Browse Prior Art Database

Frequency Switching

IP.com Disclosure Number: IPCOM000098154D
Original Publication Date: 1960-Feb-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Landauer, R: AUTHOR

Abstract

Two inductively coupled resonant circuits may be made to oscillate in either of two frequency modes. The particular mode is selected by varying any of several circuit parameters.

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Frequency Switching

Two inductively coupled resonant circuits may be made to oscillate in either of two frequency modes. The particular mode is selected by varying any of several circuit parameters.

The oscillator contains a parallel resonant circuit made up of inductor L(2) and capacitor C(2). Coupled inductively to this is another parallel resonant circuit comprising inductor L(1) and ferroelectric capacitor C(1). The value of capacitor C(1) is electrically controllable by the bias supplied by E. With the bias held at point A, the frequency of the output is in Mode 1. As the bias is increased the frequency increases slightly, until, at point B, Mode 2 takes over. If the bias is further increased, point D is reached. If the bias is decreased, point C is reached. Therefore, if the bias is set to a value which holds the oscillations at point X in Mode 1, bistable operation is possible. A pulse in series with the bias, with a magnitude sufficient to drive the bias past point B, changes the output oscillations to point Y in Mode 2.

Computer logic may be performed by applying control pulses in series with the bias supply, to switch the mode of the output oscillations. If the bias is set at the value corresponding to X and Y, and the oscillator brought into oscillation gradually by increasing its B+ voltage, for example, then the mode of oscillation may be determined by coupling to other circuits of the same type, and majority logic as described in United States Paten...