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Negative Resistance Circuit

IP.com Disclosure Number: IPCOM000093734D
Original Publication Date: 1966-Jan-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Croisier, A: AUTHOR

Abstract

In many cases, it is necessary to compensate for network losses. Such compensation can be advantageously made through a negative resistance circuit. While there are various types of such resistors, the realization of the negative resistance element is easier when constant current sources can be used. In effect, when considering the usual negative resistor transistor assembly, should said transistors be fed through constant current sources, the resulting device does not present AC parallel losses. This is because there cannot be AC components through the current sources.

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Negative Resistance Circuit

In many cases, it is necessary to compensate for network losses. Such compensation can be advantageously made through a negative resistance circuit. While there are various types of such resistors, the realization of the negative resistance element is easier when constant current sources can be used. In effect, when considering the usual negative resistor transistor assembly, should said transistors be fed through constant current sources, the resulting device does not present AC parallel losses. This is because there cannot be AC components through the current sources.

This device concerns such an alternative in the case when a negative resistor is incorporated in a junction circuit, as for example, a junctor in an exchange system. The drawing shows a modified junctor. Transistors T3 and T4, previously used in the junctor before modification, are for marking path in the network and are represented to give an overall aspect of the junctor.

When point A is to be connected to point B, transistors T1 and T2 are activated, diodes D1 and D2 are conducting and the connection is performed for alternative current through the negative resistor. The negative resistance value is - R = - R6>1 + (2R6 + 2R7)/R3|. For DC, the resistance between points A and B is approximately R' = R6 + R7 + R8.

Due to the fact that the negative resistor circuit is fed by constant current through transistors T1 and T2, there are no AC parallel losses. The circuit do...