When a tube is used as a Class B amplifier...

Question 1 / 27070vGzAX6EKACTBAaEvtHcw

Question 1 of 27070vGzAX6EKACTBAaEvtHcw

When a tube is used as a Class B amplifier what portion of the excitation voltage cycle does plate current flow?

Question 1 of 27070

When a tube is used as a Class B amplifier what portion of the excitation voltage cycle does plate current flow?

🔍 Key Concepts

• Amplifier classes (A, B, AB, C) and how they differ in conduction angle • Definition of conduction angle in degrees of the input signal cycle • Relationship between efficiency and portion of the cycle during which plate current flows

💭 Think About

• Compare Class A, Class B, and Class C operation: over how many degrees of the input cycle does current flow in each? • Think about whether Class B is exactly half the cycle, more than half, or less than half, compared with Class A (full cycle) and Class C (small portion). • Recall where Class AB fits in relative to Class A and B, and use that to narrow down what pure Class B must be.

✅ Before You Answer

• Be clear on that Class A conducts for the entire cycle (all 360°) of excitation. • Know that Class C conducts for much less than half of the cycle. • Use Class AB (between A and B) and Class C (far below 180°) to pinpoint what pure Class B must correspond to in degrees.

Question 1 of 27070

When a tube is used as a Class B amplifier what portion of the excitation voltage cycle does plate current flow?

Slightly more than 180 degrees

Slightly less than 180 degrees

360 degrees

None of the above