Abstract: A method of operating a turbocharged engine having cylinders in which one of the cylinders undergoes a compression stroke. The method includes advancing an ignition spark in the one of the cylinders undergoing the compression stroke by a first amount relative to top dead center of the compression stroke at a first barometric pressure for a given engine speed and load, and advancing the ignition spark in the one of the cylinders undergoing the compression stroke by a second, lesser amount relative to top dead center of the compression stroke at a second, lower barometric pressure, for the given engine speed and load as the vehicle being at different altitudes.

Abstract: A method for switching between low- and high-dilution combustion modes in an internal combustion engine having an intake passage with an exhaust-driven turbocharger, a crankshaft-driven positive displacement supercharger downstream of the turbocharger and having variable boost controllable with a supercharger bypass valve, and a throttle valve downstream of the supercharger. The current combustion mode and mass air flow are determined. A switch to the target combustion mode is commanded when an operating condition falls within a range of predetermined operating conditions. A target mass air flow to achieve a target air-fuel ratio corresponding to the current operating condition and the target combustion mode is determined. The degree of opening of the supercharger bypass valve and the throttle valve are controlled to achieve the target mass air flow. The amount of residual exhaust gas is manipulated.

Abstract: An engine includes a variable geometry turbocharger, an EGR valve device, a hydraulic servo drive device that drives the variable geometry turbocharger, a hydraulic servo drive device that drives the EGR valve device, an electronic proportional control valve (EPC valve) that supplies pilot pressure oil to the hydraulic servo drive device, and an electronic proportional control valve (EPC valve) that supplies pilot pressure oil to the hydraulic servo drive device, the EPC valves being attached to the EGR valve device.

Abstract: An internal combustion engine is disclosed, comprising at least one first compression device and at least one second compression device which is connected in series relative to the first compression device. At least one bypass pipe bypasses at least one compression device. At least one controllable valve is arranged in the at least one bypass pipe such that the amount of fluid which can be recirculated around the compression device can be controlled.

Abstract: A turbine assembly for an exhaust gas turbocharger has separate first and second volutes that are sequentially activated via a valve that receives exhaust gases from an engine. In a first position of the valve, only the first volute receives exhaust gas; in a second position, both volutes receive exhaust gases. In a third position, a bypass passage is also opened so that some exhaust gas bypasses the turbine wheel. Unlike conventional twin-scroll turbines, each volute receives exhaust gases from all engine cylinders, and the first volute feeds gas into the B-width portion of the wheel, while the second volute feeds gas into the wheel after the contour portion.

Abstract: A method of operating a variable geometry turbine (VTG) during transient operations for maximum response by determining the VTG area at the balance condition of the pressure ratio and efficiency curves for the variable geometry turbine to achieve maximum power. The method includes measurements of turbine inlet pressure, turbine outlet pressure, turbine rpm, and other parameters used to measure turbine mass flow.

Abstract: In one exemplary embodiment of the invention, an internal combustion engine includes a turbocharger configured to receive an air flow and a first exhaust flow from the internal combustion engine and a supercharger downstream of the turbocharger configured to receive a compressed air charge from the turbocharger. The engine further includes an exhaust gas recirculation circuit receiving a second exhaust flow from the internal combustion engine and supplying the second exhaust flow to the compressed air charge upstream of the supercharger, wherein the second exhaust flow and compressed air charge comprise an exhaust-air mixed flow received by the internal combustion engine.

Abstract: In a charging device for an internal combustion engine, the charging device has at least one first line for the intake of fresh air, having at least one air-gap-insulated exhaust-carrying component. This is assigned to an outlet side of the internal combustion engine. At least one regulating element for distributing an exhaust gas stream, and at least one regulating element for distributing a pre-compressed fresh air stream is provided. The air-gap insulated exhaust-carrying component has an outer chamber, through which a controllable stream of fresh air flows.

Abstract: A method for providing intake air to an engine in a vehicle includes forming a mixture of fresh air and treated exhaust, and compressing the mixture upstream of a first throttle valve coupled to an intake manifold of the engine. The method further includes, during a higher engine-load condition, admitting the mixture to the intake manifold via the first throttle valve, and, during a lower engine-load condition, admitting fresh air to the intake manifold via a second throttle valve.

