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Circuits, as published and used by Elektor and the Dutch Elektuur, contain universal transistors and diodes to the abbreviations: TUP (Transistor Universal Pnp), TUN (Transistor Universal Npn), DUS (Diode Universal Silicon), and DUG (Diode Universal Germanium). Many transistors and diodes fit this way in these categories and makes component selection easier. Good system!


The minumum specifications have to be met, 

in Table 1a above, before you can call it a 

'TUP' or a 'TUN'.

The minumum specifications have to be met, in

Table 1b above, before you can call it a 'DUS' 

or a 'DUG'.
TUN/TUP Transistors

In the above tables, Table 2 and Table 3, you 

can use several different transistor types for a 

TUP or a TUN.  Obviously the tables are not 

complete.  It would be almost impossible to list 

all available transistor types available today.  

From the above listed types are all A, B, or C 

types usable.
DUS/DUG Diodes

Several different types of diodes are suitable

as a 'DUS' or 'DUG'.
Table 1a - TUN/TUP2

The most important parameters of the BC107...BC109 

and the BC177...BC179.  These transistors have been 

choosen as an example of information.
Case Outlines
The letter after the transistor indicates the hfe.  

Example: BC107A, hfe = 125 ... 260

         BC107B, hfe = 240 ... 500

         BC107C, hfe = 450 ... 900
Substitutes within the BC series of transistors are also possible. In Table 6 you see that the transisors are grouped in three. Example, the BC107, BC147, BC317 and BC413 can be substituted with each other, but a BC548 may not be exchanged for a BC107. Why? The BC548 is the second of a group of three. Your choice would be a BC547(A,B, or C).
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Copyright © 1996 - 2000 by Tony van Roon