Describing BatMod Operating

Some operating points (lines) labeled a, b, c, d, e, f in the 12V output BatMod operating area

Descriptions:
1. Constant current mode, Ru > 0 ohms and is finite; Rd > 0 ohms and is infinite.
2. Constant voltage mode, Ru > 0 ohms and is finite; Rd > 0 ohms and is infinite.
3. Constant voltage mode, Ru > 0 ohms and is infinite; Rd > 0 ohms and is finite.
4. Constant current mode, Ru > 0 ohms and is infinite; Rd > 0 ohms and is finite.
5. Constant current mode, Ru > 0 ohms and is infinite; Rd > 0 ohms and is infinite.
6. Constant voltage mode, Ru > 0 ohms and is infinite; Rd > 0 ohms and is infinite.
7. Constant voltage mode, Ru is OPEN; Rd is OPEN.
8. Constant current mode, Ru is SHORTED; Rd is SHORTED.
9. Constant current mode, Ru is OPEN; Rd is SHORTED.
10. Constant voltage mode, Ru is SHORTED; Rd is OPEN.

Match the symbols a, b, c, d, e, f shown in the graphs above to the 1-10 descriptions for making the best sense. Mark symbol "X" to an improper description if any, and email your answers to vicorhk@vicr.com with 'Quiz7' as the subject no later than July 1st. All entrants submitting the correct answers will be entered into a prize draw to win one of 25 USB sticks.

Hints: Each symbol could have multiple valid descriptions. Try using Vicor online calculator to help you IF you are in doubt.