Abstract: A control and regulation method is described for a turbocharged internal combustion engine, in which in a high-performance range (HLB) the turbocharged air is pre-compressed via a two-stage turbocharging process. The described method comprises a low-pressure stage and a high-pressure stage and fed to the internal combustion engine and in which in a low-performance range (NLB) the turbocharged air, pre-compressed via the two-stage turbocharging process, is fed to the internal combustion engine, post-compressed via a compressor as a third turbocharging stage.

Abstract: In one aspect of the present disclosure, an exhaust emission reduction system is provided for an internal combustion engine. The engine receives an air stream for combustion with fuel in the engine and also generates an engine exhaust steam. The system includes a filter assembly having one or more exhaust emission reduction elements configured to process the exhaust stream, a performance of at least one of the one or more exhaust emission reduction elements being temperature dependent. The system also includes an apparatus for changing the temperature of the exhaust stream incident on the filter assembly. The system further includes a controller operatively connected to the apparatus, and adapted to regulate the temperature of the exhaust stream incident on the filter assembly based on the temperature of the exhaust stream.

Abstract: A method and system to control an engine to maintain turbine inlet temperature utilizes two temperature thresholds: a control initiation temperature and a maximum hardware temperature. An engine parameter is adjusted in a closed-loop manner based on an error, which is a difference between a setpoint temperature and the turbine inlet temperature. The setpoint temperature is initially the control initiation temperature. However, after control over turbine inlet temperature is established, the setpoint temperature ramps gradually to maximum hardware temperature. In one embodiment, the engine parameter is engine torque. Other engine parameters affecting turbine inlet temperature include timing and duration of fuel injection pulses, EGR rate, gear selection, and intake throttle position, any of which can be used in place of, or in combination with, torque for controlling turbine inlet temperature.

Abstract: In an internal combustion engine comprising an exhaust gas turbocharger, which includes a compressor with a compressor wheel arranged in an inlet tract of the internal combustion engine and a turbine with a turbine wheel coupled rotationally to the compressor wheel and arranged in an at least two-path exhaust gas tract of which is connected to an exhaust gas guide section of the turbine including at least a first spiral channel coupled to the first exhaust path and a second spiral channel coupled to a second exhaust gas path, two guide vane elements are arranged upstream of the turbine wheel and downstream of respective spiral channels which are formed corresponding to a first degree of asymmetry A1 determined as a quotient ? of a first mass flow parameter and a second mass flow parameter which is between 0.4 and 0.8.

Abstract: A method for preventing a surge event prior to a first surge event occurring in an engine system including a turbocharger and a diesel engine operable at a plurality of discrete speeds, the method comprising sensing an operating parameter of the engine system that determines a surge margin, determining whether a change in the sensed operating parameter may result in exceeding the surge margin, and controlling an operating input to the engine system to prevent the surge event from occurring.

Abstract: A cylinder of an internal combustion engine is provided with a turbo-side exhaust valve that opens and closes an exhaust port that communicates with a turbo-side exhaust passageway that leads to a turbine inlet opening of a turbo-supercharger, a bypass-side exhaust valve that opens and closes an exhaust port that communicates with a bypass-side exhaust passageway that bypasses the turbine, a first intake valve disposed opposite to the turbo-side exhaust valve, and a second intake valve disposed opposite to the bypass-side exhaust valve. At the time of engine startup and/or the time of low engine load, the turbo-side exhaust valve and the first intake valve are stopped in the closed state.

Abstract: A method to operate an electronically controlled internal combustion engine having an electronic central unit with memory a turbocharger and exhaust gas recirculation valve to determine performance characteristics of said variable geometric turbocharger.

Abstract: A method of controlling a turbocharger for an engine and a control system for the same includes a variable nozzle turbine control module operating a variable nozzle turbine of a high pressure turbocharger closed loop in a first load-engine speed region. The system also includes a high pressure turbine bypass valve control module operating a high pressure turbine bypass valve in a closed position in a first load-engine speed region. The variable nozzle turbine control module operates a variable nozzle turbine closed loop in a second load-engine speed region between the first load-speed region and a third load speed region. The high pressure turbine bypass valve module operates the high pressure turbine bypass valve in a transient region in the second load-engine speed region. The variable nozzle turbine control module operates the variable nozzle turbine open loop.

