摘要:
Normally, an air-fuel ratio is controlled in accordance with the engine speed and the intake air quantity of an internal combustion engine with a turbocharger. When the output pressure of the turbocharger increases excessively, an intake relief valve opens to decrease the intake air quantity. In this case, the fuel injection quantity is controlled solely in accordance with the engine speed.
摘要:
In a method of supplying fuel to an internal combustion engine during start-up, the occurence of combustion is detected to arrest the change of the fuel supply quantity until steady-state engine operation is achieved. Combustion is detected by comparing sensed engine speed to a minimum engine speed resulting from combustion in the cylinders. Additionally, control values used to derive the start-up fuel quantity are modified so that the fuel quantity increases monotonically from a relatively low initial value until fuel ignition is detected.
摘要:
A back-up system for an engine coolant temperature sensor detects deviation of the output of the temperature sensor from its designed output range to produce a fault signal. In response to the fault signal, an engine control system derives the engine coolant temperature indirectly from other engine conditions. This derivation is based on two facts: (1) the amount of fuel required to start the engine is related to engine temperature, and (2) since the calorific value of a given engine is essentially constant, the rate of increase of engine temperature is related to the integrated number of engine revolutions. Thus, when the engine is to be started, engine temperature can be derived by gradually increasing the fuel supply quantity from a minimal initial value until the engine is able to start to determine the required fuel supply quantity. Thereafter, the derived temperature value can be updated as a function of total engine revolutions.
摘要:
An air/fuel ratio control system is applicable to lean mixture combustion internal combustion engines. The control system determines the value of the mixture ratio at which engine stability can switch between stable and unstable conditions. As long as the engine continues to run in a stable condition in which the engine roughness is within an acceptable range, the mixture is intermittently leaned out by a given proportion. On the other hand, when engine roughness in an unacceptable range is detected, the mixture ratio is enriched by a given proportion to overcome the unacceptable engine roughness. Enrichment of the mixture is continued until engine roughness within the acceptable range is detected.
摘要:
A system for detecting and controlling an engine knocking the determination of occurrence of knocking is based on a present data on the detected pressure vibration energy in a combustion chamber of the engine and a value associated with a previous data on the detected pressure vibration energy in the combustion chamber so that an accurate detection of engine knocking can always be achieved. Furthermore, the knocking can be discriminated from the background noise even when the engine revolution speed is high.
摘要:
Fuel consumption of a declerating automotive vehicle internal combustion engine is reduced while preventing stalling. In response to a valve for selectively supplying air and fuel to the engine being in a fully closed condition, a first signal is derived. In response to the engine speed dropping below a first predetermined value a second signal is derived. In response to derivation of the first and second signals a controller for the valve is activated. The controller responds to engine and brake responsive parameters of the vehicle for opening the valve in respone to any of: (a) the engine being decelerated under no load, and (b) the brake being abruptly applied and (c) the engine speed dropping below a second value. The second value is less than the first value and is determined in response to the rate of change of engine speed.
摘要:
A power converter includes an input terminal configured to be connected to a power supply, an output terminal, and a first switching element coupled between the input terminal and the output terminal. The first switching element includes a semiconductor multilayer structure formed on a substrate and made of a nitride semiconductor, a gate electrode formed on the semiconductor multilayer structure, a first and a second ohmic electrode, and a back electrode formed on a back surface of the substrate. A potential is supplied from the power supply connected to the input terminal to the back electrode so that a potential difference between the back surface and the second ohmic electrode is reduced. When the first switching element is in the on-state, a positive voltage bias is applied to the back electrode.
摘要:
A field effect transistor includes a first nitride semiconductor layer 13 and a second nitride semiconductor layer 14 having a band gap larger than that of the first nitride semiconductor layer 13 which are formed in this order in an upward direction on a conductive substrate 11, a source electrode 15 and a drain electrode 16 which are electrically connected to a two-dimensional electron gas layer 21, and a gate electrode 18. A rise voltage of a drain-substrate current is lower than a rise voltage of a drain-gate current and a rise voltage of a drain-source current.
摘要:
In a nitride semiconductor based bipolar transistor, a contact layer formed so as to contact an emitter layer is composed of n-type InAlGaN quaternary mixed crystals, the emitter layer and the contact layer are selectively removed so that the barrier height with the emitter formed thereon is small, and the ohmic electrode contact resistance can be lowered on the InAlGaN quaternary mixed crystals, for example, so that a WSi emitter electrode becomes an eave. A base electrode is formed by a self-aligned process using the emitter electrode as a mask. By such a configuration, the distance between the emitter and the edge of the base electrode is sufficiently shortened, and the base resistance can be lowered. As a result, a bipolar transistor having favorable high-frequency characteristics can be realized.
摘要:
A semiconductor device includes: a first nitride semiconductor layer having at least one projection on an upper surface thereof; a second nitride semiconductor layer formed on a top surface of the projection of the first nitride semiconductor layer and having a higher carrier concentration than the first nitride semiconductor layer; a first electrode formed on the second nitride semiconductor layer so as to overhang like a canopy and functioning as one of a source and a drain; and a second electrode formed to the side of the projection on the first nitride semiconductor layer and functioning as a gate.