Browse Prior Art Database

Crystal Controlled Blocking Oscillator

IP.com Disclosure Number: IPCOM000097870D
Original Publication Date: 1961-Aug-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Stankaitis, RF: AUTHOR

Abstract

In the circuit an NPN transistor 10 has its collector connected serially with winding 11 of a blocking transformer, the winding being shunted by diode D1. One electrode of D1 and one end of 11 are connected to a bias voltage supply V. Winding 12 of the transformer is shunted by a damping resistance R, one terminal providing an Output and the other terminal connecting to ground. The base of transistor 10 is connected serially through diode D2, a third winding 13 of the transformer and resistance RB to supply V. A capacitance C1 couples the common point of 13 and RB to ground. This circuit is a grounded emitter blocking 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 100% of the total text.

Page 1 of 2

Crystal Controlled Blocking Oscillator

In the circuit an NPN transistor 10 has its collector connected serially with winding 11 of a blocking transformer, the winding being shunted by diode D1. One electrode of D1 and one end of 11 are connected to a bias voltage supply V. Winding 12 of the transformer is shunted by a damping resistance R, one terminal providing an Output and the other terminal connecting to ground. The base of transistor 10 is connected serially through diode D2, a third winding 13 of the transformer and resistance RB to supply V. A capacitance C1 couples the common point of 13 and RB to ground. This circuit is a grounded emitter blocking oscillator.

A crystal of a natural frequency, corresponding to the normal operating frequency of the oscillator circuit, is connected from the anode of D2 to the Output for insuring performance stability of the oscillator.

In operation, upon initial generation of a signal at the Output, the crystal is stimulated into oscillation. Oscillation of the crystal imposes a negative voltage sine wave on the base of transistor 10 which, in conjunction with the C1 discharge signal, drives 10 to cutoff for the first half cycle. On the second half cycle 10 is driven to conduction.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]