Abstract: An in-line device for controlling a ventilation system for an enclosed space is featured. The ventilation system is configured to produce a first airflow from an external environment to the enclosed space and a second airflow from the enclosed space to the external environment. The in-line device includes a first electrical interface configured to connect to an electrical outlet, a second electrical interface configured to receive a power plug for the ventilation system, and a controller configured to control the ventilation system based on a first parameter of the first airflow and a second parameter of the second airflow.

Abstract: A method of providing ventilation for an enclosed space includes detecting, by a controller including one or more processing devices, an operation of a door to the enclosed space in response to receiving a first signal indicative of an electrical characteristic of a motor that operates the door to the enclosed space. The method further includes generating, by the controller responsive to detecting the operation of the door, a control signal configured to operate a ventilation system to exhaust air from within the enclosed space to an environment outside of the enclosed space. The method also includes transmitting the control signal to cause an activation of the ventilation system.

Abstract: A method of ventilation includes receiving at least one signal indicative of an operation of one or more exhaust fans causing air to be exhausted out of a building. The method further includes determining, by one or more processing devices, a total expulsion rate of air being exhausted out of the building by the one or more exhaust fans based on the signal, and determining, by the one or more processing devices, a target fan speed of one or more intake fans configured to draw external air into the building. The target fan speed of the one or more intake fans is determined to achieve an inflow rate that is substantially equal to the total expulsion rate. The method also includes controlling the one or more intake fans using one or more control signals in accordance with the target fan speed.

Abstract: A method of providing ventilation for an enclosed space includes detecting, by a controller including one or more processing devices, an operation of a door to the enclosed space in response to receiving a first signal indicative of an electrical characteristic of a motor that operates the door to the enclosed space. The method further includes generating, by the controller responsive to detecting the operation of the door, a control signal configured to operate a ventilation system to exhaust air from within the enclosed space to an environment outside of the enclosed space. The method also includes transmitting the control signal to cause an activation of the ventilation system.

Abstract: A hybrid ground penetrating radar (GPR)/metal detector (MD) head includes a V-dipole GPR antenna and transmit and receive MD coils. One of the MD coils is arranged in a quadrupole configuration with a crossbar, and the V-dipole antenna is perpendicular to the crossbar. The legs of the V-dipole antenna may straddle the crossbar or may be on one side of the crossbar. The MD coils may be fabricated on a printed circuit board, which may be at a non-normal angle with respect to a central axis of the V-dipole antenna.

Abstract: This application describes methods and systems for ventilating a building. A method for ventilating a building includes drawing in air, using a central fan, for heating or cooling at least a portion of the building and exhausting air from the building using at least one exhaust fan. The exhaust fan can be automatically operated during time periods when the central fan is not switched on.

Abstract: An amount of time that air has been delivered from an air handler to a space is tracked, and based on the tracked amount of time, at least one turn-on time or one turn-off time of the delivery of air from the air handler to the space is controlled. Other features relate, among other things, to controlling a replacement air vent, and to user interfaces.

Abstract: A hybrid ground penetrating radar (GPR)/metal detector (MD) head includes a V-dipole GPR antenna and transmit and receive MD coils. One of the MD coils is arranged in a quadrupole configuration with a crossbar, and the V-dipole antenna is perpendicular to the crossbar. The legs of the V-dipole antenna may straddle the crossbar or may be on one side of the crossbar. The MD coils may be fabricated on a printed circuit board, which may be at a non-normal angle with respect to a central axis of the V-dipole antenna.

Abstract: Methods of generating a write current in response to a write command include generating a reverse preshoot write current having a polarity opposite to a polarity for generating a magnetic transition corresponding to the write command, and then generating a write current to effect the magnetic transition corresponding to the write command. The write current may be used for writing data to a storage disk of a disk drive that includes a write head configured to apply a magnetic field to the storage disk responsive to write currents. A preamplifier circuit includes a write current generator configured to receive a write current command and configured to generate, responsive to the write current command, a reverse preshoot current having a first polarity that is opposite a second polarity for generating a magnetic transition corresponding to the write command.

