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Power supply current?

P

Peter Percival

Guest
I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?
 
R

Ralph Mowery

Guest
In article <r6nhhe$k81$1@news.albasani.net>, peterxpercival@hotmail.com
says...
I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?
It would be helpful if you would list some of the valves numbers and how
many valves you plan on operating at one time. Do not forget that you
need the filiment voltage also. That could be 5, 6.3, 12.6, just to
start with. You may need other voltages, but they are the most common.

The current for one valve could run from 50 to 200 ma.
 
P

Peter Percival

Guest
Ralph Mowery wrote:
In article <r6nhhe$k81$1@news.albasani.net>, peterxpercival@hotmail.com
says...

I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?



It would be helpful if you would list some of the valves numbers and how
Not yet decided! Bog standard AF triodes, probably.

many valves you plan on operating at one time. Do not forget that you
need the filiment voltage also. That could be 5, 6.3, 12.6, just to
start with. You may need other voltages, but they are the most common.

The current for one valve could run from 50 to 200 ma.
Recommendations for suitable PSUs?
 
D

default

Guest
On Thu, 9 Apr 2020 17:47:17 +0100, Peter Percival
<peterxpercival@hotmail.com> wrote:

Ralph Mowery wrote:
In article <r6nhhe$k81$1@news.albasani.net>, peterxpercival@hotmail.com
says...

I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?



It would be helpful if you would list some of the valves numbers and how

Not yet decided! Bog standard AF triodes, probably.
The chosen tube and power level and class of operation would be
helpful. A visit to a "ham fest" or some such might yield a suitable
PS. They call the old stuff - "boat anchors" because they are heavy.

I picked up a 0 - 1,000 Volt at one amp - For $15. I couldn't even
buy the variac for that price. It was built by a master on a 19" rack
panel, with metered output. I took out the ancient diodes put in some
modern ones and put a filament transformer in the space it opened up.
many valves you plan on operating at one time. Do not forget that you
need the filiment voltage also. That could be 5, 6.3, 12.6, just to
start with. You may need other voltages, but they are the most common.

The current for one valve could run from 50 to 200 ma.

Recommendations for suitable PSUs?
 
P

Phil Allison

Guest
Peter Percival wrote:

---------------------
I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?
** If you are not competent to make yourself one - you need to think of another way to waste spare time.

BTW This has all the signs of being a stupid troll.


...... Phil
 
P

Peter Percival

Guest
Phil Allison wrote:
Peter Percival wrote:

---------------------
I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?



** If you are not competent to make yourself one
I'd love to. Please point me in the direction of a circuit diagram.

- you need to think of another way to waste spare time.

BTW This has all the signs of being a stupid troll.


..... Phil
 
D

default

Guest
On Fri, 10 Apr 2020 10:27:14 +0100, Peter Percival
<peterxpercival@hotmail.com> wrote:

Phil Allison wrote:
Peter Percival wrote:

---------------------
I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?



** If you are not competent to make yourself one

I'd love to. Please point me in the direction of a circuit diagram.
I guess you're new to the Internet? They have these things called
"search engines" and all you gotta do is put a few words in, and it
spits out sites that have what you want, links and all!

https://diyaudioprojects.com/Schematics/
- you need to think of another way to waste spare time.

BTW This has all the signs of being a stupid troll.


..... Phil
 
P

Peter Percival

Guest
default wrote:
On Fri, 10 Apr 2020 10:27:14 +0100, Peter Percival
peterxpercival@hotmail.com> wrote:

Phil Allison wrote:
Peter Percival wrote:

---------------------
I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?



** If you are not competent to make yourself one

I'd love to. Please point me in the direction of a circuit diagram.

I guess you're new to the Internet? They have these things called
"search engines" and all you gotta do is put a few words in, and it
spits out sites that have what you want, links and all!

https://diyaudioprojects.com/Schematics/
Your sarcasm is misplaced because there is no circuit diagram for a
variable voltage power supply on that page.
- you need to think of another way to waste spare time.

BTW This has all the signs of being a stupid troll.


..... Phil
 
D

default

Guest
On Fri, 10 Apr 2020 15:31:29 +0100, Peter Percival
<peterxpercival@hotmail.com> wrote:

default wrote:
On Fri, 10 Apr 2020 10:27:14 +0100, Peter Percival
peterxpercival@hotmail.com> wrote:

Phil Allison wrote:
Peter Percival wrote:

---------------------
I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?



** If you are not competent to make yourself one

I'd love to. Please point me in the direction of a circuit diagram.

I guess you're new to the Internet? They have these things called
"search engines" and all you gotta do is put a few words in, and it
spits out sites that have what you want, links and all!

https://diyaudioprojects.com/Schematics/

Your sarcasm is misplaced because there is no circuit diagram for a
variable voltage power supply on that page.
"I wish to buy a power supply delivering up to 500V for experiments
with thermionic valves. What would be a suitable current?" Where in
that statement do you see variable supply?

I wish to buy wings so I can fly, what would be a suitable altitude?

You put a variable transformer on any of those PS and you have a
variable output. Lot's easier than a solid state regulator and
current limit operating at 500 V.

