transistor curve tracer - IC/UCE characteristics directly onto the screen

9-36 — elektor september 1980 transistor curve tracer B. Darnton The design Figure 1 gives the layout of a design which escaped notice in last year"s Summer Circuits "79 (no. 6). This is a cheaply constructed curve tracer for transistors and diodes. No really pro- fessional test instrument, of course, but an extremely useful aid to quickly carry out a general test either to compare transistors or select them. Naturally, hobbyists will have to have an oscillo- scope (with separate x and y inputs), because the curves will be displayed on the oscilloscope screen. Since it is impossible to tell which transistor characteristic is more import- ant than another, there is no such thing as the "most important curve". Transistor handbooks speak of the most read curve. to the Y input and the ground connec- tion of the oscilloscope "hangs" resistor R7. This is the TUT"s collector resistor and the voltage across it is naturally proportional to the collector current of the transistor tested. ...