need help to build my own smps based on blaupunkt schematics gta400 please

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#123
Ok Thanks Perry 🙂

I put 1% resistors because i prefer to have better supply than the original 🙂

I drill all holes on the pcb board and i put some components.

I need to buy 8 capacitors for the primary of the supply and 4 capacitors for the secondary.
All are special audio and are expensive 🙁 but with that the smps works great 🙂
 
#124
There will be no audible difference in the sound quality with expensive or inexpensive components as long as the components are chosen properly.

For the rail capacitors, expensive capacitors may not be any better and capacitors specifically built for this type of circuit may be more reliable. For filter capacitors, you want low ESR/low impedance caps. If the supply will be driven hard and the capacitors will need to be able to survive higher operating temperatures, 105C caps would be more reliable. In virtually all amplifiers, 105C caps are used on the primary side.
 
#125
Hello

Thanks Perry 🙂

So could you tell me please what total value of capacitor i need for the primary side and the rail caps ?

On the schematics of blaupunkt they put 4 caps of 2200µF on the primary side and 2 caps of 3300µF on the rail caps 🙁 for me it's a cheap supply with that.

Because if I compare with a soundstream amplifier reference, they put a lot of low esr caps on the primary side and rail caps. if soundstream do that with the reference 160s, it's for a reason ? i think that reduce the stress of the supply when there is more caps due to the disponibily of the power.

Otherwise could you tell me please how to calculate the output power of this supply ?

Thanks 🙂
 
#126
This is being used for audio which means that the load on it varies greatly. The new power supply may be usable for a 400 watt audio amp but if you tried to draw 400 watts continuously (DC output into a resistor) out of it, it would likely fail quickly. There are lots of variables to consider (too many for this forum, the power supply forum may be able to help, though).

The number of capacitors also depends on a lot of variables. Having more capacitors doesn't necessarily do anything to make the power supply better. The 160S (from what I see uses only 2 capacitors). Amps like the Rockford 600a2 uses only four 330uf capacitors and there is no problem. More isn't always better.
 
#127
Hum...ok I understand Perry

so why rockford recommended to put an outside capacitor on their amp 🙄

If i compare with soundstream or Ground zero or brax we can find big caps in their supply.

Maybe it's enough for this rockford amp but i prefer a little more caps than not enough.....

Otherwise i put a photo of my next smps it's based on the same schematics.
I build it in 3 days....

i hope to finish it tomorrow to proceed test 🙂 "i wait an order of components...🙄"

An externally hosted image should be here but it was not working when we last tested it.
 
#128
They recommend using an external cap because they make money when you buy one of their capacitors. If external caps were required, I'd see a lot of amps with blown internal caps and I don't.

Amp manufacturers often do things that aren't necessary to increase sales. Boasting that you have twice the capacitance of another manufacturer can make uninformed people believe that the amp is better. What if a company like Audiobahn would have 10x the caps of a Rockford amp, would that amp be better than the Rockford?

This is your power supply and you can do whatever you want with it. Having too many caps (especially on the primary side) won't cause a problem. You're doing this to satisfy yourself and no one else.
 
#130
On primary there is really no need for that many, unless you are planning to use really small input wire, not recommended at all. For output, if not regulated it ok also to have more, but if you intend to keep voltage at the same level, less is more in that case, since feedback does the job of keeping voltage the same, not capacitors

Board is ok, I would go in other direction, smaller board and shorter tracks, secondary track is massive compared to primary where a lot more current will go

Also, top right fet will have much more resistance in ground (return) path, that will make drop on those fets diffrent then that of left 2 fets... if core not bigger then you need, it could saturate it, since it won't be symmetrical

Also I hope, that blue caps are not on primary side, and that diode... that diode will not handle the input current, also you will have voltage drop for no good reason (that diode is good input reversal protection, but not good for other reasons)
 
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#134
Hello 🙂

Thanks Luka

I use 80V caps because i only have this in stock, and caps is expensive so i keep 80V for the moment.

The supply work fine, i push the amp to a high level and no problem 🙂
the transformer is a little "hot" , fet are cold, nothing more
the test during 30 minutes 😎
 
#140
ZippyTs said:
Any new updates?
Click to expand...

Hello 🙂

Yes a little update because i need to buy capacitors for replace the others...

I change resistors from the CLC filter "22 ohms 2W" with other resistance "22 ohms 10 W !" because the older resistors comes very hot and now the problem is resolved 🙂 i also have a better square wave on the scope it's a perfect square wave 😎
I also use a 1% tolerance caps for the CLC filter 🙂

I"ll put a picture when receive new caps 🙂
 
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