Browse Prior Art Database

Variable Tone Oscillator

IP.com Disclosure Number: IPCOM000076502D
Original Publication Date: 1972-Mar-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Shakib, J: AUTHOR

Abstract

This oscillatory circuit is for an alarm or other type of attention signal and produces a warbling type of output. In effect, a slow-speed oscillator circuit is used to control the frequency of a higher frequency oscillator.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 61% of the total text.

Page 1 of 2

Variable Tone Oscillator

This oscillatory circuit is for an alarm or other type of attention signal and produces a warbling type of output. In effect, a slow-speed oscillator circuit is used to control the frequency of a higher frequency oscillator.

In the drawing, transistors 1 and 2 have their emitters connected to a common ground, and their collectors connected through individual resistances 3, 4 to a voltage source 5. Each collector is connected through its capacitor 6 to the base of the opposite transistor 1 or 2. Each base is given a turn-on bias, by a resistor 7 in parallel with a series pair of a transistor 8 and a resistor 9 connected between source and the base. With paired components, this circuit will generate at the output terminals a symmetric, generally square, waveform.

Another oscillator is provided to introduce into this oscillator a periodic variation, to distort the symmetric wave of the first oscillator and in turn change the frequency. This other oscillator is comprised of transistors 11 and 12 having their emitters connected to the common ground and with each collector connected through a resistor 13 to the voltage source 5, and through a capacitor 14 to the base of the other transistor 11 or 12. Each transistor base is also connected to voltage source 5 through a resistor 15 to provide the base with a turn-on bias. The components should be so chosen that this other oscillator will oscillate at a low frequency compared to that of the first...