switching powe supply life time??!!

[Navid T]

Hi friends
I want to use some 12V and 2A ( or about 5A too ) switching power supply to use with some 1W LED to lighting room but i'm not sure in which way the powe supply life will be more:
1- using on-off key befor my power adaptor ( 220V ac goes through key to power supply when i want turn on lamps )
2- using the key after power supply ( 12V dc goes to key )
I mean which way have more damage for supply? alternate on and off or long time on?!!
I hope you understand what i mean:grin:
Regards

 

[crutschow]

Not sure if I understand you, but switching power supplies operate from DC so you would put it at the output of the AC to DC adapter. The nominal lifetime of any properly designed solid-state circuit is very long.

 

[Navid T]

sorry for my bad english, when you turn on and off a lamp much times in short time it cause damage the lamp, i want to understand it about switching power supply, let me ask more simple:
i have a circuit that has a switching power supply, some 1 watt leds and a key, what is better to do for me with key about swithcing power maintenance ? i should use key between 220V ac and power supply or between power supply and leds? why?
thanks

 

[E-design]

Switching inverters can last a long time depending on the quality and built of the design. One example: Enphase Energy makes a 250W solar panel inverter guaranteed for over 20 years operating in an ambient temperature of up to 65°C.

 

[schmitt trigger]

I would turn off before the 220VAC
for two reasons:
1) Any circuit that is connected live, will consume power. Small amounts, but still consumes power.
2) Heat with bias degrades certain components: i.e.: electrolytic caps

 

[kam1787]

For an on/off switch, put before the switching power supply. You need a switch rated for the mains voltage and current.

It sounds like quite a few LEDs (5A).............maybe 220VAC LED light 'bulb's might be a better choice.

 

[Navid T]

Thanks a lot for your helps friens, 220V ac LEDs are more expensive here kam, but if i was in your country it was better choice i think:grin: