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NOTES TO SCHEMATIC SECTION
Certain conventions have been observed in preparing
schematics for this manual:
1.
TIesistor values are given in ohms.
If
wattage
is unspecified the resistor may be either 1/40r.
1/2 watt.
2.
Capacitor values may be given in picofarads or
microfarads.
Those values for which neither
designation is provided are assumed to be ob-
vious from circuit function.
Filter capacitors
on certain supply lines do not have logic Signifi-
cance. In general, they are not shown on sche-
matics. On PC board silkscreens they are des-
ignated as CF.
3.
Normally, IC power connections are on pins 14
(+5v) and 7 (ground) for 14 pin packages, and 16
(+5v) and 8 (ground) for 16 pin packages. Some
ICs -7476, 7492, 7493 for example - have power
connections on pin 5 (+5v) and pin 10 (ground).
- Operational amplifiers in the 8 pin package have
power
.:~onnections
on pin 4 (- Vcc) and pin 7
(+Vce)~f
Power connections are not shown unless
they are nonstandard.
4.
Where multiple inputs are tied together only one
pin may be designated on the schematic.
5.
Unused inputs that are tied high are not normally
indicated unless the connection has logic signifi-
cance.
6.
From and to designations are intended to describe
inputs and outputs only. The same signal may
be connected to several other points not shown
on a particular drawing.
7.
Abbreviations used in from and to designations
are as follows:
CI
PBC
RG
SA
DT
RA/CL
RA
WA1
WA2
Control Interface
Pushbutton Control
Ramp Generator
Sensor Amplifier/Driver
Delay Timing
Read Amplifier/Clipping Level
Quad Read Amplifier
Four Channel Write Amplifier
Five Channel Write Amplifier
6-3
8. Positive logic is shown for all internal connec-
tions.
Interface connections are zero true but
the bar is omitted.
n.
Integrated circuit symbols contain a circuit
deSignator that corresponds to the number silk-
screened onto the eircuit module above an under-
lined number representing the
Ie
type.
The
Ie
type number is abbreviated and omits
the portions of the manufacturer's type number
pertaining to case and vendor identification.
Further, since the TTL 7400 series makes up
most of the circuitry, the 7
-t
is omitted on these.
Thus a 00 deSignation indicates a 7
-tOO
quad two
input NAND gate. T. I. 's complete part number
is SN7 400N.
In multifunctional units in close
proximity to each other the type designation may
be omitted. The type deSignation may appear
outside the symbol if the symbol is too small.
l\lilitary Standard 80Ge is the base for logic
symbols. Additional conventions are shown be-
low.
~i~~ver
Line indicates open collector
Triangle indi-
cates response
to edge (in this
case positive)
PR
10. Semiconductor types on schematics may be re-
placed by their functional equivalents.· If not
indicated, diodes are 1N914, NPN transistors
are 2N2714, and PNP transistors are MPS6517.
11. Unless otherwise specified, light emitting diodes
are FLV102 or equivalent.
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