Valve Itch phono

[Salas]

It takes much time to arrive in a good useable well tested PCB. I just have it in mind for when able. No certain plans yet.

 

[nicoch58]

feeling the itch

 

[WntrMute2]

I'd be interested in a PCB or kit also.

 

[merlin el mago]

Can be enough tx with secondary 250VAC 40VA?

 

[Salas]

Sure, the draw there is about 12W.

 

[merlin el mago]

Thanks Salas.

 

[merlin el mago]

PSUD2 said not: 294VDC, Q-factor quality shows an average more than 400mA is drawn while hte circuit only draws 35mA

 

[stajo]

Delay PSUD one second

 

[Salas]

There will be a sudden draw at charge up and then it will tapper off as usually.
(I designated a 150-160mA 250V secondary at 10% regulation for a 40VA Tx).

 

[merlin el mago]

Delayed 1 second, still peaks & ringing

 

[merlin el mago]

Peaks can be softened with a RC snubber?

 

[stajo]

My guess is that the filter is designed for being good enough for a later regulator, so buld it like it is and then add filltering if you think you need it.

 

[Salas]

But you "read" the bridge current and the Tx voltage. The charge cycle is what you see. Your final ripple will be shown when reading at C2.

 

[merlin el mago]

I only added a filter above 53kHz with 1 ohm 1W & 3uF to remove HF

 

[stajo]

31,6 mV ripple

 

[merlin el mago]

I'm not worried about ripple because I use SSHV2. As Bass translated to English by DHTRob "designing a PSU with DucanAmps PSUDII" I'm looking for an optimal Q-factor (damping), this mean that the supply is capable of restoring in a clean way the lost energy very quickly.

 

[merlin el mago]

Hey guys I need to understand how to use "for miliseconds" and "delay in seconds"? I ask because everyone use a different scale....

 

[stajo]

Well, I dont see any of those ringings. But that has to do with your secondarys dcr and it will be lower the bigger transformer you have. I guess you have a toroid because they have the lower dcr. What you could do if you think you have a problem is add resistors to your secondarys or lower first cap, to trade from ripple.

If you measure without delay you get the whole startup phase and then you dont have the average behaviour under normal run. Therefore add delay until startup phase is over.

If you want to look at startup phase, then no delay ofc.

Measuring time (for milliseconds) is just like x-axis on a scope. Set it so you see the waves properly.

 

[merlin el mago]

Salas what's the max. ripple allowable for SSHV2?

 

[merlin el mago]

Well, I dont see any of those ringings. But that has to do with your secondarys dcr and it will be lower the bigger transformer you have. I guess you have a toroid because they have the lower dcr. What you could do if you think you have a problem is add resistors to your secondarys or lower first cap, to trade from ripple.

If you measure without delay you get the whole startup phase and then you dont have the average behaviour under normal run. Therefore add delay until startup phase is over.

If you want to look at startup phase, then no delay ofc.

Measuring time (for milliseconds) is just like x-axis on a scope. Set it so you see the waves properly.

Thanks for help stajo, I discovered that if I don't put aby delay in sec, the result don't display how much ripple in numbers.