Abstract: A remote control device for the joint or successive remote control of radio receivers, record players, tape recorders, television receivers and the like comprises a body having a plurality of control buttons for the items of equipment to be remotely controlled. The device further has a plurality of superimposed drop sheets each of which is associated with a specific item of equipment or function type. With the aid of a flap which is pivotally mounted on the body and a gripper provided on the flap, it is possible to raise the drop sheets, so that only that particular sheet required for the desired function type is present on the device. The drop sheets have openings through which the operating buttons can project. In the vicinity of these operating buttons a reference to a specific function is provided on each drop sheet.

Abstract: Variably delaying an audio signal by storing digital representions of the audio signal at sequential memory locations prescribed by an encoding pointer operating at one clock rate, and reading from the memory at sequential locations prescribed by a decoding pointer operating at the same or a different clock rate, with the difference in clock rates between the pointers prescribing the rate of change of delay. A memory addressing system in which a processor specifies the high-order portion of a memory address and a separate counter, clocked at a much higher rate than the processor, provides the low-order portion of the address.

Abstract: Generating clock signals of slightly different frequencies without the signals locking up in synchrony, by providing a voltage-to-frequency converter driven by the output of an integrator, which is supplied with a signal representative of the sum of a frequency-difference command and the difference in frequency between the two clocks.

Abstract: Delta encoding circuitry of the type in which a digitally-encoded signal is determined by the difference between a present value of an input signal and a reconstructed signal representative of a past value of said input signal. The occurrence of a high or a low state in the digitally-encoded signal corresponds to an incremental change in the input signal of an amount dependent upon a reference signal determined from said digitally-encoded signal. The reference signal is increased by a positive-feedback circuit upon detection of one or more consecutive repetitions of the same digital state in the digitally-encoded signal.

Abstract: Apparatus for extracting recorded natural ambience from two audio channels while eliminating the cave-like quality of the sound of a soloist or announcer. The two channels are combined such that signals common to the two channels in a midrange of audio frequencies are cancelled, and the combined signal is time delayed.

Abstract: In an electrical system of the type in which a digitally encoded signal is determined at least in part by the difference between a present value of an input signal and a reference signal representative of a past value of the input signal, improved circuitry for generating the reference signal. The improved circuitry comprises extraction means including a filter for extracting from the pattern of bits in the digitally encoded signal information relating to the time derivative of the present value of the input signal and an envelope detector for processing the output of the filter to provide a control signal, and integrating means responsive to the control signal to provide the reference signal.