F4 power amplifier

[nonoise]

The 35A will probably be the If rating of the bridge, the slow blow fuse is on the primary of the transformer were the current is much lower than on the secondary the maximum the bridge will see is a function of the output impedance of the secondary winding of the transformer and the // combination of the power supply CRC section and the actual load
(amplifier).

In other words much higher than 2.5 A

[luvdunhill]

Originally posted by nonoise
The 35A will probably be the If rating of the bridge, the slow blow fuse is on the primary of the transformer were the current is much lower than on the secondary the maximum the bridge will see is a function of the output impedance of the secondary winding of the transformer and the // combination of the power supply CRC section and the actual load
(amplifier).

In other words much higher than 2.5 A

I see, this makes perfect sense. Thank you!

I guess all I need is the working voltage for the 220uF capacitors. Does anyone know what the minimum would be here?

[Jaac]

Originally posted by cHoc


You could try http://www.clofis.nl/ and order some of their Seifert heatsinks.

Looks like some sk56 from fischer elektronik or the kl-146-200 from Seifert. Got both of them. The Fischer ones are better finished. See my photo album for the pics

[DocLorren]

Thanks guys for the links to shops for big heatsinks in Europe.
Jaac: pretty impressive chassis you are building there! Mighty tranformer lying left to the heatsink. Your heatsinks will stand up to the task of converting all that current to heat you think?

[Jaac]

Originally posted by DocLorren
Thanks guys for the links to shops for big heatsinks in Europe.
Jaac: pretty impressive chassis you are building there! Mighty tranformer lying left to the heatsink. Your heatsinks will stand up to the task of converting all that current to heat you think?

The amp that you see on the photo's is the finished aleph 5 and having 40 volt dc rails drawing 2 amps thats 160 watts in idle to dissipate by the heat sinks. They get hot, not hotter then a X150.5. tomorrow i will measure the temp of my heat sinks and also of a pair of XA100 to compare with. For the F4 i think the sinks will do the job but i also have some other sinks here at my house and they are bigger and they need some cutting i think to use them for an amp.

[jleaman]

Originally posted by Jaac



The amp that you see on the photo's is the finished aleph 5 and having 40 volt dc rails drawing 2 amps thats 160 watts in idle to dissipate by the heat sinks. They get hot, not hotter then a X150.5. tomorrow i will measure the temp of my heat sinks and also of a pair of XA100 to compare with. For the F4 i think the sinks will do the job but i also have some other sinks here at my house and they are bigger and they need some cutting i think to use them for an amp.

I think you can build a nice x1000 with that piece

Jase

[luvdunhill]

Originally posted by luvdunhill
I guess all I need is the working voltage for the 220uF capacitors. Does anyone know what the minimum would be here? [/B]

hm, 25 V DC maybe?

[Studley]

Nelson

I've ordered a pair of the Plitron 300VA 18v trafos through the group buy. These have the"type 7" primaries which are suitable for 115v or 230v. I'm in the UK and I've just been advised that our mains is in fact 240v +/- 6%. Plitron tell me that these trafos can handle up to 230 +10%, which means they might be just about be ok for worst case of 240v+6%.

Do you use their type 7 trafos in your commercial offerings that are bound for the UK, or do use their type 5 which are configurable for 240v? (Hoping for some additional comfort from you here!)

thanks
Ian

[Nelson Pass]

I use the 240's, but I don't think you should worry, as Plitron
is very conservative, and besides that, we put a Thermistor
in series with the primary.

[Studley]

Thanks Nelson.