable, HVAC duct cleaning system is provided wherein the components of the system are quickly and easily attachable and detachable and are mounted on cart means to allow for mobility of the system. The system includes ducting for attaching the system to ductwork to be cleaned, a primary filter for filtering large debris, a combustion driven blower for creating an airflow, and a secondary filter for final filtering of the air prior to release into the atmosphere. The primary filter includes a breach door for opening the filter to remove filtered material therefrom. The breach door may include a transparent panel for permitting one to view the interior thereof. Preferably, the primary filter includes a wire mesh cone, the point of which extends into the air flow to provide for the filtering of large objects. The blower is preferably a tube axial blower driven by means of a belt interconnected with a combustion engine for driving the impeller within the blower to create an airflow.

Abstract: This H.V.A.C. duct cleaning system comprises an air compressor connected to a manifold wherein at least one line is coupled to an air gun with a quick connect device while another line is connected to the duct cleaning system providing a pressurized exhaust to remove debris from the ducts. Fixed lengths of plastic tubing are connected to the air gun and one another by quick connects with the end tubing having an air head to dislodge dirt and other contaminants within the ducts. The duct cleaning system includes a series of filter and blower modules controlled by a variable frequency drive to convert and control power to the various blowers. A primary filter module is connected to the ducts, a main filter module connected to the outlet of the primary filter module or blower and a blower which preferably is a tube axial blower or can be a backwardly inclined centrifugal blower is connected to the outlet of either the primary or main filter module to provide a pressurized exhaust.

Abstract: This H.V.A.C. duct cleaning system comprises an air compressor connected to a manifold wherein at least one line is coupled to an air gun with a quick connect device while another line is connected to the duct cleaning system providing a pressurized exhaust to remove debris from the ducts. Fixed lengths of plastic tubing are connected to the air gun and one another by quick connects with the end tubing having an air head to dislodge dirt and other contaminants within the ducts. The duct cleaning system includes a series of filter and blower modules controlled by a variable frequency drive to convert and control power to the various blowers. A primary filter module is connected to the ducts, a main filter module connected to the outlet of the primary filter module or blower and a blower which preferably is a tube axial blower or can be a backwardly inclined centrifugal blower is connected o the outlet of either the primary or main filter module to provide a pressurized exhaust.

Abstract: An apparatus for locating a camper on a pick-up truck bed comprises a pair of members securable to the truck bed and the camper. A first member has an opening for receiving a portion of a second member as the camper is lowered towards the bed. The opening is substantially larger than the portion of the second member so that the second member is readily locatable within the opening. The members have a tapering fit therebetween and fit closely together when the camper is lowered onto the truck bed so the camper is properly located thereon.