Newbie needs some help with PSU please

[A Sanchez]

Hi,

I am building an exact copy of this amp and PSU combination:

http://dogbreath.de/Chipamps/GainCar...nCardCopy.html

and I have two toroidal transformers exactly like this one (see photo for exact specs and cables please):

http://www.flickr.com/photos/1157168...7603119448350/

I want to use both toroids (one per channel) and if possible with the same simple bridge (with no caps, resistors, etc).

I have found impossible to understand all the options and terminology, types, specs, etc regarding transformers, I never thought that bit could be that complex.

If some one could help me I would be very grateful.

Regards

Antonio

[AndrewT]

Hi,
what are the diameters of each of the wires forming the various secondary windings?

[A Sanchez]

Hi Andrew,

Primaries say: 20 AWG 300v

Secondaries White Black White say: 20 AWG 600V

All the other secondaries look like half the thickness (at least the plastic) and say: 22 AWG 300V

Many thanks

Antonio

[AndrewT]

Hi,
20awg is about 0.813mm diam.
At 3.1A/sqmm the rating for the 18-0-18 winding is about 1.6A giving 58VA for this winding.

If the advert for this transformer did not mention the other secondaries or implied that the whole transformer VA rating applied to the 18-0-18 secondary then send it back at their cost.

The current rating for the 22awg wires is based on 0.645mm diam giving an area of 0.33sqmm and continuous current of 1Aac.
you can work out the VA rating of the other windings and check the total matches the claimed VA.

[A Sanchez]

Andrew,

Yes, I think I will re-sell or return these toroids. They are sort of smallish, light and a bit cheap really.

I am starting as DIyer and will mess up with gainclones for a while in order to learn.

I think I will invest in a couple of very good quality transformers (for dual mono) that would work well with my current and future projects without the need to upgrade them. Do you have any recommendation?

Thanks


Antonio

[AndrewT]

Hi,
go to Rapid or Farnell or RS and buy your transformers from them.

Alternatively, learn what you really need from a transformer and check Ebay frequently, there are bargains to be had from both new and second use toroids. But you do need to be patient.

[A Sanchez]

Many thanks Andrew