sisters and the blocking capacitors and substitute
ahigher gain vertical plug-in in place of the wide- band plug-in required for spike measurements. Notice that with these changes, Figure 5-7 be-
comes a two-cable version of Figure 5-6C.
5-34 Transient Recovery Time. Definition: The time “X” for output voltage recovery to within “Y” millivolts of the nominal output voltage following a “Z” Amp step change in load current - where: “Y” is specified as 10 millivolts. The nominal output voltage is defined as the dc level half way between the static output voltage before and after the imposed load change, and “Z” is the specified load current change, which is 5 Amperes.
5-35 A mercury-wetted relay, as connected in the load switching circuit of Figure 5-8 should be used for loading and unloading the supply. When this load switch is connected to a 60Hz ac input, the mercury-wetted relay will open and close 60 times per second. Adjustment of the 25K control permits adjustment of the duty cycle of the load current switching and reduction in jitter of the oscilloscope display.
5-36 The maximum load ratings listed in Figure
5-4must be observed in order to preserve the mer-
Figure 5-8. Transient Recovery Time, Test Setup
TM 11-6625-2965-14&P
cury-wetted relay contacts. Switching of larger load currents can be accomplished with mercury pool relays; with this technique fast rise times can still be obtained, but the large inertia of mercury pool relays limits the maximum repetition rate of load switching and makes the clear display of the transient recovery characteristic on an oscilloscope more difficult.
5-37 To check the transient recovery time of the supply, proceed as follows:
a . Connect test setup shown in Figure 5-8. b. Set METER switch to highest current
range and RANGE switch to lowest voltage mode. c, Turn on supply and adjust VOLTAGE con-
trols until front panel meter indicates exactly the maximum rated output current.
d. Close line on repetitive load switch set-
up.
e . Adjust 25
potentiometer until a stable display is obtained on oscilloscope. Waveform should be within the tolerances shown on Figure
5-9(output should return to within 10mV of original value in less than 50 microseconds).
Figure 5-9. Transient Recovery Time, Waveforms
5-38 OUTPUT IMPEDANCE
5-39 To check the output impedance, proceed as follows:
a . Connect test setup shown in Figure 5-10. b. Set METER switch to highest voltage
range.
c . Turn on supply and adjust VOLTAGE controls until front panel meter reads 20 Volts.
d. Set AMPLITUDE control on oscillator to 10 Volts (Ein), and FREQUENCY control to 100 Hz. e . Record voltage across output terminals of the power supply (Eo) as indicated on ac volt-
meter.
f. Calculate the output impedance by the
