[sdiy] Saw core JFET mystery

[René Schmitz]

Have you observed the voltage at the integrators -input node? Just to 
see that it truely stays at GND.

David G. Dixon schrieb:
>> A drawing would help.
> 
> Here's an attempt.  Note that the comparator's ground pin (pin 1) is
> connected to -15V (not shown).  The Franco resistor is the 680R one.  The 1k
> resistor and 22pF cap are the reset timing components.
> 
>           Integrator             Comparator
> 
>                                     22pF 
>                    Saw           ----||----
>               |\    ^            |        |
>         GND---|+\   |     1k     | |\     |
>               |  \__|___/\/\/\___|_|+\    |
> Expo I ->-----|- /  |              |  \___|
>            |  | /   |            __|- /   |
>            |  |/    \            | | /    |
>            |        / 680R       | |/     |
>            |        \           _|_       |
>            |  1nF   |           +5V       |
>            ----||----                     |
>            |        |                     |
>            | PN4391 |                     |
>            |_     __|                     |
>              |___|                        |
>                ^                          |
>                |__________________________|
>                                           |
>                                           \
>                                           / 2.2k
>                                           \
>                                          _|_
>                                          GND
> 


-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159