I recommend to look into a datasheet of a high quality power supply. Usually they have listed and specified all essential things.
This can give you an overview of important parameters.
There is no general answer, because a "power supply" can be anything. A battery, a resistor and a zener, a wall wart, all combinations of AC or DC in and out....from 10mW to 100kW...it's a huge range.
1. The input voltage, including lower and upper limits if it may vary.
2. The output voltage and how stable it has to be.
3. The output current, both short and long term.
4. The optimum topology to achieve 1,2 and 3
5. How much space is available for it.
6. Can it dissipate enough heat within that space to prevent overheating.
7. Other environmental issues, ambient temperature, humidity etc.
8. It's life expectancy - this will to some extent decide the types and ratings of components you use.
9. Is it prone to incoming interference through the input or output wiring.
10. Is any interference it produces low enough not to influence outside circuits.
11. Is efficiency particularly important.
12. How long must it sustain output if the input power ceases.
13. Does it need a backup supply or provision for an external backup switch.
When designing anything the spec is everything. The quicker you can get the spec organised and agreed with your customer then the easier it is to develop your solution. Even just having all your parameters written down is a start. Betwixt's list is a good start but it is only a start and your particular circumstance may and probably will require additional terms.
Those decisions will directly affect lifetime of your power supply. You also need to understand what isolation strength you require between the line side and your output rails. You need to decide what lifetime you require from it as a starting point.
Those decisions will directly affect lifetime of your power supply. You also need to understand what isolation strength you require between the line side and your output rails. You need to decide what lifetime you require from it as a starting point.
UL had specified power supply or PCB safety requirement for Human safety.
Generally voltage isolation from high voltage input to low voltage output, it will take care by isolation transformer and PCB pad spacing, Creapage distance and clearance distance are important when selecting the transformer.
All electric and electronic component should select based based on the current /voltage /power rating
For eg o/p voltage is 12VDC then select capacitor with voltage rating higher than 15VDC
Like that fuse, MOV, TVS are selected based on the ratting