If above "problem" isn't a problem then i wonder if this is a good psu? Rise time is very long and slow what I can understand. Shoog? If nobody have anything negative to say this is what i'm gonna put together next week.
With 5V4-G i can lower first resistor to 100-150R if i want. 330R is meant for 6x5-gt. With 5v4-gt i get little higher B+, beside this very similar to simulate with. B+ is somewhere between 280-290V if i read this Duncan correctly.
With 5V4-G i can lower first resistor to 100-150R if i want. 330R is meant for 6x5-gt. With 5v4-gt i get little higher B+, beside this very similar to simulate with. B+ is somewhere between 280-290V if i read this Duncan correctly.
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Change the CCS load to a resistive load and it will go away. Calculate the value by dividing the final B+ voltage by the final current in amps (ie 15mA becomes 0.015A).What does this mean really?? Don't know how to get to go away..?
I try to avoid using the CCS setting as it fails to model the real world behaviour of cold tubes warming up. It is also worth remembering that though PSU2 is very useful - it is not sophisticated enough to model the heater warm up behaviour of either real world amplifier loads or valve rectifiers. Many of the error messages generated in the first few seconds of a run are misleading.
Thats exactly the sort of power supply I would design with PSU2, the only comment I would make is that its overkill and I would consider merging some of the RC stages to make it simpler. The first resistor is just fine and will extend rectifier life for been bigger.
At some point you just have to settle on a stable design - build it and listen to it for at least a few weeks before considering making any more modifications. You are continually second guessing your choices based on no actual experience - which is not a good way of getting to an excellent result.
Shoog
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Hi,
Since you're into cap rolling, resistor rolling, tube rolling, transformer rolling (actually that one rolled you) and god knows what else, I'd keep that cap at a 10 cm distance for now..... You're only going to stick a soldering tip in it if it's too close to the socket anyway.
Ciao,
P.S. Just kidding. In theory it would be better to have the last cap as close as possible to the tube.
Since you're into cap rolling, resistor rolling, tube rolling, transformer rolling (actually that one rolled you) and god knows what else, I'd keep that cap at a 10 cm distance for now..... You're only going to stick a soldering tip in it if it's too close to the socket anyway.
Ciao,
P.S. Just kidding. In theory it would be better to have the last cap as close as possible to the tube.
Damn, i have to stop this creative fantasy i have
Ok, i understand. I'm probably little crazy
One thing that i wonder (again) that i can't find any info about;
The first res after rectifier does it have to be 100-330R or is it possible to have like 1K or higher there too if i adjust the others?
Ok, i understand. I'm probably little crazy
One thing that i wonder (again) that i can't find any info about;
The first res after rectifier does it have to be 100-330R or is it possible to have like 1K or higher there too if i adjust the others?
Hi,
"One way to improve the filter circuit is to use two capacitors in combination with a resistor. In this circuit, the first capacitor eliminates a large portion of the ripple voltage. The resistor and second capacitor work as an RC network that eliminates the ripple voltage even further.
The advantages of this circuit are that the resulting DC has a smaller ripple voltage and the capacitors can be smaller. The disadvantage is that the resistor drops the DC output voltage. How much depends on the amount of current drawn by the load.
For example, if you use a 100 Ω resistor and the load draws 100 mA, the resistor will drop 10 V (100 0.1). Thus, to provide a final output of 5 V, the rectifier circuit must supply 15 V because of the 10 V drop introduced by the resistor."
Copied from:
How Power Supplies Filter Rectified Current in Electronic Circuits - For Dummies
In your specific case it's a little more complex since you also use an inductor (L).
Bottom line is that all these elements form RC (and L) filtering networks ( view it as a x-over in a speaker if you like) to reduce the ripple on the power supply.
The link posted is entirely NOT my doing.
Ciao,
"One way to improve the filter circuit is to use two capacitors in combination with a resistor. In this circuit, the first capacitor eliminates a large portion of the ripple voltage. The resistor and second capacitor work as an RC network that eliminates the ripple voltage even further.
The advantages of this circuit are that the resulting DC has a smaller ripple voltage and the capacitors can be smaller. The disadvantage is that the resistor drops the DC output voltage. How much depends on the amount of current drawn by the load.
For example, if you use a 100 Ω resistor and the load draws 100 mA, the resistor will drop 10 V (100 0.1). Thus, to provide a final output of 5 V, the rectifier circuit must supply 15 V because of the 10 V drop introduced by the resistor."
Copied from:
How Power Supplies Filter Rectified Current in Electronic Circuits - For Dummies
In your specific case it's a little more complex since you also use an inductor (L).
Bottom line is that all these elements form RC (and L) filtering networks ( view it as a x-over in a speaker if you like) to reduce the ripple on the power supply.
The link posted is entirely NOT my doing.
Ciao,
Hi,
"One way to improve the filter circuit is to use two capacitors in combination with a resistor. In this circuit, the first capacitor eliminates a large portion of the ripple voltage. The resistor and second capacitor work as an RC network that eliminates the ripple voltage even further.
