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PG 505
PULSE GENERATO~i
TABLE OF CONTENTS
SECTION 1 OPERATING INSTRUCTIONS Page
I ntroduction 1-1
1 nstallation 1-1
Operating Considerations 1-2
Output Connections 1-2
Risetime and Falltime 1-2
Operating Modes 1-2
Normal 1-2
Output Locked On 1-2
External Duration 1-2
Output Delayed 1-2
Custom Period and Pulse Duration 1-3
Functions Available at Rear Connector 1-4
Definitions of Pulse Characteristics 1-4
Electrical Characteristics 1-5
Table 1-1 Output Signals 1-5
Table 1-2 Control Ranges 1-6
Table 1-3 Special Operating Modes 1-6
Table 1-4 Miscellaneous 1-7
Table 1-5 Environmental 1-7
SECTION 2 SERVICE INFORMATION
Symbols and Reference Designators 2-1
Electrical Parts List 2-2
Controls, Connectors & Rear Connector Pin Assignment
Adjustments (backside of foldoutl
Adjustments
Parts Location Grid & Theory of Operation
Diagram 1 (backside of foldout)
Delay Pickoff/Trigger Comparator, and
Period & Duration Generator 1
Theory of Operation
Diagram 2 (backside of foldoutl
Rise & Falltime, and Output Amplifier 2
Theory of Operation
Diagram 3 (backside of foldoutl
Power Supplies and Cam Switch Logic 3
Mechanical Parts List
Fig. 1 Exploded
Fig. 2 Accessories & Repackaging
OPTIONS
CHANGE INFORMATION
1
1
1
1
1
"1
1
1
1
1
1
1
PG 5q5
Section 1-PG 505
OPERATING
' INSTRUCTIONS
INTRODUCTION
The PG 505 Pulse Generator is designed to operate in a on the Power Module . Check that the POWER indicator on
TM 500 Series Power Module . The generator is a compact the PG 505 front panel comes on .
100 kHz, 80 V, general-purpose pulse generator. Controls
are provided for selection of a specific pulse period,
duration, risetime, falltime, amplitude and output polarity .
A special function control permits an output time with
relationship to a voltage level on an input ramp . A custom
position on the pulse period and pulse duration controls
permits a special pulse period and duration by adding
internal capacitors .
Installation
Turn the Power Module off before inserting the plug-
The PG 505 is calibrated and ready to use as received . in; otherwise, damage may occur to the plug-in
Referring to Fig. 1-1, install the Pulse Generator and turn circuitry.
Bottom
Groove
Fig . 1-1 . Plug-In installation and removal .
' REV . B, FEB . 197 5
Operating Instructions-PG 505
OPERATING CONSIDERATIONS
Output Connections 131-1012-00. The PG 505 may be ordered with this
connector factory installed by specifying Mod 818C.
The output of the PG 505 is designed to operate as a
voltage source through a 4 kSt load . Risetime and Falltime
Pulse characteristics can be preserved by observing the If the output pulse from the PG 505 is used for
following precautions : measuring the rise and falltime of a device, the risetime
characteristics of associated equipment may have to be
1 . Use high quality coaxial cables and connectors .
considered . If the risetime of the device under test is at
2. Make all connections tight and as short as possible . least 10 times longer than the combined risetimes of the
PG 505 plus the monitoring oscilloscope and associated
3. Use high quality attenuators, if necessary, to reduce
cables, the error introduced will not exceed 1% and
the pulse amplitude to sensitive circuits .
generally can be ignored. If the rise or falltime of the test
4. Use terminators or impedance matching devices to device, however, is less than 10 times as long as the
avoid reflections . combined risetimes of the testing system, the actual
5 . Ensure that attenuators, terminations, etc., have risetime of the device will have to be determined from the
adequate power handling capabilities for the output pulse . risetime of each component making up the system . This
Power output is determined by the duty factor of output equals the square root of the sum of the squares of the
pulse current. individual risetimes . Conversely, the risetime of the device
under test can be found from the same relationship if the
NOTE actual risetimes in the system are known, except that of the
device under test .
The PG 505 has been designed so that the output
BNC connector may be floated for floating-common
operation, remove the wire connecting the BNC shell If there is a DC voltage across the output load, the
to the ground lug located at the front bottom circuit output pulse amplitude will be compressed, or in some
board mounting screw. if the output is to be elevated cases, the output may be shortened . To prevent this from
to a dangerous potential, or if local safety regulations occuring, the output must be coupled through a DC
prohibit use of floating BNC connectors, replace the blocking capacitor to the load . The time constant, of the
BNC output connector. A suitable connector and coupling capacitor and load, must be long enough to
mating plug are the Tektronix 131-1011-00 and maintain pulse flatness .
OPERATING MODES
Normal External Duration
In the normal mode, the period generator free runs at When the PULSE DURATION switch is in the EXT
the rate selected by the PERIOD switch and VARIABLE DURATION position, the period generator is disabled . The
control. The duration of the output pulse (see Definitions output pulse is now turned on by applying a positiveyoing
of Pulse Characteristics) is selected by the PULSE DURA- signal greater than 2 V to the INPUT connector. The
TION switch and its associated VARIABLE control . Amp- output will turn on when the external signal amplitude goes
litude is set by the AMPLITUDE control. The pulse above about +2 V and turn off when the signal amplitude
polarity from a reference is selected by the + PULSE drops below about 2 V . The period and duration of the
push-push button . The PERIOD and PULSE DURATION output pulse is dependent on the period and duration of
selectors are mechanically coupled so the duty factor the external signal (see Fig. 1-2) .
cannot exceed 50% with the VARIABLE controls in the X1
position .
Output Delayed
The period generator is disabled when the PERIOD
Output Locked On switch is in the OUTPUT DELAYED position . The start of
When the PULSE DURATION selector is in the the pulse duration is controlled by picking a voltage point,
LOCKED ON position, the output remains locked at a DC with the OUTPUT DELAY control, on a 0 to +10 V ramp
level selected by the AMPLITUDE control and the + waveform connected via the INPUT connector . The dura- ,
PULSE push-push button (< 4 to 80 V) . tion of the output pulse is selected by the PULSE
REV . FEB 197 4
Operating Instructions-PG 505
DURATION switch and its associated VARIABLE control,
" while the period is dependent on the repetition rate of the
ramp (see Fig. 1-31 .
Duration variable with Amplitude variable
front-panel PULSE DURATION with front-panel
switch and associated VARIABLE AMPLITUDE con
' Custom Period and Pulse Duration controh trot . Polarity se-
lected by + PULSE
' A special I~ position is provided on the PERIOD push-push button .
and PULSE DURATION switches that provides a unique Risetime and fall-
time variable with
(custom selected) period and/or pulse duration . The elec 1 front-panel controls.
1
trical characteristics in this section define the period and 1 Output 1 Pulse
1 1 ~-~~~~~~~ +10 V
pulse duration limits . The location of the added capacitors
is shown in Fig . 1-4.
External Ramp Signal
Pickoff point
selected with
OUTPUT DELAY
control
, I II II
II II
li
I I ~ External
I j Pulses
I i I I
Fig. 1-3. Start of output pulse being controlled by selected pick-
off voltage point on ramp signal .
Output
Pulse
I , , I I I
1 I I
I
i j External
I I I Sinewave
v