Abstract: A replaceable heat transfer module. The replaceable heat transfer module has an inlet floodbox with fluid distribution passageways, an outlet manifold with fluid collection passageways, and extending in a fluid tight relationship between the fluid distribution passageways and the fluid collection passageways, a thin, elongate evaporator envelope. The evaporator envelope has a lower flexible planar sheet and an upper flexible planar sheet, each having inner surfaces located in a back-to-back spaced apart relationship. The evaporator envelope has an upper end wherein the lower and upper flexible planar sheets are fluidly sealed to the inlet floodbox, and a lower end wherein the lower and upper planar sheets are fluidly sealed to said outlet manifold. Mylar brand polyester is used for construction of the evaporator envelope. A marginal area on each side extends lengthwise transversely beyond the inlet floodbox and the outlet manifold to provide sloping sidewalls for containment of a working product.

Abstract: Frequency translation circuitry consisting of a delay circuit, a digital register, an XOR gate and digital frequency dividers which provides output signals differing in frequency by a specific amount determined by the frequency of only one input signal.

Abstract: The output signal frequencies of two current controlled oscillators are made to track closely by matching timing currents with a current mirror. A frequency difference between the output signals is obtained by establishing an additional timing current for only one of said oscillators.