Energy transfer circuits

摘要

905,953. Electric digital to analogue converters. THOMPSON RAMO WOOLDRIDGE Inc. April 16, 1959 [Aug. 14, 1958], No. 13016/59. Class 40 (1). [Also in Groups XIX and XL (c)] In a circuit for converting digital signals to analogue signals, negative-going digit pulses applied to transistor Tb cause capacitor 21b to discharge into a storage capacitor 31 and so incremently increase the voltage across the latter capacitor. This voltage is applied through emitter followers 51, 52 to an output terminal and is also fed back through a rectifier 41b to bring the potential at the right-hand terminal of capacitor 21b up to the potential across the capacitor 31 so that each successive input pulse causes equal increments of voltage across capacitor 31. Positive-going digit pulses applied to transistor Ta effect equal decrements of voltage across capacitor 31 in a similar manner. In an alternative arrangement (Fig. 4, not shown), the transistors and semi-conductor rectifiers are replaced by thermionic valves.