Re: Trying to understand how to design circuits



Tim Williams wrote:

Now on the other hand, you might have something like this:
http://webpages.charter.net/dawill/Images/Frequency%20Divider.gif
I'll help you out.  Each pair of transistors (in the circles) facing each
other works together: when one or the other is turned on (positive voltage
on the straight line), the collector (diagonal line) is pulled down near
emitter (diagonal arrow).  Say you pull down the upper-left collector node:
the voltage is transferred through the resistors, removing voltage from the
inside upper-right transistor.  If the outside upper-right transistor is off
too, then the collector node will rise near +V, which puts voltage on the
inside upper-left transistor -- which you'll recall is already on, holding
its collector near zero (ground).  Thus, it holds itself in one state or the
other depending on which input was last triggered, otherwise known as a
register.  But there's those other resistors that connect to the diodes,
which then connect to the bottom half register, which behaves in the same
way, and also to the two transistors at the bottom.  The two bottom
transistors handle the only input.

What ends up happening is, by way of everything storing, interacting and
switching, the P1 and P2 signals alternate every other clock pulse, which is
to say the clock frequency has been divided by two.



Could you have picked a more complicated example? No one in their right mind would look at that archaic thing as an elemental building block from a circuits point of view. You might have explained its decomposition into more fundamental component circuits.

.

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