DIY - The scheme of the analyzer state TTL output.

<b>DIY</b> - The scheme of the analyzer state TTL output.

     Analyzer state TTL output


   The scheme was designed to stand trial
Z80. However, for other chips, which
all 4 possible output states.

   I can not remember how the idea came about
determining the fourth state, which
outright and do not think ... This state of you
water when it is input. But apart from
direct inputs that all numbers
types is, in some complex chips such
inputs can be outputs. In this sense,
Recognition of such scheme is convenient mome
ntov. True, I have not tested it on "live"
representatives of such complex chips. And there
the likelihood that they (or some of
them) is identical to the state Z of the WMO
Yes. Then these chips 3 states, which
rye is not "0", "1" and "Z", and "0", "1" and "I"
(From the word IN).

   As we know, some series of inputs
implemented in field-effect transistors. And
some modern series too. In fact
a Z-state output, if it is nothing more
lshe not displaced. Of course, such an entry will be
defined as Z, and moreover, the very
circuit analyzer it certainly will shift /
switch to a state of logical "0" that
should be taken into account in ispolzovaniya.No
if no input field and the resulting demands
on the minus sign ("0") current, then surely it is not a QS
Jette switch to a state of logical
zero, the weighted input indicator (especially
especially the old and the rapid series). But it turned out
shis shifted to negative, it will be more chu
vstvitelen to interference, and it should be considered
work.

   2 keys are used on high
transistors with high gain amplification
leniya, thus requires a low current
logical unit or input for tripping
tion and display of these states. Thresholds
divisors defined bases of transistors.
Indication "0" included repeated emitter
accelerator, a key threshold, shifted
silicon diodes. Due to this the required
tsya weak current zero for its determination.

   Input impedance is, in fact,
to mitigate the steep fronts impu
lsov, and the input resistor must be maximal
mum close to schupu (or is it
part). One diode shunts the key - Indie
fication condition of entry if the level of acc
tstvuet logical edinitse.Drugoy helps
cover LED showing Z-state
of. This happens automatically, at
presence of currents on other svetodiodam.Oni Shun
green commute, so it has a lot to
voltage glow, plus the - bias
mapping / drop on diode.Rezistor prizakryvaet
base repeater to improve the detection
logical nulya.Ispolzovanie germanium
devices (their weak bias)
somewhat simplified scheme.



   As can be seen from the scheme, it uses metal
less than 1 mA. It is convenient to perform it in the form of 
Napa rstka (not your words - the size of the board) with three

batareykami.Togda name should be replaced by plu
cial 100 k to 75 k ohms, 100 ohms to exclude,
Capacitor (putting the switch), and the mind
nshit 3.3 ohms to 3 ohms. Crocodiles have
do not need ... Given the small time
measures of LEDs, it would be enough for 1 mA
home ... Germanium diodes can
zhno replaced by low-power Schottky, although I
have not seen weaker 1N5817, except that in with
quantum phones ... Germanium transistor
- In fact all except the oldest, the
which may still be less than the gain
said ... You should use light
diodes with these colors, either - someone with
obrazhaet - modify the scheme "for the UWC
su ", since it uses the difference
voltage glow in different colors of light
emitting diodes.

   This scheme can not be called serious, although
for studies of digital circuits and chips can
Jette useful. But to analyze the impu
lsny signal at the output is not normally
allow: a purely conventional ...


                        By KSA-7G 27.4.2007