AC-DC Power Supply Flashcards
What does an AC-DC power supply do?
It converts alternating current (AC) from the mains to direct current (DC) for powering electronic devices.
How does an AC-DC power supply work?
It uses a transformer to adjust voltage, a rectifier to convert AC to DC, a filter to smooth the output, and a regulator to maintain a steady DC voltage.
What are the main types of AC-DC power supplies?
Linear power supplies and switching power supplies.
What is a linear power supply?
A power supply that uses a transformer and linear voltage regulator to produce a stable DC output.
What is a switching power supply?
A power supply that converts AC to DC using a high-frequency switching techniques for improved efficiency.
What is a rectifier?
A component that converts AC to DC, typically using diodes or bridge rectifiers.
What is the role of a filter in a power supply?
To smooth out the rectified DC voltage by reducing ripples, often using capacitors or inductors.
What is a voltage regulator in a power supply?
A circuit that ensures the output voltage remains constant despite input or load variations.
What are the key differences between linear and switching power supplies?
Linear supplies are simpler and quieter but less efficient, while switching supplies are more efficient and compact but generate more noise.
What is the efficiency of a power supply?
The ratio of output power to input power, typically expressed as a percentage.
What is the output ripple of a power supply?
The residual AC voltage superimposed on the DC output, measured in millivolts.
What is a regulated power supply?
A power supply that maintains a constant output voltage regardless of input voltages or load changes.
What is an unregulated power supply?
A power supply where the output voltage varies with changes in input voltage or load.
What is a transformerless power supply?
A compact power supply that uses capacitive or resistive dropper circuits instead of a transformer, suitable for low-power applications.
What is the purpose of a heat sink in a power supply?
To dissipate heat generated by components like voltage regulators or transistors.
What is a power factor in a power supply?
The ratio of real power to apparent power, indicating the efficiency of power usage.
What is the typical input voltage range for an AC-DC power supply?
100V to 240V AC, depending on the design and region.
What is the role of a fuse in a power supply?
To protect the circuit from overcurrent by breaking the connection in case of a fault.
What is a flyback converter?
A type of switching power supply that uses a transformer to provide isolation and voltage conversion.
What is a SMPS (Switch-Mode Power Supply)?
A highly efficient power supply that uses high-frequency switching to convert AC to DC.
What is a multi-output power supply?
A power supply that provides multiple DC output voltages from a single AC input.
What is a ripple current in power supplies?
The AC component of the current flowing through the output, which can affect sensitive electronics.
How do you test a power supply?
Use a multimeter to measure the output voltage and current, and an oscilloscope to check for ripples.
What is a standby power supply?
A power supply that provides a small amount of power to keep a device in standby mode.
What is the role of an EMI filter in a power supply?
To reduce electromagnetic interference generated by the power supply.
What is a power supply’s load regulation?
The ability to maintain a stable output voltage as the load varies.
What is input surge protection in a power supply?
A feature that protects the circuit from voltage spikes or surges on the AC input.
What can go wrong with power supplies?
Overheating, component failure, excessive ripple, or voltage instability.
What is the MTBF (Mean Time Between Failures) of a power supply?
A reliability measure indicating the average operational time before failure.
How do you ensure proper power supply selection?
Match the output voltage, current rating, efficiency, and ripple requirements to the application.