Abstract: A method for controlling a fan and a light. A ventilation time period length is established. During a predetermined period of time: (i) the light is operated in response to a user placing a controller in a first state; (ii) the fan is operated during a first period of time corresponding to the time when the light is in operation, in response to the controller being placed in the first state; (iii) operation of the light is discontinued in response to the controller entering a second state; (iv) operation of the fan is discontinued in response to the controller entering the second state; and (v) the fan is automatically operated for a second period of time in addition to said first period of time, when the light is not in operation, such that the fan is operational for a total period of time having at least the ventilation time period length.

Abstract: An amount of time that air has been delivered from an air handler to a space is tracked, and based on the tracked amount of time, at least one turn-on time or one turn-off time of the delivery of air from the air handler to the space is controlled. Other features relate, among other things, to controlling a replacement air vent, and to user interfaces.

Abstract: A method for preventing electrical overstress from interfering with a magnetic read-write device by identifying one or more characteristic functions of the device that characterize electrical overstress, generating a wave form representative of the electrical overstress by using the one or more characteristic functions and enabling the generated wave form to be combined with a read signal to counteract the electrical overstress. The method can be implemented with a crosstalk cancellation circuit that includes a coupler filter configured to receive signals from the write driver, a differentiator to differentiate the signal, a gain adjust coupled to the coupler filter configured to adjust gain on the received signal, a phase adjust configured to adjust the phase to match the crosstalk, and an inverter coupled to invert the matched signal to enable cancellation of the crosstalk.

Abstract: An amount of time that air has been delivered from an air handler to a space is tracked, and based on the tracked amount of time, at least one turn-on time or one turn-off time of the delivery of air from the air handler to the space is controlled. Other features relate, among other things, to controlling a replacement air vent, and to user interfaces.

Abstract: Methods of generating a write current in response to a write command include generating a reverse preshoot write current having a polarity opposite to a polarity for generating a magnetic transition corresponding to the write command, and then generating a write current to effect the magnetic transition corresponding to the write command. The write current may be used for writing data to a storage disk of a disk drive that includes a write head configured to apply a magnetic field to the storage disk responsive to write currents. A preamplifier circuit includes a write current generator configured to receive a write current command and configured to generate, responsive to the write current command, a reverse preshoot current having a first polarity that is opposite a second polarity for generating a magnetic transition corresponding to the write command.

Abstract: An amount of time that air has been delivered from an air handler to a space is tracked, and based on the tracked amount of time, at least one turn-on time or one turn-off time of the delivery of air from the air handler to the space is controlled. Other features relate, among other things, to controlling a replacement air vent, and to user interfaces.

Abstract: An amount of time that air has been delivered from an air handler to a space is tracked, and based on the tracked amount of time, at least one turn-on time or one turn-off time of the delivery of air from the air handler to the space is controlled. Other features relate, among other things, to controlling a replacement air vent, and to user interfaces.

Abstract: An amount of time that air has been delivered from an air handler to a space is tracked, and based on the tracked amount of time, at least one turn-on time or one turn-off time of the delivery of air from the air handler to the space is controlled. Other features relate, among other things, to controlling a replacement air vent, and to user interfaces.

Abstract: An amount of time that air has been delivered from an air handler to a space is tracked, and based on the tracked amount of time, at least one turn-on time or one turn-off time of the delivery of air from the air handler to the space is controlled. Other features relate, among other things, to controlling a replacement air vent, and to user interfaces.

Abstract: An amount of time that air has been delivered from an air handler to a space is tracked, and based on the tracked amount of time, at least one turn-on time or one turn-off time of the delivery of air from the air handler to the space is controlled. Other features relate, among other things, to controlling a replacement air vent, and to user interfaces.

Abstract: An amount of time that air has been delivered from an air handler to a space is tracked, and based on the tracked amount of time, at least one turn-on time or one turn-off time of the delivery of air from the air handler to the space is controlled. Other features relate, among other things, to controlling a replacement air vent, and to user interfaces.