Abstract: A two-speed resolver system wherein the rotor of a fine brushless resolver which is directly connected to the shaft to be instrumented is connected to the rotor of a coarse resolver so that the rotor ofthe coarse brushless resolver rotates at a proportional but different rate than the fine resolver and the electrical output of the fine resolver which represents the position of the input shaft is fed to the electrical input on the coarse resolver and combined with the mechanical input to the coarse resolver to provide a signal out of the coarse resolver which indicates a predetermined fraction of angular rotation for each revolution of the rotor of the fine resolver. The disclosed two-speed resolver system utilizes brushless resolvers wherein the electrical connections to the rotors are through brushless rotary transformers. Two gears having a different number of teeth can be used to couple the rotor of the fine resolver to the rotor of the coarse resolver.

Abstract: A tracking digital angle encoder utilizing a translator, for providing the difference between an analog angle input and a digital angle input, a counter, which feeds the digital angle input to the translator, a detector, which controls the counter and is connected to the output of the translator to be activated by the output of the translator exceeding a predetermined trigger value, all of which are connected to cause the counter to count to a position where the output of the translator is less than the predetermined trigger level. When the output of the translator is less than the predetermined trigger value, the output of the counter provides a digital signal which closely approximates the analog angle input to the translator.

Abstract: A transducer for combining an analog signal input and a digital signal input and providing an analog signal output, equal to the sum or difference, wherein the digital input signal is divided into a first component, for which a very accurate analog equivalent is provided and a second component for which a good approximate analog equivalent is provided. The translator is usually used in conjunction with a resolver which provides analog inputs in suppressed carrier trigonometric form. The translator performs certain trigonometric manipulations on the inputs from the resolver and the analog equivalents of the digital angle in order to obtain a signal proportional to the difference between the sensor resolver position and the digital angle command position. The first component of the digital angle, for which very precise analog equivalents are provided, uses a minimum number of high precision resistors.

Abstract: A four-quadrant full-wave static converter having improved time response without current cross-over deadband. An alternating current wave is imposed on the direct current input signal, which generates gate pulses for appropriate thyristors at the desired firing angle. The applied alternating current signal can be of approximately the same magnitude as the converter deadband, so as the direct current signal varies from zero a portion of the control signal moves out of the deadband area. For fast response the magnitude of the alternating current signal can be greater than the deadband signal. As the magnitude of the direct current signal increases the relative magnitude of the alternating current signal is decreased, preventing a large DC component from being imposed on the supply during high current operations. Cycling of the imposed alternating current waves is synchronized with the firing angle point O to maintain system protection.