Advanced Qualification · A-004 Power supplies · A-004-004-002
In any regulated power supply, the output is cleanest and the regulation is best:
- A across the load
- B at the output of the pass transistor
- C at the point where the sampling network or error amplifier is connected
- D across the secondary of the pass transistor
Correct answer: C — at the point where the sampling network or error amplifier is connected. From the official ISED question bank, verified word for word.
Why
The output is cleanest and most stable exactly where the sampling network or error amplifier measures it, because the regulator uses that specific signal to correct any voltage drops or spikes before they reach the rest of the circuit. The full explanation — and one for every question — is in Pro.
Practise this section
Power supplies: rectifiers, filtering, regulation, switching supplies and their failure modes.