/ˈpaʊər səˌplaɪ/
noun … “System that provides electrical energy in usable form.”
Power Supply is an electrical device or system that delivers controlled electrical power to an electronic load. Its primary role is to convert energy from a source—such as mains electricity, a battery, or a generator—into the specific voltage, current, and stability required by electronic circuits. Power supplies are foundational to all electronic systems, from tiny embedded devices to large data centers.
A Power Supply typically performs multiple functions beyond simple energy delivery. These include voltage conversion, current limiting, isolation, noise reduction, and protection against faults such as short circuits or overvoltage. In most electronic devices, the power supply quietly does the hardest work, ensuring everything else behaves predictably.
Key characteristics of Power Supply include:
- Voltage regulation: maintains a stable output voltage under varying load conditions.
- Current capacity: defines how much current can be safely delivered.
- Efficiency: ratio of usable output power to input power.
- Ripple and noise: residual fluctuations in the output signal.
- Protection features: overcurrent, overvoltage, thermal, and short-circuit protection.
Common types of Power Supply include linear power supplies, switching power supplies (SMPS), battery-based supplies, and uninterruptible power supplies (UPS). Switching supplies are dominant in modern electronics due to their high efficiency and compact size, while linear supplies are valued for low noise and simplicity.
Workflow example: AC to regulated DC conversion:
ac_input = wall_outlet()
dc_unregulated = rectifier.convert(ac_input)
dc_smoothed = filter.smooth(dc_unregulated)
dc_output = regulator.stabilize(dc_smoothed)
Here, the power supply converts AC into a stable DC voltage suitable for electronic circuits.
Conceptually, a Power Supply is like a well-trained utility system: it takes raw energy from the grid and delivers exactly what each device needs, cleanly and reliably.
See Rectifier, Voltage Regulator, Diode, Integrated Circuit, DC.