Theory of Operation—2213 Service
Capacitor C644 charges rapidly to the new voltage
difference through R642 to produce a very narrow pulse
output across R642. When the holdo ff period ends, the
Q output o f U640B goes HI again and C644 charges in the
opposite direction through VR644. The resulting A lt Sync
signal is applied to the Channel Switching circuit to syn
chronize the horizontal display w ith channel switching
transitions when using A L T V E R TIC A L MODE.
Delay Circuit
The Delay circuit, composed o f Q624, Q632, Q644,
Q650, Q652, U607D, and associated components, generates
the tim ing and gate signals required to produce the inten
sified Sweep display and to provide the variable Sweep
delay. H O R IZO N TAL MODE switch S650 controls the
display mode (NO D LY, INTENS, or D LY 'D ), and DELAY
TIM E switch S660 selects the basic delay time (0.2 ms,
10
ps, or 0.5
ms
). The D ELAY TIM E M ULTIPLIER
control (R658) increases the possible delay available by up
to at least twenty times the basic delay.
NO D LY. With H O RIZO NTAL MODE switch S650 set
to the NO D LY position, the Delay circuit is disabled and
the Sweep starts immediately after the Swp Gate signal is
produced by U603B at pin 9. Pin D o f S650 is open, so pins
4 and 10 o f U620 are pulled HI through R608. When the
Swp Gate occurs, pins 1, 2, 5, and 9 o f U620 all go HI.
The HI on pin 5 is ANDed w ith the HI on pin 4, and U620
pin 6 goes LO to initiate a Sweep. The output o f the Delay
circuit is disabled by grounding the base o f Q644 through
pin A o f S650. This action holds the Dly Gate signal at the
collector o f Q652 at a HI logic level. With the Dly Gate
signal HI, a HI is also gated through U620 to pin 8 to bias
o ff CR620. Diode CR622 is then forward biased to enable
the Intens Level current from R622 to the Z-Drive line to
unblank the c rt fo r the Sweep display.
INTENS. With S650 set to the INTENS position, the
Delay circuit is enabled. No delay in the Sweep occurs in
this mode, but an intensified zone is displayed. The amount
o f delay between the start o f the Sweep and the start o f
the intensified zone is determined by the D ELAY TIME
switch setting and the M ULTIPLIER control position.
The intensified zone is generated by gating through
U607D to control the Z-Axis gating diodes, CR619 and
CR621 (see Figure 3-6). Pin 12 o f U607D is pulled HI
through R607 as pin H o f S650 is open. When the delay
tim e has elapsed, U607D pin 13 is also switched HI (by the
Dly Gate signal), and pin 11 goes LO. Diode CR619
becomes reverse biased, and CR621 passes the Intens Level
current to the Z-Drive line. The extra current is added to
3 -1 8
@
Figure 3-6. Simplified diagram of the Z-Axis Switching Logic circuit.
Summary of Contents for 2213
Page 1: ...Ttektronix 2213 OSCILLOSCOPE SERVICE IN S T R U C T IO N M A N U A L ...
Page 9: ...2213 Service 3827 01 viii The 2213 Oscilloscope ...
Page 30: ...Theory of Operation 2213 Service 3 3 Figure 3 1 Basic block diagram of the 2213 Oscilloscope ...
Page 67: ...Adjustment Procedure 2213 Service 5 2 ...
Page 139: ...Figure 9 4 2213 block diagram S105 ...
Page 140: ...a o m 7 x C O o z CHANNEL SWITCH AND VERTICAL OUTPUT ...
Page 141: ...2213 Service ...
Page 144: ...2213 ...
Page 146: ...2213 3827 20 R V FB 4982 C 4 ...
Page 147: ...S90I 4 5 ...
Page 148: ...CIRCUIT BOARD INTERCONNECTIONS K tv ra n m CIRCUIT BO ARD IN T E R C O N N E C T IO N S ...
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Page 153: ...2213 3 K T i RtV D E C ...
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Page 155: ...2213 Service 1 3 a 7 ...
Page 161: ...2213 Service n 3 a ...
Page 168: ...s RE 2213 ...
Page 169: ... CH 1 CH 2 VERTICAL PREAMPS ...
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Page 177: ...TRIGGER ...
Page 180: ...fr ...
Page 181: ...f E V AUG I98Z SWEEP GENERATOR LOGIC ...
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Page 188: ...2 2 1 3 lAlO FWTW m ain b o a rd ...
Page 190: ...i _____H M N XY AMPLIFIER HORIZ OUTPUT ...
Page 191: ...A 1 1 C 1 a i F 1 G 1 H 1 3 4 5 6 7 HO COM TO P 4 C C O 5 S I i S2T 2e R EV Dec I9BI 2 2 3 ...
Page 203: ...2 2 1 3 Service R887 ASTIG R870 GEOM C784 5ns TIMING R860 GRID BIAS ...
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