LF: Tuesday's riddle (part 2)

["Rik Strobbe" <rik.strobbe@fys.kuleuven.ac.be>]

Hello Marcus,

very  interesting.
I did the experiment with a BC547c and as Andy I got a negative voltage.
While playing with it I reduced the voltage to +/- 5V and saw an even
more interesting effect, over a range of a few 10mV I got a nice sawtooth
signal. I wonder if someone can reproduce it ...

73, Rik  ON7YD

At 14:58 11/11/2002 -0500, you wrote:
> Hi group,
>
> this little experiment was pointed out to me by Ralph, DL2NDO a few years
> ago:
>
> You need an ordinary NPN transistor (eg. 2N2222), a 9V battery, a 1k
> resistor and a voltmeter. Connect the negative battery terminal to the
> base and the positive to the emitter, via the resistor. Now predict the
> voltage drop between collector and base. Can't be too hard...
>
> Then measure it - you'll be surprised. Any explanations? We finally ended
> up opening the poor transistor's case.
>
> Have fun
> Markus, DF6NM