Abstract: A heating and cooling apparatus having a first gas conduit, a second gas conduit and at least one thermoelectric module. In a first embodiment, structure is provided to introduce moisture into the second gas conduit, upstream of that conduit's association with the thermoelectric module. The introduction of the moisture into the gas within the second gas conduit functions to decrease the temperature between the temperature of the gas in the first conduit and the temperature of the gas in the second conduit, thereby optimizing the operation of the thermoelectric module. In a second embodiment a plurality of thermoelectric modules are arranged in an array and positioned between the gas conduits and associated therewith. The power supplied to each of the thermoelectric modules is adjusted to correspond to an optimum power input calculated for each thermoelectric module respectively.

Abstract: A heating and cooling apparatus having a first gas conduit, a second gas conduit and at least one thermoelectric module. In a first embodiment, structure is provided to introduce moisture into the second gas conduit, upstream of that conduit's association with the thermoelectric module. The introduction of the moisture into the gas within the second gas conduit functions to decrease the temperature between the temperature of the gas in the first conduit and the temperature of the gas in the second conduit, thereby optimizing the operation of the thermoelectric module. In a second embodiment a plurality of thermoelectric modules are arranged in an array and positioned between the gas conduits and associated therewith. The power supplied to each of the thermoelectric modules is adjusted to correspond to an optimum power input calculated for each thermoelectric module respectively.

Abstract: An electronic system connected to a power transmission line having a fluctuating load for automatically providing increments of voltage to the line to supplement voltage losses from the load by sequentially connecting tapes on the windings of a transformer in response to changes in line current.

Abstract: A unitary optical guidance system and apparatus directs operators of vehicles such as airplanes, watercraft, trucks, and automobiles along a path or to a predetermined location (e.g., parking an aircraft at a terminal gate or landing an aircraft on a runway) with a high degree of accuracy. The apparatus projects one or a plurality of different colored rays of light in separate and substantially parallel colored light lanes. Light from the apparatus generally is directed at an incident angle with respect to the operator of an approaching vehicle such that upon proximity of the vehicle to a predetermined location, one of the colored lanes of light will be seen by the operator. Where multiples lanes of light are projected, the initial lane color may be traversed until a final lane color is encountered indicating that a desired or predetermined location has been reached.

Abstract: A phase detector for monitoring the presence, sequence and polarity of each phase line for a three-phase power input and indicating when a phase is missing or out of sequence.

Abstract: A control for controlling the operation of a direct current motor by select application of a three phase alternating current line input of given frequency to the armature thereof through solid-state forward and reverse designated switches which are gated by select enable inputs.

Abstract: A vertical descent rate detector switch has a pair of contacts which are magnetically actuated when the rate of vertical descent of the switch exceeds a set amount.

Abstract: A control for the motor of a mechanism which adjusts the position of the distal end of a passenger loading bridge, which control, when actuated, causes the motor to operate and the adjustment mechanism to move the end of the bridge to a preset position.

Abstract: A brake system for an aircraft passenger loading bridge monitors the operation of a drive system which raises and lowers the bridge. In the event of a malfunction of the drive system, the brake system interrupts power to the drive system and actuates a brake to prevent further operation of the drive system.