Browse Prior Art Database

Pulse Generator

IP.com Disclosure Number: IPCOM000095896D
Original Publication Date: 1964-Sep-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

Retter, EF: AUTHOR

Abstract

The circuit effects the generation of a pulse train without resort to the use of inductive components.

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Pulse Generator

The circuit effects the generation of a pulse train without resort to the use of inductive components.

NPN transistor 10 has its emitter directly connected to the emitter of PNP transistor 11. The base of transistor 10 is coupled to the collector of transistor 11 via capacitance 12. Positive bias +V is provided through resistance 13 to the collector of transistor 10 and to the base of the same transistor by resistance 14. Negative bias voltage -V is applied to the collector of transistor 11 through resistance 15 with the base of this transistor thresholded to ground. The pulse train output E is taken from the common point of collector to transistor 10 and resistance 13.

In operation, when the bias voltages are initially applied, both transistors are in the non-conductive state. Capacitance 12 receives charging current through resistances 14 and 15 bringing the base of transistor 10 to a sufficiently positive condition as to induce conduction through both transistors. A first sharply negative output pulse E is now obtained with positive feedback through capacitance 12, driving both transistors into saturation. Capacitance 12 then discharges through the base-emitter junctions of the transistors until it can no longer sustain saturating current. As transistor 10 again becomes non- conductive, a second negative output pulse of current is transmitted through capacitance 12 to the base of transistor 10 turning it off, which at the same time turns off tr...