摘要:
A device for controlling an electrically actuable valve having a valve coil, including a main switch, situated in the current circuit of the valve coil, for adjusting the current flowing through the valve coil, and a freewheeling path, which has a freewheeling diode and is switched in parallel with the valve coil. A freewheeling switch is provided, by which the freewheeling path is able to be interrupted or closed. This allows for optionally operating the valve in a PMW or in a switching operation.
摘要:
The invention relates to an electric circuit configuration for switching an electrical load (3), particularly a solenoid valve, by means of at least one switching means (5) associated with the consumer (3), particularly a transistor. The circuit configuration comprises at least one analysis circuit comprising at least one measuring resistor (17) connected in series with the switching means (5), at least one first analysis means (23) for determining a parameter corresponding to the short-circuit current, and at least one second analysis means (25) for determining a parameter corresponding to the consumer current. The circuit configuration is characterized in that the first analysis means (23) is connected in parallel with the measurement resistor (17).
摘要:
A magnet controller supplied by an AC source controls a lifting magnet. Two bridges allow DC current to flow in both directions in the lifting magnet. During “Lift”, relatively high voltage is applied to the lifting magnet until it reaches its cold current. Then voltage is lowered. After a desired interval, once the magnet has had time to build its electromagnetic field, voltage is further reduced to prevent the magnet from overheating. The magnet lifting forced is maintained due to the magnetic circuit hysteresis. During “Drop”, reverse voltage is applied briefly to demagnetize the lifting magnet. At the end of the “Lift” and the “Drop”, most of the lifting magnet energy is returned to the line source. A logic controller controls current and voltage of the magnet and calculates the magnet's temperature. In one embodiment, a “Sweep” switch is provided to allow reduction of the magnet power to prevent attraction to the bottom or walls of magnetic rail cars or containers.
摘要:
A method for initializing valves of an engine having a starting apparatus is disclosed. The engine may have electromechanically actuated cylinder valves. The method comprises moving at least a first valve away from a neutral position of the first valve before the engine is rotated by said starting apparatus; and moving at least a second valve away from a neutral position of the second valve after the engine is rotated by said starting apparatus.
摘要:
Prior to the operation of a solenoid type of fuel injector, a DC voltage is applied across the injector to create a current through the injector that is below the activation current of the injector. A capacitor is then placed in series with the injector and the flyback energy from the injector transfers a charge onto the capacitor. When the injector current drops to a predetermined level, the capacitor is removed from the circuit and isolated. This process is repeated until a minimum charge is on the capacitor. By placing the capacitor charge onto the injector at the time that the injector is to be activated, the opening response of the injector is improved. By applying the charge on the capacitor to the injector in a manner to neutralize the eddy currents when the voltage across the injector is removed, the closing response is improved.
摘要:
A solenoid-operated valve actuating controller actuates a solenoid-operated valve by energizing an actuating coil of the solenoid-operated valve in a rated mode, enough to move a movable member in the actuating coil, during a first period. Further, the actuating coil is energized in a power saving mode, during a second period after the first period. The solenoid-operated valve actuating controller has a timer circuit for setting the first period, an oscillating circuit for energizing the actuating coil in the power saving mode during the second period, and a control circuit for stopping an oscillating operation of the oscillating circuit during the first period based on an output signal from the timer circuit, and for energizing the actuating coil in the rated mode.
摘要:
Prior to the operation of a solenoid type of fuel injector, a DC voltage is applied across the injector to create a current through the injector that is below the activation current of the injector. A capacitor is then placed in series with the injector and the flyback energy from the injector transfers a charge onto the capacitor. When the injector current drops to a predetermined level, the capacitor is removed from the circuit and isolated. This process is repeated until a minimum charge is on the capacitor. By placing the capacitor charge onto the injector at the time that the injector is to be activated, the opening response of the injector is improved. By applying the charge on the capacitor to the injector in a manner to neutralize the eddy currents when the voltage across the injector is removed, the closing response is improved.
摘要:
A bi-directional dual coil half bridge converter adapted to be coupled to a dual coil actuator of a cylinder valve in an internal combustion engine is described. In one example, the converter has a first and second capacitor and a voltage source, where the converter is actuated via switches to individually energizing coils in said dual coil actuator. A voltage regulator is also shown for maintaining midpoint voltage during unequal loading of different actuator coils in the converter.
摘要:
A very small fixed current is passed through the coil of a solenoid during use thereof when the solenoid is in its “off” state of cyclic PWM command, the fixed current being less than the current required to actuate the solenoid to the “on” position. While the current is flowing through the coil, the voltage across the coil is measured. The resistance of the coil is calculated according to Ohm's Law. When the actual resistance is known, the duty cycle imposed on the solenoid may be altered to compensate for the resistance deviation from nominal. This allows, for example, fuel injectors for internal combustion engines to deliver the correct amount of fuel under all operating conditions.
摘要:
In a single device for controlling electro-injectors and electrovalves in an internal-combustion engine, a first control circuit for each electro-injector, a second control circuit for each electrovalve, and a timing circuit, supplying timing signals to the first and second control circuits. In the second control circuit, switches selectively connect the respective electrovalve to a first voltage source in certain given operating conditions, and to a boosted voltage source, constituted by a capacitor for accumulation of energy, in certain other given operating conditions. In this way, part of the electrical energy accumulated in the electrovalve during its normal actuation is transferred to the capacitor, thus causing the latter to be recharged.