The advantages of this circuit are that the resulting DC has a smaller ripple voltage and the capacitors can be smaller. The disadvantage is that the resistor drops the DC output voltage. How much depends on the amount of current drawn by the load.
For example, if you use a 100 Ω resistor and the load draws 100 mA, the resistor will drop 10 V (100 0.1). Thus, to provide a final output of 5 V, the rectifier circuit must supply 15 V because of the 10 V drop introduced by the resistor."
Copied from:
How Power Supplies Filter Rectified Current in Electronic Circuits - For Dummies
In your specific case it's a little more complex since you also use an inductor (L).
Bottom line is that all these elements form RC (and L) filtering networks ( view it as a x-over in a speaker if you like) to reduce the ripple on the power supply.
The link posted is entirely NOT my doing.
Ciao,
Ok now i learned something.
What i meant was that is it a rule to use like 100 ohms there to protect rectifier or is it ok to use whatever value.
I was thinking that by that putting less stress on caps?
Hi,
Traditionally resistors were inserted in front of the rectifier (between secondary winding and the rectifier's anode/plate) to protect it from flashing over due too much in rush current.
This was done either by means of the resistance of the power xformer's secondary winding or as described above.
The first cap behind the rectifier has a limited value (depending on the type of rect.) for the same reason.
Provided the caps are of sufficient voltage rating to deal with the peak voltage this is not a problem.
Take care not to create a resonant tank by shuffling values around though. Always sim first in Duncan's PSU Designer.
The otal sum of all R elements combined + the voltage drop of the rectifier will set the final B+ value.
Ciao,
Traditionally resistors were inserted in front of the rectifier (between secondary winding and the rectifier's anode/plate) to protect it from flashing over due too much in rush current.
This was done either by means of the resistance of the power xformer's secondary winding or as described above.
The first cap behind the rectifier has a limited value (depending on the type of rect.) for the same reason.
Provided the caps are of sufficient voltage rating to deal with the peak voltage this is not a problem.
Take care not to create a resonant tank by shuffling values around though. Always sim first in Duncan's PSU Designer.
The otal sum of all R elements combined + the voltage drop of the rectifier will set the final B+ value.
Ciao,
Do you think it's a good idea to insert some 100-330R before rect, on the 300v sec in my case? Like in the "glory" days?
Hi,
That will depend on the rectifier type you be using ( see datasheet) and the DC resistance of the B+ secondary winding.
If the latter is too low then you should make up for the difference with resistors of the appropriate value.
Ciao,
5V4-G = 100ohm
6X5-GT = 330ohm
sec.winding (2x300V) is 127 ohm.
So with 6X5 i have to add some 220R?
And where would it be appropriate to solder these, before or after fuse(s)? I'm thinking right on the socket/pins.
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Hi,
The resistor should be put between the xformer's sec. windings and the anodes of the rectifier.
If these feeds are fused then put the R in front of the fuses.
The value can be less than what you calculated since this does not take the prim. winding's resistance into account.
If I may point you to this excellent overview by The Valve Wizard:
The Valve Wizard
Ciao,
The resistor should be put between the xformer's sec. windings and the anodes of the rectifier.
If these feeds are fused then put the R in front of the fuses.
The value can be less than what you calculated since this does not take the prim. winding's resistance into account.
If I may point you to this excellent overview by The Valve Wizard:
The Valve Wizard
Ciao,
Project going slowly... Solder tin arrived but i need more time
I'm not sure of Watt rating of res in PSU, is 2W enough here? And before rectifier (more ripple) can 5-6W be ok?
Also wonder if 500mA main fuse is ok? And for both "legs" (300V/100-150ohm) to anod on rectifier can i put 200mA? (I don't have any smaller) If the load are about 12mA it should be close to that right /2?
I'm not sure of Watt rating of res in PSU, is 2W enough here? And before rectifier (more ripple) can 5-6W be ok?
Also wonder if 500mA main fuse is ok? And for both "legs" (300V/100-150ohm) to anod on rectifier can i put 200mA? (I don't have any smaller) If the load are about 12mA it should be close to that right /2?
Sounds promising (after 2 hours)...
PT is cold... tubes are not with 250R equal to the two series CREE diodes, about 1.7V... But one tube is glowing little more then the other (see pics) Is that normal?? I saw that before too. Matching were 0,4V between them new but that gap is bigger now.. 1,73V on one and 1.63V on the other.. Have I weared out the tubes already? Isn't 1,73V close to 7mA? Should i keep this and have the triodes "balanced"?
PT is cold... tubes are not with 250R equal to the two series CREE diodes, about 1.7V... But one tube is glowing little more then the other (see pics) Is that normal?? I saw that before too. Matching were 0,4V between them new but that gap is bigger now.. 1,73V on one and 1.63V on the other.. Have I weared out the tubes already? Isn't 1,73V close to 7mA? Should i keep this and have the triodes "balanced"?
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