3.6M north10.pdf - Dean-O's Toy Box
3.6M north10.pdf - Dean-O's Toy Box
3.6M north10.pdf - Dean-O's Toy Box
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Cathode Pulsers Hard-Tube Modulators (10) 161<br />
When AVIV = 1, full discharge efficiency is 1/2, which we knew. For small perunit<br />
discharge-say, 0.1, or 107o droop+fficiency is 1- 1/2x 0.1 = 1-0.05 = 0.95,<br />
or 9570.<br />
In most high-power applications, however, resistance is not used between<br />
power supply and capacitor bank. Recharging current from the power supply is<br />
always limited by the equivalent ac series impedance of the power supply, most<br />
of which is the leakage reactance of the inductively coupled components, especially<br />
the high-voltage rectifier transformer.<br />
1.0<br />
I<br />
I 1 1 1 11111 A<br />
I I I I I IIIYI 1 I II 1 I 1 I I ml<br />
I<br />
10.4 Vacuum tubes as switch tubes<br />
Power grid vacuum tubes have numerous characteristics that define their<br />
total performance capabilities as pulse-modulator switching devices. The first<br />
characteristic of importance is peak-pulse power output, which is the product of<br />
the simultaneous maxima of load voltage and current that can be switched. Of<br />
course, the maximum load voltage is related to the continuous voltage that can<br />
be applied between anode and cathode of the tube while maintaining an accepta<br />
j = 0.5 Ncllf<br />
bj=l.olkn?<br />
cj=2.OA/cr#<br />
dj=5.o/VctTf<br />
e j= 10.ONW<br />
.01<br />
10 100 lC03<br />
Effecliv13peak drive voltage<br />
Figure 10-7. How cathode emission density is affected by spacing between grid and cathode (effect on<br />
perveance).