An air core gauge is provided with a plurality of angularly oriented coils. Switching means are connected to the coils in order to control the flow of current therethrough. Pulse generators responsive to variations in frequency of electrical signals representative of a condition, such as vehicle speed or engine RPM, control the switching means so as to cause excitation of the coils to produce a resultant mmf vector, the angular position of which is related to the frequency of the signals. The resultant mmf vector causes a magnet and associated pointer to rotate to thereby provide an indication of the value of the condition.

A moving magnet type indicating instrument comprising a moving magnet type instrument, a counter mechanism, a drive unit, and a frame body produced of a synthetic resin. The magnet type indicating instrument includes a magnet mounted in bobbins produced of the synthetic resin, a needle shaft fixed to the magnet, and a coil wound at an angle on the bobbins. The bobbins are housed in a magnetic shield case and the coil is electrically connected to terminals provided on the bobbins. The counter mechanism, including a total counter and reset counter having a zero-resetting device, is mounted on the frame body. The drive unit comprises a case including a step motor for driving the counter mechanism and a groove of gears, and is fixed to the frame body. Terminals for the moving magnet type indicating instrument and the drive unit are inserted and connected to the connectors provided on a printed-circuit board. Therefore, it is possible to easily electrically connect and fix the moving magnet type indicating instrument and the drive unit to the connectors on the printed-circuit board through these terminals.

A method of operating a hybrid temperature control system. The method provides an evaporator, which has a discharge line, a supply line, and a evaporator coil. The evaporator coil is in fluid communication with the discharge line and the supply line. The method also provides a microprocessor, which regulates a supply of a heat absorbing fluid to the evaporator. The method further couples a sensor module to the microprocessor. The sensor module is near the evaporator, senses a temperature of a gas exiting the evaporator, and sends a temperature to the microprocessor. The method also turns off the supply of the heat absorbing fluid to the evaporator when the microprocessor determines that the temperature of the gas exiting the evaporator reaches a predetermined temperature.

A method of temperature control in a cryogenic system, wherein the system includes a cryogenic tank. The method comprises providing a motor speed sensor which determines a motor speed, providing a pressure sensor which determines a cryogenic pressure, providing a temperature sensor in the conditioned space which measures a temperature within the conditioned space, providing a deprived integral region, and generating an overriding control signal at the proportional-integral-derivative controller when the temperature and the pressure are beyond a temperature set point and a pressure set point.

An apparatus and a method for conditioning air in a plurality of spaced apart and thermally separated conditioned spaces with a cryogenic temperature control apparatus. The apparatus includes a storage tank housing a cryogen, an evaporator coil being selectively moveable into and out of thermal communication with the plurality of conditioned spaces for alternately conditioning air in the plurality of conditioned spaces, and a flow path fluidly connecting the storage tank and the evaporator coil.