Abstract: A method for responding to an existing or incipient surge condition of a turbocharger coupled to an engine of a motor vehicle is provided. The method comprises receiving a signal responsive to an operating condition of the turbocharger and adjusting one or more operating parameters of the motor vehicle when a power of the signal, integrated over a pre-selected range of non-zero frequencies, exceeds a pre-selected threshold. Other embodiments provide related systems for responding to an existing or incipient surge condition of a turbocharger.

Abstract: Otto intake-cycle controlled-air (throttled) internal combustion engines suffer from parasitic pumping losses associated with partial vacuums developed in their intake manifolds and in the cylinders above their pistons. To solve this problem, there is provided individually partitioned dry-sump crankcases dynamic pneumatic coupling pressure reduction cycle system and method that reduce the damaging parasitic effects of the differential pressure about a piston head during an intake cycle which is a source of part-load pumping-loss friction. This closed loop system includes an independent supplemental mechanical fail-safe system of a turbo-compound engine variant for pneumatic coupling of individual cylinder-crankcase volumes. It does not alter the cylinder homogeneous mixture charge integrity and stability. The system is applicable to several engine configurations, such as controlled air intake or uncontrolled air intake combustion engines, using different fuel types, either in liquid or in gazeous state.

Abstract: A supercharging system for an internal combustion engine comprising a turbocharger including a compressor and a turbine, and a pressure wave supercharger performing supercharging of the internal combustion engine by increasing a pressure of gas led into each of cells from an intake gas inlet port using a pressure wave of exhaust gas led into the cell from an exhaust gas inlet port and discharging from an intake gas outlet port to an intake passage the gas pressurized, wherein a case of the pressure wave supercharger is connected to the intake passage upstream of the compressor via the intake gas inlet port, and is connected to the intake passage downstream of the compressor via the intake gas outlet port, and is connected to an exhaust passage downstream of the turbine via the exhaust gas inlet port and an exhaust gas outlet port.

Abstract: A turbocharger system for an air-throttled engine includes a variable flow expander (VFE) in the intake air conduit system that supplies intake air to the engine. At part-load operation, the VFE expands the air by an amount that is controllable, and thus regulates the air flow as needed by the engine. The power extracted by the VFE from the intake air flow is fed to the turbocharger, which helps to achieve quicker turbocharger response and improve scavenging of exhaust gases from the engine. The VFE can be a variable expansion ratio turbine.

Abstract: Simultaneous or independent control of a by-pass valve and a variable-geometry forced induction component on a combustion engine is based on operational parameters measured by various sensors provided as inputs to a control module. Sudden loss of power due to low turbine efficiencies is prevented during transitions between operating conditions of engine speed and load. Excessive peak cylinder pressures are also prevented by controlling engine boost pressure to a permitted limit at high engine speed and load.

Abstract: A method of controlling turbine efficiency in a turbo unit provided on an internal combustion engine includes providing a flow of gas in an area upstream a turbine at a direction different to the flow of exhaust gases in the same area, regulating the flow by a valve, and controlling the valve from a control unit having at least boost pressure and/or EGR flow as input parameters.

Abstract: A supercharging system (40) is disclosed which comprises a supercharging device (28) having at least one inlet port (42) and at least one outlet port (44), and at least one idle valve (30) in fluid communication with the supercharging device (28). The idle valve (30) is disposed adjacent the outlet port (44) and is arranged to selectively restrict fluid flow during use in a direction through the idle valve (30) towards the supercharging device (28). A corresponding supercharging kit and an internal combustion engine including a supercharging system are also disclosed.

Abstract: Disclosed is a super-turbocharger system that increases power and efficiency of an engine. The system uses the exothermic properties of a catalytic converter to extract additional energy from exhaust heat that is used to add power to the engine. Compressed air is supplied and mixed with exhaust gases upstream and/or downstream from a catalytic converter that is connected to an exhaust manifold. The gaseous mixture of exhaust gases and compressed air is sufficiently rich in oxygen to oxidize hydrocarbons and carbon monoxide in the catalytic converter, which adds heat to the gaseous mixture. In addition, a sufficient amount of compressed air is supplied to the exhaust gases to maintain the temperature of the gaseous mixture at a substantially optimal temperature level. The gaseous mixture is applied to the turbine of the super-turbocharger, which increases the output of said super-turbocharger, which increases the power and efficiency of said engine.

