TM 9-6625-474-14&P-3
operate as TTL to ECL level shifters. As the first clock
pulse on pin 5 of U1300A makes a transition from low to
high, the output (pin 2) goes from low to high, Assuming
that the first decade counter has also been reset, pins 9, 10,
and 11 of U1300B are all low with its output (pin 7) also
low. This low on pin 7 allows the first clock pulse to pass
through U1330A. If the instrument is operating in the
mode, pin 5 of U1320A is held low. This ensures that the
counters do not advance or change their “nines” state,
allowing all of the succeeding clock edges to pass through
U1300A.
For the
10 mode, pin 5 of U1320A is no longer held
low and the first decade counter is no longer held reset.
The first clock edge on pin 6 of U1310A passes on through
U1300A. The first clock transition has also caused U1310A
to change state, setting pin 9 of U1300B high. The output
of U1300B and the wired-OR junction goes high and
remains high for the next ten clock edges. After ten
counts, the first decade counter is back to its original state,
setting all three inputs to U1300B low. This causes the
wired-OR junction to go low, allowing the eleventh clock
edge to pass through U1300A. Thus, the first and eleventh
clock edges causes the N Output to go high.
The reason that the decade count does not continue
past the first decade is that pin 5 of U1510B is held low and
pin 6 of U1400
IS
held high. For N =
(100) pin 4 of
U1401 is held reset (set to nine), but the first decade
c o u n t e r a n d U 1 4 0 0 a r e i n v o l v e d i n t h e c o u n t d o w n
process. The first clock edge through U1300A causes the
N Output to go high, and the 101st edge does the same.
The second through one-hundredth clock edges are
suppressed via the wired-OR junction and because the
output of U1400 is changing, this keeps U1300A disabled
until the 101st clock edge occurs.
In any of the averaging modes (PERIOD B, WIDTH B,
T I M E
B, EVENTS A DUR B, or RATlO A/B) and
N = 10, it requires eleven periods of the selected mode to
count ten periods. The first clock edge on pin 6 of U1310A
advances the first decade counter, but it
IS
desired to hold
off the first clock edge out of the
N Circuit. Instead of
setting pins 9, 10, and 11 of U1300B all low at reset (clear)
for the averaging modes, pins 10 and 11 areset lowand pin
9 high; the first flip-flop, U1310A is set rather than reset.
Anytime that the instrument is in an averaging mode and
pin 5 of U1320A is not held low (N = 1), U1310A is set by
the clear pulse via U1300C.
In the TOTALIZE A mode the
N Circuit and the
internal Time Base are not used. In the TIME MANUAL
mode, the Time Base signal is divided by N. In both modes
the gate
IS
generated by the START/STOP switch input to
CR1222.
For all modes except TOTALIZE A and TIME MANUAL,
the input to pin 3 of U1600B is at a high level. This causes
CR1220 to be forward biased, holding pin 9 of U1310A low
and enabling that flip-flop to change state when clocked
o n p i n 6 , W h e n t h e i n s t r u m e n t i s o p e r a t i n g i n t h e
TOTALIZE A or TIME MANUAL mode, pin 3 of U1600B is
held low, reverse biasing CR1220 and allowing the clock
input to U1310A to be enabled and disabled by the
START/STOP switch.
Also, for the TIME MANUAL and TOTALIZE A modes
when the instrument is not dividing by one (N = 1), pins 12
and 13 of U1430D are both low. These low levels enable
U1220D and disables U1320B. When the circuit is cleared
by the ECL CLR signal on pin 5 of U1220D, U1411A
becomes set, rather than reset; U1411A is normally reset
for the other modes. This action also produces a small
hold off interval for the TIME MANUAL mode; the first
clock edge does not start the Gate Generator via U1300A.
It takes at least two counts to get the Measurement Gate
started in the TIME MANUAL mode.
Measurement Cycle Timing
N O T E
Refer to Signal Routing and Gate Generator (FRE-
QUENCY A) discussion for a description of the
circuit that generates the Latch Trigger signal. Also.
see Fig. 3-1 for a typical timing diagram.
The Latch Trigger signal on P1630-1 (J1630-1) makesa
positive transition when the Measurement Gate is ter-
minated. Gate termination is indicated when a negative
transition occurs on pin 3 of U1420A. The Latch Trigger
signal goes to two places: pin 12 of U1423B and pin 11 of
U1420D; therefore, two things are going to happen.
The negative transition on pin 13 of U1420D turns off
Q1400, allowing C1400 to start charging toward
V
through R1400, R1401, R1410, and the DISPLAY TIME
switch, S1410. This produces a rising ramp voltage
interval on the emitter of Q1300. Also, when triggered on
pin 12, the one-shot multivibrator (U1423B) generates a
positive pulse of approximately 50 ms duration on pin 10.
The multi vibrator, along with U1420A, operate as a pulse
stretcher circuit. Thenegative pulse out of pin 1 of U1420A
causes the GATE light on the front panel to be illuminated
during the active gating interval.
Pin 9 of U1423B also goes low when them ultivibratoris
triggered. Assuming that the RESET line is high, U1422D
is enabled via pin 13. The rising edge on pin 12 of U1422D
happens about 50 ms later and translates to a falling edge
on pin 5 of U1423A, another one-shot multi vibrator. When
U1423A is triggered by the falling edge on pin 5, a Load
pulse (microseconds duration) is transmitted via U1422B
Содержание DC503a
Страница 1: ...e x _ 1 v w W i L ...
Страница 16: ...DC 503A DC 503A Universal Counter Timer REV A FEB 1981 XIV ...
Страница 27: ...Fig 2 2 Controls and connectors Operating Instructions DC 503A 2977 fli English 2 3 ...
