Abstract: A vacuum control device is configured as an integrated assembly having a fluid inlet port, a fluid outlet port and a controlled vacuum output port, and houses both a venturi and solenoid-operated fluid-flow control valve unit. The valve unit has a fluid-flow chamber, in which a translatable spool valve element serves to control fluid communication between the fluid inlet port and the fluid inlet of the venturi. The output of the venturi is coupled by way of a fluid passageway to the outlet port, while a vacuum port of the venturi is coupled to a controlled vacuum output port. The valve unit contains a solenoid device, which is coupled with the translatable spool valve element, for controlling the displacement of the valve element and thereby fluid communication between the fluid inlet and the fluid outlet ports through the venturi. The solenoid-operated fluid-flow control valve unit preferably employs, as its movable armature, a steel bearing ball.

Abstract: An excessive duty cycle and pulse width limiter comprises two constant cunt sources responsive to changes in a control input signal to provide a constant voltage charge and discharge current to a capacitor whose voltage level is sensed by a tripping circuit. The circuit effectively measures duty cycle and is used as a protective limiter, providing output pulse blanking signals to load circuitry.