Abstract: A fuse or ignition conductor for conducting ignition from an igniter to a remotely located primer, as used in the detonation of explosives. The ignition conductor contains a light transmitting fiber optic cord bound to the ignition conducting material of the fuse in such manner that if the ignition conducting material is broken, the fiber optic cord is also broken. The claimed subject matter further includes assemblies containing means at the primer end for transmitting light back to the igniter end.

Abstract: A continuity checking system for detonating cord having four principle parts. The detonating cord has a fiber optic cord associated therewith to run from the blasting cap to a remote primer; a light return device is installed at the primer; a disposable testing head is installed at the end of the detonating cord adjacent the blasting cap; and a testing device is positioned a safe distance away from the disposable testing head. The testing head utilizes an LED with means for illuminating the end of the fiber optic cord, and a light sensitive device with means for sensing return light from the fiber optic cord. An electrical input signal, and an electrical output signal from the disposable testing head is communicated by electrical wires to the remote testing device.

Abstract: An object of the present invention is the provision of a new and improved vehicle anti-theft device wherein electrical switches are located in the operator compartment of the vehicle and must be actuated in proper sequence to transmit simple make or break functions through wires leading to electronic circuitry that is located in a locked area, and which controls the ignition circuit. Additional code actuated circuitry is provided to permit authorized personnel, e.g. parking attendants, to operate the vehicle.

Abstract: A control circuit utilizing: a counter which provides first and second output signals at spaced apart time intervals and delay means for stopping and starting the counter; and switch means having start and stop inputs and an output connected to the delay means of the counter. The switch means, being arranged to start the counter when the start input is energized, and being arranged to stop the counter when the stop input is energized. The stop input of the switch means being actuated by the first counter output signal.

Abstract: A homing system utilizing a loop antenna positioned at approximately 45.degree. to the vertical to provide an electromagnetic field having both horizontal and vertical components. These signal components are picked up by a vertical loop stick antenna alternately connected to one of two bifilar wound coils of a horizontal loop stick antenna to provide alternating signals. The strength diagrams for the alternating signals are cardioid shaped and are arranged back to back with their null point passing through the intersections of the back to back signals. The null point of both antenna systems occurs when the horizontal loopstick antennas are at right angles to the electromagnetic lines of force; and any time that the horizontal loop sticks are turned at an angle relative to their null point, a difference in signal strength exists between the two antenna systems. This is picked up, and is amplified at separate time intervals by a common amplifier.