Building first circuit (PSU help)

[easyrider]

hi everyone,

this is going to be my first curcuit and would like to start electircs by building an amp. anyway I would like to make this amp:

LINK


what I would like to know is how to make the powersuply biger.

I would like to make it about 50 - 60V

now I would like to know if all I would need to do is replace the Toroidal with a bigger 1 like 225VA, 2x50V

or would also need to change the capacitors and diodes


thanks

easyrider

 

[GregGC]

Keep everithing the same. And keep in mind that the max voltage LM3875 can take is 84V. It means no more than +40/-40 DC. And this is the absolute maximum. I'd just repeating the project you show in the LINK. That's good enough for beginning.

 

[theChris]

you would need to do more, you would need to calculate if the amplifer becomes voltage or current limited. likely it will be current limited.

next you must find out if the caps you have will work in the powersupply. this means first checking the voltage rating. if it is barely at, or below the expected output of the power supply, then don't use em.
(1.25 * 1.414 * Vs - 1) this is the equation i would use to determine the theoretical votlage across the cap. the 1.414 is from rectifiers, the -1 is from diodes (0.7 - 1.414 depending on half or full bridge). the 1.25 is a rough estimate including power company deviation and when the powersupply has no load.

the diode bridge could be steped up to a 35A or 40A full wave bridge if minimum diode loss is desired.

 

[Nuuk]

You may find my Gainclone FAQ page useful.

 

[easyrider]

thanks guys,

ive decided just to repeat that project in the link.

lease delete this post mods.

easyrider