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Circuit Description—455/A2/B2
Pin 9. Free run in. (Used on B sweep only.) Controls
the state of the Sweep Gate output at pin 10. When pin
9 is HI (STARTS AFTER D ELAY mode) pin 10 is LO.
When pin 9 is LO, the state o f pin 10 is controlled by
the state of pin 12 and/or the Trigger Input signal.
Pin 10. Sweep Gate out. Provides a Sweep Gate output
to trigger the sweep. When pin 10 goes LO the sweep
runs; when it goes HI the sweep is terminated.
Pin 11. Logic Gate out. (Used on A sweep only.) Pro
duces the same output as pin 10, except when pin 9 is
HI (STARTS AFTER D ELAY mode). The output at
pin 10 is not affected by the state of pin 9. This logic
gate output is used to initiate the Sweep Control 1C func
tions.
Pin 12. Reset in. The trigger is enabled through this pin.
When pin 12 is LO, pin 10 can be switched from HI to
LO by an adequate trigger signal which starts the sweep.
When pin 12 goes HI, pins 10 and 11 go HI, the sweep is
ended, and the trigger is reset.
Pin 13. Ground pin.
Pin 14. Not connected internally.
Pin 15. +5 volt supply.
Pin 16. Slope in. Connects to the SLOPE switch to
determine the slope (positive-going or negative-going)
from which the trigger signal at pin 2 produces a sweep
gate output.
+5 volts on pin 16 produces a + slope trigger output.
0 volts on pin 16 produces a — slope trigger output.
A TRIGGER GENERATOR. Basically, the A Trigger 1C,
U2700, accepts a selected trigger signal from the Trigger
Input circuit and produces a negative sweep gating pulse.
The + position of the SLOPE switch allows triggering on
positive-going trigger signals and the — position allows trig
gering on negative-going trigger signals. The LEVEL control
R2712 sets the voltage level, on the trigger signal, at which
triggering occurs. Trigger Level Centering adjustment
R2715 centers the adjustment range of the LEVEL control.
SLOPE
INPUT
TRIG
SIG
TRIG
LEVEL
TRIG VIEW OUT
RESET
FREERUN
GATE
OUT
LOGIC
GATE
OUT
1907-34
REV. A, O C T 1975
4-13
Fig. 4-5. Trigger 1C block functional block diagram.
Summary of Contents for 455
Page 1: ...Tektronix 455 A2 B2 PORTABLE OSCILLOSCOPE WITH OPTIONS I N S T R U C T I O N M A N U A L ...
Page 9: ......
Page 13: ...455 A2 B2 x 455 A2 B2 Portable Oscilloscope ...
Page 61: ...Circuit Description 455 A2 B2 Fig 4 4 Channel switching gates REV A OCT 1975 4 9 ...
Page 66: ...Fig 4 6 Sweep generator 1C Function block diagram Circuit Description 455 A2 B2 ...
Page 80: ...Maintenance 455 A2 B2 BOTTOM FRAME Fig 5 7 VO LTS DIV switch disassembly 5 8 REV A OCT 1975 ...
Page 90: ...Maintenance 455 A2 B2 Fig 5 13 Troubleshooting chart 5 18 REV A O CT 1975 ...
Page 91: ...Maintenance 455 A2 B2 1907 1 A Fig 5 13 Troubleshooting chart cont REV A OCT 1975 5 19 ...
Page 132: ...Instrument Options 455 A2 B2 Option 7 Page 8 REV E AUG 1979 D C TO AC I NVERTER ...
Page 166: ...l 07 7 REV b NOV C M1 4 5 5 MAIN MODULE BLOCK DIAGRAM ...
Page 167: ...4 5 5 A 2 B 2 AS VERTICAL MODULE IR07 R8 RE V B M O ...
Page 168: ...I S 0 7 9 8 R E V B NOV IRT7 A2 VERTICAL MODULE BLOCK DIAGRAM ...
Page 169: ...REV B NOV 1977 Fig 9 2 A1 Partial Interface board compo ...
Page 170: ...455 A2 B2 Sea Parts List for serial number ranges tial Interface board component locations ...
Page 173: ...v I m B 2 HORIZONTAL MODULE BLOCK DIAGRAM ...
Page 174: ...455 A2 B2 REV B NOV 1977 Fig 9 3 A 1 Partial Interface board component locations ...
Page 182: ...455 A2 B2 Fig 9 4 A20 Vertical board component locations SN B0110 ...
Page 185: ...455 A2 S2 4 5 5 M A fN M O DULE ...
Page 187: ...455 A2 B2 Fig 9 5 A20 Vertical board component location SN B010100 B REV C NOV 1977 ...
Page 191: ...V O L T S 01 ...
Page 192: ...V O LT S Q IV S H O W N IN 57 H V ...
Page 198: ... U 1 X SlCjMAt TO P2 A4 h o p it MODULE SEE PARTS LIST FOR SEMICONDUCTOR TYPES f SWITCHING ...
Page 207: ...A 1 4 B T I M I N G S W I T C H B O A R D A13 A TIM ING SWITCH BOARD 1 9 0 7 3 ...
Page 209: ...4 5 5 A 2 B 2 B 2 h o r iz o n t a l m o d u l e R o i I 11 R E V C NOV IS77 ...
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Page 214: ......
Page 216: ...A B T IM IN G S W IT C H INTERFACE C O N N E C T O R ...
Page 223: ... ...
Page 224: ...455 A 2 B 2 ...
Page 225: ... 455 A2 B2 ...
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Page 233: ......
Page 234: ...455 A2 B2 ...