1152 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1953 



-16 



-12 



20 



B -4 4 8 12 l( 



INPUT, El, IN VOLTS 



Fig. 11 — Switching type diode gate output potential versus control potential 

 with a second control in the "enable" state. 



SPECIAL CIRCUIT 



It is not intended, in this paper, to attempt to list the numerous modi- 

 fications which have been made of diode gates to overcome limitations 

 and satisfy particular requirements, but it seems desirable to note an 

 example of means to minimize the limitations. 



One simple way of minimizing the difficulty, is to use point contact 

 diodes in places where a spurious pulse could make trouble and use 

 junction diodes elsewhere, since junction diodes have better impedance 

 ratios but worse hole storage. For example, the output diodes in the 

 switching gate could be a point contact unit, while the better discrimina- 

 tion of the junction unit made use of for control diodes. 



A second means of avoiding hole storage effects is to avoid leaving 

 diodes with large currents flowing in them, when they must be switched 

 rapidly to the non-conducting state. 



