Understanding Power Supply Ratings and Compatibility

[sdusheyko]

Hello

i need a 9VAC 1.3A source but it's hard to come by... is there a way i can use a similar source?

i don't know too much about this sort of thing but from what i understand the power output is more important than the individual current or voltage out... is that right? for example, my source would have to be around 12W output (p=iv=1.3*9=11.7watt.) or does the current and voltage rating actually matter?

could i add a resistor to say a 12vac 1a source to drop the voltage to get what i need?

what about vac verses vdc; does this really matter? if my wall socket output is 3p anyway, isn't that like vdc since it's constant?

i'm confused, any help would be much appreciated!

 

[berkeman]

Hello

i need a 9VAC 1.3A source but it's hard to come by... is there a way i can use a similar source?

i don't know too much about this sort of thing but from what i understand the power output is more important than the individual current or voltage out... is that right? for example, my source would have to be around 12W output (p=iv=1.3*9=11.7watt.) or does the current and voltage rating actually matter?

could i add a resistor to say a 12vac 1a source to drop the voltage to get what i need?

what about vac verses vdc; does this really matter? if my wall socket output is 3p anyway, isn't that like vdc since it's constant?

i'm confused, any help would be much appreciated!

The answers to your questions mostly depend on what the AC power source is feeding. What device are you powering, and what are its input power requirements/specifications?

 

[sdusheyko]

9VAC 1.3A digital guitar effects pedal.

 

[berkeman]

9VAC 1.3A digital guitar effects pedal.

I used Google Images, and it looks to be a pretty common power adapter:

http://www.google.com/images?hl=en&source=hp&q=9VAC+1.3A+adapter&gbv=2&aq=f&aqi=&aql=&oq=

Are they that hard to find?

 

[davenn]

Hello

what about vac verses vdc; does this really matter? if my wall socket output is 3p anyway, isn't that like vdc since it's constant?
i'm confused, any help would be much appreciated!

your 3 pin wall socket socket will be supplying 120VAC or maybe 240VAC depending on which country you live in.
And yes that's very different to DC and it matters greatly. Put any sort of AC voltage into a unit that requires a DC voltage and it will probably have an extremely short life span

If for example you are in the USA with 120VAC and you need 9VAC then you need to buy a transformer to drop from 120V to 9V

Dave