Abstract: Three different embodiments of the ultrasensitive differential point contact relay configuration of this invention are disclosed. The first or basic embodiment is particularly suited for use in intrusion detection systems or as a strain gauge/accelerometer and the like. The second embodiment is particularly suited for use as an ultrasensitive electrically actuated relay and the like. The third embodiment performs the function of an ultrasensitive strain gauge/accelerometer whose output is the mix of the mechanical and electrical stimulus. The basic embodiment comprises a point contact relay housed in a two section case or container. The two sections of the container are joined by a lower modulus section. A movable contact arm is spring biased against a second movable contact and the base of the contact arm floats in a viscous fluid. In the second embodiment the case or container is formed as one section and a piezoelectric crystal is mechanically coupled to the second contact.

Abstract: A fuel cell utilizing direct hydrocarbon oxidation is disclosed. The fuel ll comprises an anode, a cathode, a fuel compartment, an oxidant compartment, a compartmented electrolyte chamber and an electrolyte disposed in the compartmented electrolyte chamber. The basic electrolyte utilized is the monohydrate of trifluoromethyl sulfonic acid CF.sub.3 SO.sub.3 H.H.sub.2 O.

Abstract: Circuitry for providing the opening of circuit breaker contacts at a zero load current crossing is disclosed. A sensing circuit senses the phase relationship of the load current with respect to time and provides a square wave voltage in phase with the load current. This square wave voltage is phase shifted and this phase shifted signal is used to control the opening of the circuit breaker contacts at a zero load current crossing point.

Abstract: Apparatus for indicating the frost line depth of the ground for example is isclosed. The apparatus includes an outer hollow tube that is buried in the ground; an inner sleeve or tube filled with a mixture of sand and a temperature sensitive dye fits inside the outer tube. The inner tube is attached to an end cap by rope or like and the end cap is threaded to mate with threads provided at the end of the outer tube that protrudes above the ground. After the apparatus has been in place for a length of time sufficiently long to permit the apparatus to attain the same temperature as the surrounding ground, the inner tube is removed to read the depth to which the ground is frozen. The dye in the inner tube changes color to the depth at which the ground is frozen and remains the same color below this depth. The inner tube is provided with gradations so that depth can be read directly from the tube.