Страница 39: ...Fig 2 2 Commandes et prises Instructions d utilisation DC 503A French 2 3 ...
Страница 51: ...Abb 2 2 Bedienungselemente and Anschliisse Bedienungsanleitung DC 503A German 2 3 ...
Страница 63: ...Fig 2 2 Controls and connectors Operating Instructions DC 503A 2971 01 Japanese 2 3 ...
Страница 125: ...Fig 8 2 Auxiliary Board A12 Assy ADJUSTMENT LOCA 2971 1 6 ...
Страница 169: ...SEE END OF MPL FOR WIRE ASSEMBLIES O1 0 pG C 0 DC 503A ...
Страница 186: ...0 2 TM 9 6625 474 14 P 3 Fig 0 1 DC 503A Universal Counter Timer ...
Страница 188: ...Table 1 1 1 2 TM 9 6625 474 14 P 3 ...
Страница 189: ...Table 1 1 1 3 TM 9 6625 474 14 P 3 ...
Страница 190: ...Table 1 1 1 4 TM 9 6625 474 14 P 3 ...
Страница 191: ...Table 1 1 1 5 TM 9 6625 474 14 P 3 ...
Страница 192: ...1 6 Table 1 1 TM 9 6625 474 14 P 3 ...
Страница 193: ...Table 1 1 1 7 Table 1 2 Table 1 3 TM 9 6625 474 14 P 3 ...
Страница 194: ...Table 1 3 Table 1 4 1 8 TM 9 6625 474 14 P 3 ...
Страница 197: ...2 3 TM 9 6625 474 14 P 3 Fig 2 2 Controls and connectors ...
Страница 211: ...3 5 Fig 3 1 TM 9 6625 474 14 P 3 ...
Страница 219: ...4 2 TM 9 6625 474 14 P 3 Table 4 1 LIST OF TEST EQUIPMENT REQUIREMENTS ...
Страница 240: ...5 7 TM 9 6625 474 14 P 3 Fig 5 9 Rear interface connector assignments ...
Страница 256: ...8 3 8 4 blank TM 9 6625 474 14 P 3 ...
Страница 257: ...8 5 8 6 blank TM 9 6625 474 14 P 3 ...
Страница 258: ...Fig 8 2 Fig 8 1 8 7 8 8 blank TM 9 6625 474 14 P 3 ADJUSTMENT LOCATIONS ...
Страница 259: ...8 9 8 10 blank TM 9 6625 474 14 P 3 PARTS LOCATION GRID Table 8 1 COMPONENT REFERENCE CHART See Fig 8 3 ...
Страница 260: ...TM 9 6625 474 14 P 3 8 11 8 12 blank ...
Страница 261: ...Fig 8 4 8 13 8 14 blank TM 9 6625 474 14 P 3 Table 8 2 COMPONENT REFERENCE CHART See Fig 8 4 PARTS LOCATION GRID ...
Страница 262: ...TM 9 6625 474 14 P 3 8 15 8 16 blank ...
Страница 263: ...8 17 8 18 blank TM 9 6625 474 14 P 3 Table 8 3 COMPONENT REFERENCE CHART See Fig 8 3 ...
Страница 264: ...8 19 8 20 blank TM 9 6625 474 14 P 3 ...
Страница 265: ...8 21 8 22 blank TM 9 6625 474 14 P 3 Table 8 4 COMPONENT REFERENCE CHART See Fig 8 3 ...
Страница 266: ...8 23 8 24 blank TM 9 6625 474 14 P 3 ...
Страница 267: ...8 25 8 26 blank TM 9 6625 474 14 P 3 DC 503A Table 8 5 COMPONENT REFERENCE CHART See Fig 8 4 ...
Страница 268: ...8 27 8 28 blank TM 9 6625 474 14 P 3 ...
Страница 269: ...8 29 8 30 blank TM 9 6625 474 14 P 3 DC 503A Table 8 6 COMPONENT REFERENCE CHART See Fig 8 3 ...
Страница 270: ...8 31 8 32 blank TM 9 6625 474 14 P 3 ...
Страница 271: ...8 33 8 34 blank TM 9 6625 474 14 P 3 DC 503A Table 8 7 COMPONENT REFERENCE CHART See Fig 8 4 ...
Страница 272: ...8 35 8 36 blank TM 9 6625 474 14 P 3 ...
Страница 273: ...Fig 8 5 8 37 8 38 blank DC 503A TM 9 6625 474 14 P 3 PARTS LOCATION GRID Table 8 8 COMPONENT REFERENCE CHART ...
Страница 274: ...8 39 8 40 blank TM 9 6625 474 14 P 3 ...
Страница 275: ...8 41 8 42 blank TM 9 6625 474 14 P 3 DC 503A Table 8 9 COMPONENT REFERENCE CHART See Fig 8 3 ...
Страница 276: ...8 43 8 44 blank TM 9 6625 474 14 P 3 ...
Страница 277: ...8 45 8 46 blank TM 9 6625 474 14 P 3 DC 503A Table 8 10 COMPONENT REFERENCE CHART See Fig 8 4 ...
Страница 278: ...8 47 8 48 blank TM 9 6625 474 14 P 3 ...
Страница 291: ...D 1 TM 9 6625 474 14 P 3 APPENDIX D MANUAL CHANGE INFORMATION ...
Страница 292: ...D 2 TM 9 6625 474 14 P 3 ...
Страница 293: ...D 3 TM 9 6625 474 14 P 3 P a g e 1 o f 2 ...
Страница 294: ...Page 2 D 4 TM 9 6625 474 14 P 3 ...
Страница 296: ...D 6 TM 9 6625 474 14 P 3 ...
Страница 298: ......
Страница 299: ...THE METRIC SYSTEM AND EQUIVALENTS ...
Страница 300: ...PIN 056816 000 ...