what power transfer to

[vstyn]

I want to build power supply using a 7905, what power transfer do i use?

 

[Leftyretro]

I want to build power supply using a 7905, what power transfer do i use?

If you mean what power transformer to use then a very transformer with a secondary of 8vac at one amp or more would work well, a more common 12vac secondary would work but you just have to make sure to heat sink the 7905 well. The primary voltage would of course have to match the utility voltage used in you area.

Lefty

 

[vstyn]

Where do I get the negative voltage for 7905, the transfer has positive voltage

 

[Leftyretro]

Where do I get the negative voltage for 7905, the transfer has positive voltage

The negative voltage comes from the orientation of the rectifier diodes used to convert the AC voltage from the transformer into DC voltage. You should study some power supply circuits to get a better feel for the components used and their purpose. There are tons of circuit examples on the web.

Lefty

 

[audioguru]

I think he wants to blow up the 7905.