A piezoelectric touch screen assembly can be attached to mounting ears on an ordinary CRT assembly. The touch screen assembly includes a frame, a glass plate which is seated on a gasket at one surface of the frame and a plurality of piezoelectric elements which are bonded to the glass plate and are "trapped" between the CRT face and the glass plate. Studs extend outwardly from the CRT ears through openings in the frame. Coil springs are placed on the studs and are trapped by washer nuts to load the touch screen assembly toward the CRT by a predetermined amount. Grommets with a unique cross sectional configuration are mounted at the openings through the frame. The grommet is designed to provide minimal resistance to movement of the touch screen assembly toward or away from the CRT face but greater resistance to movement of the assembly in other directions.

A device-implemented method for driving a ferrimagnetic load (10), such as a phase shifter in an antenna array, which precisely meters the amount of magnetic flux imparted to the load (10) by sensing the voltage applied to a winding and integrating the sensed voltage over time. The time intergrated voltage is proportional to the magnetic flux imparted to the load (10) and is constantly compared to a preprogrammed value stored in a memory (18). When the sensed voltage reaches the preprogrammed value, the voltage is removed from the load (10) so that a metered amount of magnetic flux, proportional to the preprogrammed value, remains in the load (10). The load (10) is initially reset by delivering current in one direction through its winding until saturation is reached. The load (10) is set with a metered amount of magnetic flux by delivering current in the opposite direction through the winding. A current sensing circuit (68) senses the point at which the load (10) becomes saturated during the reset cycle and also senses current flow through the winding during the set cycle in order to prevent a current overload.

A method of ordering and an order entry system which includes a display showing, pictorially, the elements or items to be selected from a menu. An aiming selector is used to make the selections desired. Each item on the menu contains a light-responsive detector which is selected by aiming the aiming selector at the desired item. A first light signal from the selector falling on the detector of the desired item causes the item about to be selected to "flash" on the display, and a switch on the selector, when actuated, causes a second light signal to fall on the associated detector for the item to make the selection. A control element having a similar detector is similarly used to enter a command like "Total Up Order" which is used by the system to calculate the monetary value of the order.

A moveable traffic signaling which includes a trailer having wheels and a supporting structure; a general purpose message board supported by the supporting structure of the trailer, for communicating to drivers of passing vehicles a user-selected alpha-numeric message; an operator interface mounted on the supporting structure, for programming the message to be displayed at the site at which it is to be displayed; and a controller supported by the supporting structure, connected to interact with the operator interface and connected to provide the programmed message to the message board.

An audio system is disclosed wherein music cartridges are utilized in a series of cartridge racks for non-mechanical playback and recordation of an entire music collection. The audio signals are stored on music cartridges which are insertable into one of a plurality of cartridge racks. The cartridge racks are operatively connected with the music player of the audio system. The audio system is completely solid state, i.e. it has no moving parts and has the advantages of allowing quick and reliable playback and storage of any music cartridge of the user's entire selection, as desired by the user. The system is self-programmable and expandable, whereby additional cartridge racks can be connected for additional storage of music cartridges allowing any music cartridge from the entire collection to be accessed at anytime.