Abstract: A method is provided for reducing turbolag in a turbocharged internal combustion engine including an inlet manifold, an exhaust manifold, an exhaust gas recirculation (EGR) valve and a Variable Geometry Turbine (VGT) turbo unit. The method includes demanding torque for shifting the internal combustion engine from a stationary engine mode to a transient engine mode, closing the EGR valve during the transient engine mode, repositioning guide vanes of the VGT turbo unit from a first position when in the stationary engine mode to a second position when in the transient engine mode, increasing a duration of overlapping of at least one inlet valve and at least one outlet valve provided in a cylinder head of the internal combustion engine from a first duration when in the stationary mode to a second duration when in the transient mode for increasing the amount of air flowing from the inlet manifold to the exhaust manifold and thereby increasing acceleration of a turbine of the VGT turbo unit.

Abstract: An intake air flow rate detection device for an internal combustion engine (100), including a sensor (61, 63) that detects an operating condition of the internal combustion engine (100), an air flow meter (21) that disposed in the intake passage (20) upstream of the supercharging device (41), and a programmable controller (60) programmed to calculate a measured intake air flow rate from a detection value of the air flow meter (21), calculate a calculated intake air flow rate from the operating condition of the internal combustion engine (100), and employ either the measured intake air flow rate or the calculated intake air flow rate as an intake air flow rate of the intake passage (20) on the basis of an air flow rate of air that is circulated to the intake passage (20) between the air flow meter (21) and the supercharging device (41) through the bypass passage (51).

Abstract: An exhaust gas turbocharger for an internal combustion engine has a compressor arranged in an intake tract of an internal combustion engine for precompression of air passing through the intake tract to the compressor. A switchable air guiding device is arranged upstream of the compressor, wherein the switchable air guiding device supplies an air flow to the compressor in at least two different ways. The air guiding device has at least two components, wherein the at least two components are substantially made from plastic material.

Abstract: A control apparatus for an internal combustion engine according to the present invention includes: a turbocharger having a turbine disposed in an exhaust path and a compressor disposed in an intake path; a waist gate valve that opens and closes a bypass channel that connects a part of the exhaust path upstream of the turbine and a part of the exhaust path downstream of the turbine to each other; a drive mechanism that drives the waist gate valve; and waist gate valve opening controlling means that controls the drive mechanism so that the opening of the waist gate valve agrees with a saturation minimum opening when the drive mechanism opens the waist gate valve, the saturation minimum opening being the minimum opening at which the flow rate of an exhaust gas passing through the bypass channel is saturated.

Abstract: Four-stroke internal combustion engine comprising N groups of two or three cylinders the exhaust phases of which do not interfere with one another, the exhaust ports (6) of which are linked together by an individual exhaust manifold (3) which communicates with a common inlet manifold (2) and is linked to one of the N inlets (19) of a shutter (14) the single outlet of which is connected to the inlet of a turbine (5), common to the N groups and which is controlled in such a way as to open an exclusive communication between the turbine (5) and each exhaust manifold (3) at least for the duration of the puffs of exhaust gases emitted by one of the cylinders that it is emptying.

Abstract: An engine combustion air pre-cleaner includes a body shaped for effecting cyclonic air flow between an inlet and an outlet of the body. Located along a longitudinal axis of the body is a conical throttling member which is coupled to a control device which operates in response to increasing engine load, as represented by increasing boost pressure, torque and/or speed, to shift the throttling member so as to cause an increasing air flow with increasing engine load.

Abstract: An exhaust turbocharger is enhanced in durability and reliability by making the valve body of the waste gate valve contact the seat face of the turbine housing at the opening of two exhaust gas bypass passages uniformly without being affected by the end face of the partition wall partitioning the two bypass passages, thereby preventing generation of vibration and vibration sound(chattering) of the valve body and the occurrence of gas leakage due to defective seating of the valve body against the seat face of the turbine housing.

Abstract: A system for recovering engine exhaust energy is provided. The system includes an exhaust system including a first exhaust branch and a second exhaust branch. The system includes a first and a second group of exhaust valves associated with a plurality of engine cylinders. The system also includes an energy recovering assembly. The system further includes a control mechanism configured to control at least one of the first and second groups of exhaust valves according to a determined timing strategy based on at least one engine operating parameter.

