the thin oxides at the surface served as insulation albeit no a perfect one, just use them...
goss irons can run at higher flux densities with lower losses than say a noss...
i use the M18 grades 0.35 for power traffos and M6/Z11 0.35mm thick laminations for output transformers..
yes as much as possible, except in cases of high voltages, where creepage distance is observed....
0.5mm thick will also do for power transformers, you need to run them lower flux densities though...
for a 2A3, filament power is 2.5vac x 2 amps or 10 watts total..
two 5842 is 6.3vac x 0.3 amps or 4 watts
5ar4 is 5vac x 2amps or 10 watts,
so for filaments alone you need 24 watts
for plate psu supply 300 vdc at 100ma or 30 watts..
so that is 54 watts in all
the primary of your power traffo needs 54/0.6 or 90 volt amperes
this is minimum, nothing stops you from using bigger..
Thanks Mr Tony.
Very kind of you, I will continue reading this educational topic of transformers.
Very kind of you, I will continue reading this educational topic of transformers.
rm18 is a grade of steel, lower than an m6/z11 but superrior to M58/H50...also it is 0.35mm thick, very good to use for pwoer trafos...and even output trafo...
Hi amigos,
Technical question for experts :
What is the risk to use a SMPS PSU LLC with centre-tap 28-0-28 VDC (dual rail) instead of using a Toroidal 20-0-20 AC power supply with a A3 board that already includes a rectifier ?
Theorically : 28VDC = 20VAC
I guess I should only notice Diode loss ?
Module board :
ZEROZONE assembleld Ver 2.0 passe A3 classe A Mono amplificateur carte 30W Amp bricolage (pas de dissipateur thermique) | AliExpress
Technical question for experts :
What is the risk to use a SMPS PSU LLC with centre-tap 28-0-28 VDC (dual rail) instead of using a Toroidal 20-0-20 AC power supply with a A3 board that already includes a rectifier ?
Theorically : 28VDC = 20VAC
I guess I should only notice Diode loss ?
Module board :
ZEROZONE assembleld Ver 2.0 passe A3 classe A Mono amplificateur carte 30W Amp bricolage (pas de dissipateur thermique) | AliExpress
If there's really a rectifier, I'd short it's diodes by applying wire bridges appropriately.
Best regards!
Best regards!
Thanks but my question is more general : I don't want to modifiy the module, so what is the risk to apply a 30-0-30 VDC to a 20-0-20 AVC on that module with an integrated rectifier ?
Just want to know if it is going to work ? )
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the A3 required +-25 split rails....
two 25volt smps stacked in series, that is what i will use...
two 25volt smps stacked in series, that is what i will use...
As per spec below, recommended Toroidal PSU is 20-0-20 VAC x 2
So thought that 28 VDC SMPS 500W (dual rail) should be OK.
20V AC x 1.4 = 28 V DC
ZEROZONE assembleld Ver 2.0 passe A3 classe A Mono amplificateur carte 30W Amp bricolage (pas de dissipateur thermique) | AliExpress
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your amp shows too many filter caps, so then i doubt that smps is what you need..
looks like toroid traffo is all you need.....
looks like toroid traffo is all you need.....
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I know that amigo ) But my question is not what I need but what I risk : In other words : Will the rectifier allow DC current to pass without causing damage to the module? I guess the diode bridge will set the polarity automatically from power inputs ?
sorry for very late reply, but i think you will need a soft starting circuit for this module...
I figured it out ) You can use both SMPS or Linear PSU with it. If you go for the SMPS you need a dual rail one with the correct current. You will have a Diode loss but it works the same 🙂
Wow, those are monster C cores! What power capability would your estimate at 50Hz grids?
Best regards!
Best regards!