Abstract: A heat exchanger for use where any of a number of possible configurations of ductwork are possible, includes an approximately rectangular housing having a first panel with a surface area and with four corners including a first and a second corner situated diagonally opposite one another, and a third and fourth corner situated diagonally opposite one another. A heat exchanger is coupled to the panel situated approximately diagonally within the housing spanning from approximately the third corner to the fourth corner such that the housing is partitioned into a first chamber adjacent the first corner and a second chamber adjacent the second corner. A first duct is situated near the first corner on the first panel and occupying less than approximately 1/4 of the surface area, for coupling air to the first chamber. A second duct is situated near the second corner on the first panel and occupying less than approximately 1/4 of the surface area, for coupling air from the second chamber.

Abstract: A remotely controlled chroma key soft edger is described for use with an analog switcher. The keying signal is a low passed filtered and differentially summed with substantially an unfiltered keying signal and the resultant high frequency components are summed with the low pass filtered signal. The gain of the peaking signal is remotely controlled to adjust the summed rise time of the keying signal.

Abstract: A remotely controlled chroma keyer is provided which is responsive to the red, green and blue signals from a video source such as a color camera for providing color difference signals. A signal processing system using quadrant multipliers is used for summing and differencing these color difference signals which when applied to a non-additive mixer select a particular color. The color selection is determined by control voltages applied to the multipliers.