Abstract: A two-stage turbo system using small-sized turbo-superchargers and simply configured. A two-stage turbo system provided with an internal combustion engine (1), two turbo-superchargers (2A, 2B) driven by exhaust gas from the internal combustion engine (1), control valves (V1-V5) for switching between the flow path of intake gas sucked into the internal combustion engine (1) and the flow path of exhaust gas from the internal combustion engine (1), and a control device for controlling the control valves (V1-V5) and the turbo-superchargers (2A, 2B).

Abstract: A fresh gas supply device is provided for an internal combustion engine having a turbocharger. The device includes a charge-air inlet for taking in charge-air from the exhaust gas turbocharger, a compressed air inlet for taking in compressed air, an outlet connectable to the charge-air inlet via a flap element and to the compressed air inlet via a flow regulating device, and a control unit for controlling the flap element and the flow regulating device. The flow regulating device has at least one valve for opening and closing the compressed air inlet and a proportional valve connected downstream in the direction of flow for setting a pressure in the outlet.

Abstract: A method for providing air to a combustion chamber of an engine, the engine including a compressor and a boost tank selectably coupled to an intake manifold. The method includes varying a relative amount of engine exhaust in air pressurized in the boost tank based on engine operating conditions, and discharging the air pressurized in the boost tank to the intake manifold.

Abstract: An internal combustion engine (100) includes an intake manifold (106) and at least one exhaust manifold (108). A first compressor (120) that is operably associated with a first turbine (128) has a first air inlet (126) and a first air outlet (118). The first air inlet (126) is adapted to admit air into the first compressor (120), and the first air outlet (118) is fluidly connected to the intake manifold (106). The first turbine (128) fluidly communicates with a tailpipe (138). A second compressor (124) is operably associated with a second turbine (160) and has a first tributary fluid inlet (152), a second tributary fluid inlet (154), and a second fluid outlet (122). The first tributary fluid inlet (152) is fluidly connected to the tailpipe (138) at a junction (147), the second tributary fluid inlet (154) is adapted to admit air into the second compressor (124), and the second fluid outlet (122) is fluidly connected to the intake manifold (106).

Abstract: A control device for an internal combustion engine including a turbocharger including a first exhaust channel leading to a turbine of the turbocharger, a second exhaust channel that does not lead to the turbine, a first exhaust valve that opens and closes the first exhaust channel, a second exhaust valve that opens and closes the second exhaust channel, and an exhaust variable valve mechanism that has a medium cam and a small cam as cams that drive the second exhaust valve and can change a lift amount and a working angle of the second exhaust valve by switching the cam profiles. The adjustment of the amount of exhaust energy supplied to the turbine and the adjustment of the turbine revolution speed and supercharge pressure are performed by switching the cam profiles of the second exhaust valve.

Abstract: Propellant management systems and methods are provided for controlling the delivery of liquid propellants in a space launch vehicle utilizing multiple rockets. The propellant management systems and methods may be configured to enable substantial simultaneous depletion of liquid propellants in each of a plurality of active rockets during operation of various booster stages of the launch vehicle.

Abstract: An engine provided with a variable parallel supercharging system (9) comprising a first supercharger (10) which is driven by exhaust gas which flows in a first exhaust gas route (41) and which pressurizes intake air which flows in a first intake air route (3) and also comprising a second supercharger (20) which is driven by exhaust gas which flows in a second exhaust gas route (42) and which pressurizes intake air which flows in a second intake air route (4), a supercharging pressure sensor (63) for detecting the pressure of the pressurized intake air, a first supercharger rotation sensor (61) for detecting the rotational speed of the first supercharger (10), a second supercharger rotation sensor (62) for detecting the rotational speed of the second supercharger (20), a first variable actuator (14) for adjusting the capacity of the first supercharger (10), a second variable actuator (24) for adjusting the capacity of the second supercharger (20), and a control device for controlling each of the variable actua

Abstract: A turbine flow cross-section of a turbocharger of an internal combustion engine, is set such that a lower limit (TSQ_dyn_min) of a range of settable values of the turbine flow cross-section is determined as a function of an operating parameter of the internal combustion engine in non-stationary operating states. A speed of the internal combustion engine can be used as the operating parameter.

