Abstract: A coolant recycling system is disclosed, including a chiller and a coolant filtering unit. The chiller includes a coolant tank, a compressor, a condenser and an expansion valve. The coolant tank includes an evaporator, a coolant outlet and an coolant inlet. The evaporator, the compressor, the condenser and the expansion valve are connected in sequence to form a refrigerant loop. The coolant filtering unit includes an unfiltered storage container, a dehydration filter and a filtered storage container. The unfiltered storage container is connected to the coolant outlet and the filtered storage container is connected to the coolant inlet.

Abstract: The present invention is related to a method and apparatus for locationing a instrument of tablet, wherein a very simple equation is used to locate a instrument, for example, a stylus pen. The stylus pen location on the a sense line grid which formed by a set of spaced conductors is converted to a digitized number and can be reported to the host computer for controlling the screen cursor or making a sketch drawing.

Abstract: The present invention is related to a tablet using a cordless pointing instrument, wherein the position of a pointing instrument, in general a pointing pen, in a predetermined line grid is converted into a digital number, meanwhile, the operation of the pointing pen is transferred to the inducing tablet.

Abstract: A system for determining a position of a wireless pointing device relative to the plane of a conductor grid, by inducing currents in the conductor grid, includes a pointing device and a digitizer tablet on which is situated the conductor grid. The pointing device includes an oscillator, a resonator circuit, and a coil to which a tuned alternating current is supplied, and which emits an alternating signal that induces currents in the conductor grid. The power supply of the pointing device includes a DC-DC converter circuit for enabling the power supply to operate with only one low voltage battery, and a voltage stabilizer for preventing drift in the frequency and phase of the signal emitted by the pointing device.

Abstract: A method and apparatus for producing a digital number representing the location of a pointing instrument with respect to a plurality of spaced conductors is disclosed. The instrument has a coil unit which produces an alternating magnetic field for inducing a plurality of alternating current signals in the plurality of spaced conductors, respectively, when an alternating current electrical signal is applied thereto. The conductors are sampled in a predetermined order so as to sense the induced alternating current signals. A phase sensitive detector is employed to detect a phase reversal between the induced alternating current signals induced in ones of the conductors located on opposite sides of the coil to produce a signal waveform which changes polarity in response to the phase reversal.