Abstract: The invention relates to a valve comprising a valve housing (1) and a manually actuatable valve part (5) which is arranged therein in a longitudinally displaceable manner, said valve part controlling the free passage cross-section for fluid between the two connection points (10, 17) in the valve housing at given adjustment positions. The valve is characterized in that a latching device (55, 57) is provided between the valve housing and the valve part, which lets the valve part assume its re¬spective adjustment position only in stages and in a releasable manner.

Abstract: A protective arrangement for an electromagnetic load is disclosed. In this protective arrangement, the load and a control transistor form a series circuit from the battery voltage to ground and a series circuit of a free-wheeling transistor and a free-wheeling diode is connected in parallel with the load. By coupling the base of the free-wheeling transistor to ground, this transistor is made continuously conductive provided that the polarity of the supply voltage is correct, whereas, this free-wheeling transistor blocks if the supply voltage polarity is incorrect. This assures that none of the components is in danger of being destroyed in the event that the polarity of the supply voltage is incorrect.

Abstract: An apparatus is proposed for driving electromagnetic devices, in particular electromagnetic injection valves in internal combustion engines. The apparatus includes a signal source for actuating pulses and is characterized in that at least one timing circuit is provided for advanced magnetization, preferably dependent on operating characteristics, of the electromagnetic device. The apparatus achieves the most linear possible relationship between the duration of the actuating pulse and, for example, the opening time of the injection valve. In this manner, the fuel quantity to be supplied to the internal combustion engine can be more precisely dosed and the operational behavior of the engine can be made optimal.

Abstract: An apparatus is proposed for controlling the electric current through inductive consumers, in particular through a fuel metering valve in internal combustion engines, this apparatus representing a two-point closed-loop controller and functioning with a single threshold switch for an upper and a lower threshold. The apparatus includes one current-measuring resistor each in the freerunning circuit and in the main current circuit, both measuring resistors being members of a voltage divider between the two supply voltage lines and whose middle junction is carried to the threshold switch. By means of a resistor-diode network in combination with the threshold switch, a correction can be made in the individual switching thresholds in accordance with supply voltage.

Abstract: An apparatus is proposed for controlling the de-excitation time of electromagnetic devices, in particular electromagnetic injection valves in internal combustion engines, wherein a switch (or an actuation circuit in general) is disposed in series with the device, characterized in that a circuit arrangement with a controllable output potential is disposed in series or in parallel with the electromagnetic device. It is the purpose of the apparatus to linearize the current decrease through the electromagnetic device after the end of the actuation pulse and preferably to simultaneously control its rate of decrease. As a result, control of the de-excitation time of the particular electromagnetic device is attained. In terms of function, the circuit arrangement represents a controllable Zener diode.

Abstract: An installation for the operation of electromagnetic loads, especially solenoid valves, in fuel supply systems in internal combustion engines, wherein a measuring resistor as well as a switch are connected in series with the load and the entire arrangement is connected to the two supply voltage terminals. The installation comprises two comparators connected in parallel with the measuring resistor, at least one resistor being connected in front of these comparators, and controllable current source arranged between the junction of the threshold switch and the resistor in the proximity of the load, as well as a supply voltage terminal. The supply voltage of one of the comparators is made dependent on the voltage in the freewheel circuit, to maintain at least one of the comparators in the operating position even during freewheeling operation.

Abstract: A method is proposed for operating an electromagnetic load device with a movable armature, especially an injection valve of an internal combustion engine. The load device is supplied, at the beginning of trigger pulse, with a high amperage current and, at least toward the end of the pulse, with a reduced current. This method is characterized in that, starting with a certain amperage, at which preferably the armature is set into motion but has not as yet reached its final position, the current rise is at least reduced. The apparatus aspect comprises a measuring element and switching element connected in series with the load device. A threshold switch is associated with the measuring element to control the switching element. The switching thresholds of the threshold switch can be controlled in dependence on current and/or on time. The first current threshold is at a value at which the armature of the load is preferably being moved, but has not yet reached its final position.

Abstract: Electronic control circuitry is provided for controlling the actuating current of electromagnetic devices and in particular of the electromagnetic fuel injection valves of an internal combustion engine. In order to program the magnitude of the actuating current from an initial high level to a lower maintenance level, there is provided a driver circuit which receives fuel injection control pulses from a fuel injection system, not itself part of the invention, and processes these control pulses into valve-actuating current pulses. The valve current is sensed by suitable transducer, for example a resistor, and the resulting signal is fed to a two-point controller which suitably alters the input to the driver circuit to thereby change the valve actuating current. The set-point value on which the two-point controller operates is itself subject to change by means of a suitable circuit.

Abstract: The motor is serially connected with a diode and a sensing resistor so that half waves of one polarity, for example negative, can flow through the motor and provide, across the resistor, a voltage drop corresponding to loading placed on the motor. A thyristor is connected in parallel to the diode and reversely poled to conduct the other half wave, then the positive, if triggered. Triggering of the thyristor is controlled by the voltage drop across the sensing resistor so that, under no-load conditions, only the negative half waves will be applied to the motor, thus limiting its no-load speed but, as loading is placed thereon, increasing portions of the positive half waves are likewise passed through the motor.