Abstract: An exhaust brake control system includes a braking torque estimation module that estimates a desired braking torque based on engine speed. A volume flow rate determination module determines a desired volume flow rate of an exhaust gas based on the desired braking torque. An adjustment module adjusts an actual volume flow rate to control actual braking torque based on the desired braking torque and a change in exhaust temperature.

Abstract: An apparatus for controlling a throttle opening degree of a diesel engine with a supercharger is disclosed. The apparatus includes an electronic control unit having functions of detecting section, a computing section, a correcting section, and a correction limiting/inhibiting section. The detecting section detects the atmospheric pressure, and the computing section computes an atmospheric pressure correction value with respect to the throttle opening degree based on the detected atmospheric pressure. The correcting section corrects the throttle opening degree in accordance with the atmospheric pressure correction value. When the degree of separation of an actual charging pressure from a target charging pressure in the supercharger is les than a predetermined value, the correction limiting/inhibiting section limits or inhibits correction of the throttle opening degree in accordance with the atmospheric pressure correction value.

Abstract: A combustor having liners with a plurality of angled effusion holes defined therethrough at a first angle with respect to a surface of the liners and at a second angle with respect to a corresponding radial plane. A density of the effusion holes defined in a primary section receiving the fuel nozzles is at least equal to a density of the effusion holes defined in a secondary downstream section.

Abstract: An engine for a personal watercraft that is equipped with a supercharging machine, including a pressure release device that is configured to, when a pressure in a region of an air-intake passage of the engine that is located upstream of a throttle valve in an intake-air flow direction exceeds a predetermined value, release the pressure outside the air-intake passage.

Abstract: In a marine diesel engine equipped with a plurality of turbochargers, when the turbochargers are switched from single operation to parallel operation or from parallel operation to single operation, surging in the turbocharger to be started or stopped is prevented.

Abstract: A system and method for controlling boost pressure in various turbo-charged engine configurations as well as variable geometry turbine (VGT) arrangements includes an electronic controller programmed to receive a predetermined desired boost pressure PBoostdes. A desired pressure delta ?PWGdes across a waste-gate valve is determined using the desired boost pressure PBoostdes. A control signal is generated for controlling the waste-gate valve so as to achieve the desired pressure delta ?PWGdes. In boost pressure and vacuum pneumatically-actuated waste-gate valve arrangements, the respective solenoid duty cycles are obtained through use of various data structures. Where a waste-gate valve position is controlled by an electrical motor, the valve position is determined using a data structure as a function of desired waste-gate valve flow at sonic standard conditions.

Abstract: An exemplary flow path for an electrically assisted turbocharger (220) includes a first opening to an air intake path (114) of an engine (110), the first opening positioned downstream from a compressor (224) of the turbocharger (220); a second opening to an exhaust path (116) of an engine (110), the second opening positioned upstream from the turbine (226) of the turbocharger (220); and a valve (229) controllable by a controller (240, 150, 160) wherein the controller (240, 150, 160) includes control logic for controlling the valve (229) and for controlling an electric motor (228) of the electrically assisted turbocharger (220). Various other exemplary devices, methods, systems, etc., are also disclosed.

Abstract: A method is disclosed for preventing an underspeed event of a turbocharger. The method includes interpreting a turbocharger speed, a compressor differential pressure (CDP) and a turbocharger differential pressure (TDP). The method further includes calculating a thrust load capacity (TLC) based on the turbocharger speed, and calculating a current thrust load (CTL) based on the CDP and the TDP. The method further includes calculating a thrust margin based on the TLC and the CTL, and controlling an actuator in response to the thrust margin. Controlling the actuator includes maintaining the thrust margin to a thrust margin target, which may be a function of the turbocharger speed. The actuator is a turbine bypass valve, a compressor bypass valve, a variable geometry turbocharger position, an exhaust throttle and/or an exhaust gas recirculation valve that controls the turbocharger speed.

Abstract: A system and method for controlling air flow in an engine system. In one embodiment, the system includes an engine, a turbocharger coupled to the engine, and a compressor bypass valve coupled to the turbocharger and to the engine. The compressor bypass valve includes a mechanism that allows the compressor bypass valve to be closed by default and allows the compressor bypass valve to be actuated passively when acted upon by a boost pressure when the boost pressure increases above a predefined pressure threshold. According to the system and method disclosed herein, the compressor bypass valve is passive, and thus controls air flow to the engine without requiring active control circuitry or logic.