vezilka wrote:
Hello,

I'm trying to build this project. I have one question tho...
I have these options available:
36V-AC(2x18V-AC), 100VA. which is 2.7 Amps
http://www.loging.mk/en/2041/176818/0/S ... nsformator30V-AC (2x15V-AC), 200VA. which is 6.6 Amps
http://www.loging.mk/en/2042/179975/0/S ... nsformatoralso my question is which fuse to use with each transformer.
Hi
If only these two options, you should go for the 200 VA, 6,6 A, even if it's only 2x15 VAC, simply because you want the higher current for the amplifier, instead of higher voltage and less current of 100 VA, 2,7 A.
After rectification you should see around 2x21 VDC ( remember that the max voltage/limitation for the TDA2050 is 2x25 VDC ).
More about transformators, in this tutorial from Tom:
viewtopic.php?p=10032#p10032Fuse for the 2x15 VAC transformator:
It depends ...we will take both a 115 and 230 V area calculation.
Generally you take the VA load ( In this case 200 ) and divide that by the input voltage ( 115 or 230 ). Then multiply that by ( 1,35 )
So 200/115 = 1,73 A or 200/230 = 0,87 A
1,73 * 1.35 = 2,33 A ( = T 2,5 A fuse ) or 0,87 * 1,35 = 1,17 A ( = T 1,25 A fuse )
If not a standard current rating for the fuse, always round up to the next available size. Also, use a SLOW BLOW type fuse ( often marked T ) ...don't use F in this case.