Yes.
The transistors collector requires a constant 600 MilliAmps of DC current, or 15 Amps of DC current.
Computers, and transistors, all use Direct Current.
The Power Supply (SMPS for today's computers), converts AC electricity into low DC voltages for the computer.
The transistor example that uses 600 MilliAmps is a small one.
The one using 15 Amps, (Amperes) sounds like a MOSFET.
More specifically a Power MOSFET,
Power MOSFET - Wikipedia, the free encyclopedia
You may find these two websites will help increase your knowledge.
One based on simple info, the other more to what you are studying now,
1)
HowStuffWorks "Computer"
2)
Uncomplicating the Complicated | Hardware Secrets
More specifically for Number 2 above,
CPU | Hardware Secrets
How a CPU Works | Hardware Secrets
In my opinion, the thinking is to compare how a Central Processing Unit works, and use your new found transistor info to compare, and apply.
Regards,
joecoolvette