EG&G ORTEC 416 Manual de instruções - Página 11

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6 - 1

6. MAINTENANCE INSTRUCTIONS

6.1 Testing Performance

To test the operation of this unit, first test the operation of the delay multi

vibrator section. To do this, merely insert on input trigger pulse and check

for on output from the DELAY PERIOD output. Monitor the width of the

DELAY PERIOD output, vary the delay potentiometer, R11, through its range,

and also check the operation of the RANGE SELECTOR switch, SI. Of

course, this pulse width should be equal to the desired delay time except for

a small propagation delay of about 25 nanoseconds. With the trigger present,

if there is no DELAY PERIOD output, the trouble is immediately isolated to

the delay multivibrator. Usually the first test to perform is that of measuring

dc voltages and comparing them with the voltages given in Table 1. If this

does not isolate the trouble, then one must resort to the use of on oscilloscope

and waveform checks. Sufficient waveforms for comparison ore given on the

schematic diagram, drawing number 416-001-51, in the back of the manual.

If the DELAY PERIOD output pulse is present, check for on output from the

DELAYED MARKER output BNC. If the DELAYED MARKER output does not

exist, then the problem is immediately isolated to the circuit surrounding Q6.

If a DELAYED AAARKER output exists but there is no gate pulse output, this of

course indicates that the gate multivibrator is not being correctly triggered.

Again, the best test is a dc voltage measurement test and comparison against

the tabulated voltages.

6.2 Calibration Adjustments

There ore no calibration adjustments in the Gate and Delay Generator itself;

only the adjustments which are available at the front panel are variable.

DELAY

PERIOD

\Z3-^y.

DELAY

J MARKER

OATL

GEN.

PULSE

GEN.

^ (i) delay

v.^-\ [ ^marker

DELAYED

OA-4m sec

® i_jfp

Figure 6-1. Gate and Delay Generator - Block Diagram