.
-
134
6.
HIGH VACUUM, LOWVOLTAGE TUBES
—-=w—-<-=«w“—
'
_
l'l'l' + -
+
FIG. 6—_21.
The electron gun of a cathode-ray oscillograph.
noted that ultra—violet or infra—red rays may
be used as well as
visible light on the photoelectric surface. Short cylinder lenses are
—
used to focus the electrons upon a uorescent screen at the opposite
end of the tube, producing a sharply dened image of visible light.
EXPERIMENT 6—1
,_
CHARACTERISTIC CURVES OF TRIODES
'
The connections are shown in gure 6—22. Three circuits are
,
involved, the lament, plate and grid, supplied by the A
,
B, and C
batteries, respectively. It=is desired to study the various currents
.
'
:
_Ï' Ï3Ïi
«
=
'
‘
'
C
.
0…0D.C. "B”
Ï
 ]
.
+ |…
'
_
_FIG6—22Connectlons for obtaining the characteristic curves f
tubes.