The CHARACTERISTIC CURVE for an electron tube is a graphic plot of plate current (Ip) versus
plate voltage (Ep). From this, dc plate resistance can be computed by the formula:
FACTORS THAT LIMIT VACUUM TUBE OPERATION are plate dissipation, maximum
average current, maximum peak-plate current, and peak-inverse voltage.
DIODE RECTIFIERS take advantage of the fact that diodes will conduct in only one direction.
When ac voltages are applied to diodes, conduction occurs only on the alternation that makes the plate
positive relative to the cathode. Because of this, the output current consists of one polarity. Because it
flows in pulses rather than continuously, it is called pulsating dc.
DIODE CONSTRUCTION is the basic construction plan of most vacuum tubes. The tube is
constructed of the following parts: filament and/or cathodes, plates, envelope, and base.