Transistors and Junction Diodes in 

 Telephone Power Plants 



By F. H. CHASE, B. H. HAMILTON and D. H. SMITH 



(Manuscript received November 30, 1953) 



This paper describes the use of junction diodes, reference voltage diodes, 

 and junction transistors in regidated rectifiers for telephone power plants. 

 It discusses the pertinent characteristics of these semiconductor devices, 

 together ivith illustrative circuits in which they are used to control the flow 

 of direct current power. 



1. INTRODUCTION 



Recent articles in the literature have treated the theory and proper- 

 ties of semiconductor de\dces. In particular, papers by Messrs. Shockley, 

 Ryder, Wallace and others have emphasized the theoretical aspects of 

 the new devices; their reliability, reproducibility and performance at 

 high frequencies to name only a few.^' ^' ^- ^' ^ In addition many papers 

 have been published concerning their applications in the transmission 

 and computer fields. There is also a field of application for these devices 

 in the conversion and control of power, and this paper discusses some 

 of these power applications. 



1.1. Scope 



The first three groups of sections in this discussion review the perti- 

 nent characteristics and practical engineering aspects of junction recti- 

 fier diodes (Section 2.1), reference voltage diodes (Section 2.2) and junc- 

 tion transistors (Section 2.3). The second three groups of sections 

 concern respectively shunt transistor regulators (Section 3.1), series tran- 

 sistor regulators, (Section 3.2) and power regulating circuits employing 

 magnetic amplifiers in combination with transistors and junction diodes 

 (Section 3.3). The last two groups of sections treat specific appUcations 

 (Sections 4.1 through 4.3). 



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