TM11-6625-2948-14+P
2J1. The Schmitt trigger circuit composed of 2Q8 and 2Q9
to 20,000 pps. The actual rate will depend upon the setting
is a dc coupled amplifier used to improve the rise and fall
of front panel RATE control R5. When the RATE X1-
time of the input waveform. 2Q10 is an emitter follower
X10-X100 switch is placed in its X1 position the repetition
used to provide a low output impedance for the circuit.
rate will be in the range of 20-200 pps due to the addition
A positive going signal will provide a positive going signal
of 2C1 which increases the charging time constant in the
at the emitter of 2Q9. The Schmitt trigger provides two
u n i j u n c t i o n emitter circuit. 2Q23 is a feedback current
outputs; a square wave which is direct coupled through the
source which linearizes the sweep. As the capacitive com-
FUNCTION switch, when it is in its EXT
posi-
ponents charge in the emitter circuit a positive going
sawtooth waveform is developed. When the firing poten-
tion, to the
output amplifier. The other output is
differentiated by 2C16 and 2R38 and routed to the pulse
tial is reached at the emitter, 2Q1 turns on and allows the
generator for pulse shaping and delay.
capacitive components to discharge through 2R2 and 2L1
creating sharp positive pulses across 2R2 and 2L1. These
d. Pulse Generator 2IC1, 2IC2. The pulse generator consists
pulses are fed to the 2 Flip/Flop which divides the input
pulses in half to develop the output repetition rates of 10
to 10,000 pps. When the FUNCTION switch is placed in
2IC2. As the integrated circuits are connected, they require
its FM position additional capacitive components are added
a positive going signal to activate the output. The positive
to the emitter charging circuit. The components are 2C7,
going output of the Schmitt trigger used to initiate pulse
2C8, and 2C9, in the RATE X1-X10-X100 positions respec-
generation is differentiated by 2C16 and 2R38 and applied
tively. No division takes place in this mode of operation
to the input of 2IC1. The pulse output of 2IC1 is a negative
and the rates developed are the output rates. The sawtooth
going waveform whose duration is determined by 2C17,
waveform developed in the 2Q1 emitter circuit is fed to
2C18, 2C38 or 2C39, 2C40 and the front panel SYNC
the sawtooth amplifier for further processing. 2R6 in the
DELAY controls 2R41 and 2S4. The output pulse of 2IC1
2Q1 emitter circuit is adjusted in conjunction with 2R5 to
is differentiated by 2C19 and 2R42, the leading or negative
provide the high repetition rate which is approximately
going edge is routed to the undelayed sync amp while the
10,000 pps. When the selector switch is placed in the
positive going edge, which represents the fall of the pulse
external positions, an external positive signal (selector set
developed by 2IC1, is connected to the input of 2IC2.
to EXT(+)), an external negative signal (selector set to
The positive input to 2IC2 initiates pulse generation by
EXT(-)), or a sinewave may be used to synchronize the
2IC2 which is a positive going waveform whose duration is
sawtooth waveform. This is performed by transistor 2Q22.
the output pulse width determined by 2C36, 2C37, 2C48
2Q22 is turned on by the undelayed signal pulse. This
or 2C49/C50 and PULSE WIDTH, 2R76 and 2S7. The
causes the unijunction transistor 2Q1 to fire.
duration of the pulse generated by 2IC1 therefore repre-
sents the delay time between the undelayed sync pulse and
b.
2 Flip/Flop 2Q2, 2Q3. The 2 Flip/Flop accepts the
the output delayed sync pulse. The leading edge of the
positive going pulses from the rate generator, in the range
output pulse and the delayed sync pulse are coincident.
of 20-20,000 pps, and produces a square wave at the
e. Undelayed Sync Amp 2Q14, 2Q15, 2Q16. T h e
collector of 2Q3, at the output rate of 10-10,000 Hz. The
square wave is routed through the FUNCTION switch to
undelayed sync amplifier input transistor 2Q14, a pnp type,
t h e INT position of the SELECTOR switch 2S3. When
is quiescently cut off. The negative going pulse from the
the SELECTOR switch is in the INT position the square
differentiating network of 2C19 and 2R42 causes 2Q14 to
w a v e is fed to the Schmitt trigger circuit for further
conduct allowing the collector to go positive causing 2Q15
processing.
to conduct dropping its collector to ground potential.
When the collector of 2Q15 assumes its low potential state
c. Schmitt Trigger 2Q8, 2Q9, 2Q10. The input to the
2Q16 conducts allowing its collector to go positive and
Schmitt trigger is determined by the position of the
somewhat less than +32 volts. The collector of 2Q16 is
SELECTOR switch. When the SELECTOR switch is in its
connected to the UNDELAYED SYNC OUT connector 2J3
INT position, a square wave from the 2 Flip/Flop is
through 2R73.
applied to the input. When the SELECTOR switch is in
f. Delayed Sync Amp 2Q11, 2Q12, 2Q13. The delayed
its EXT - or EXT + position the output of the ext sig
amplifier will be applied to the input. The output wave-
sync amplifier input transistor 2Q11, an npn type, is quies-
form of the ext sig amplifier will depend upon the type
cently cut off. The positive going pulse from the differen-
of signal waveform connected to the EXT SYNC connector
tiating network of 2C25 and 2R57 causes 2Q11 to conduct
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