Dude, you are establishing yourself as a troll. Derision is
warranted, sarcasm be damned. You seem to have no clear idea what you
want, and that is pretty much where all designs start - a goal.
Without a goal you are just wasting everyone's time.
- you need to think of another way to waste spare time.

BTW This has all the signs of being a stupid troll.


..... Phil
 
R

RheillyPhoull

Guest
On 10/04/2020 10:31 pm, Peter Percival wrote:
default wrote:
On Fri, 10 Apr 2020 10:27:14 +0100, Peter Percival
peterxpercival@hotmail.com> wrote:

Phil Allison wrote:
Peter Percival wrote:

---------------------
I wish to buy a power supply delivering up to 500V for experiments
with
thermionic valves.  What would be a suitable current?



** If you are not competent to make yourself one

I'd love to.  Please point me in the direction of a circuit diagram.

I guess you're new to the Internet?  They have these things called
"search engines" and all you gotta do is put a few words in, and it
spits out sites that have what you want, links and all!

https://diyaudioprojects.com/Schematics/

Your sarcasm is misplaced because there is no circuit diagram for a
variable voltage power supply on that page.


- you need to think of another way to waste spare time.

BTW This has all the signs of being a stupid troll.


.....   Phil
Go to DIY Audio Projects and click on say "Mini Block Push-Pull EL84
(6BQ5) Valve Amplifiers" and just use the power supply part of the circuit.
 
P

Phil Allison

Guest
Peter Percival wrote:

------------------

I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?



** If you are not competent to make yourself one

I'd love to. Please point me in the direction of a circuit diagram.
** You seem to be assuming something elaborate is needed.

FYI;

Such a DC supply does not need to be voltage regulated nor completely supply hum free.

The basic components required are a 120V/240V supply transformer with a 325V secondary, a bridge rectifier and 100uF, 500V electro.

Voltage variability is achieved with a Variac feeding the DC supply - readily available new or used and has a myriad of other uses.

Plus a source of 6.3V at a couple of amps.


...... Phil






..
 
P

Pimpom

Guest
On 4/9/2020 9:42 PM, Peter Percival wrote:
I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?
As others have pointed out, you need to be more specific.
For example, if all you want to do is run a 12AX7/ECC83 double
triode as a preamp, all you need is 250-300V at a few milliamps,
plus 6.3 or 12.6V for the heater.

If you want to include a power amp, then you'll need a much
beefier power supply.
 
P

Pimpom

Guest
On 4/9/2020 10:17 PM, Peter Percival wrote:
Ralph Mowery wrote:
In article <r6nhhe$k81$1@news.albasani.net>, peterxpercival@hotmail.com
says...

I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?



It would be helpful if you would list some of the valves numbers and how

Not yet decided! Bog standard AF triodes, probably.


I'd love to. Please point me in the direction of a circuit
diagram.
Maybe you'd like to try this. I used it many many moons ago -
https://www.dropbox.com/s/9dl0o7z33jiqhft/Tube%20preamp%20power%20supply.png?dl=0
 
P

Peter Percival

Guest
RheillyPhoull wrote:
On 10/04/2020 10:31 pm, Peter Percival wrote:
default wrote:
On Fri, 10 Apr 2020 10:27:14 +0100, Peter Percival
peterxpercival@hotmail.com> wrote:

Phil Allison wrote:
Peter Percival wrote:

---------------------
I wish to buy a power supply delivering up to 500V for experiments
with
thermionic valves.  What would be a suitable current?



** If you are not competent to make yourself one

I'd love to.  Please point me in the direction of a circuit diagram.

I guess you're new to the Internet?  They have these things called
"search engines" and all you gotta do is put a few words in, and it
spits out sites that have what you want, links and all!

https://diyaudioprojects.com/Schematics/

Your sarcasm is misplaced because there is no circuit diagram for a
variable voltage power supply on that page.


- you need to think of another way to waste spare time.

BTW This has all the signs of being a stupid troll.


.....   Phil



Go to DIY Audio Projects and click on say "Mini Block Push-Pull EL84
(6BQ5) Valve Amplifiers" and just use the power supply part of the circuit.
I need a variable voltage, say 100-500 volts.
 
P

Peter Percival

Guest
Phil Allison wrote:
Peter Percival wrote:

------------------

I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves. What would be a suitable current?



** If you are not competent to make yourself one

I'd love to. Please point me in the direction of a circuit diagram.



** You seem to be assuming something elaborate is needed.

FYI;

Such a DC supply does not need to be voltage regulated nor completely supply hum free.

The basic components required are a 120V/240V supply transformer with a 325V secondary, a bridge rectifier and 100uF, 500V electro.

Voltage variability is achieved with a Variac feeding the DC supply - readily available new or used and has a myriad of other uses.

Plus a source of 6.3V at a couple of amps.


..... Phil
Thank you.
 
P

Peter Percival

Guest
Pimpom wrote:
On 4/9/2020 10:17 PM, Peter Percival wrote:
Ralph Mowery wrote:
In article <r6nhhe$k81$1@news.albasani.net>, peterxpercival@hotmail.com
says...

I wish to buy a power supply delivering up to 500V for experiments with
thermionic valves.  What would be a suitable current?



It would be helpful if you would list some of the valves numbers and how

Not yet decided!  Bog standard AF triodes, probably.


I'd love to.  Please point me in the direction of a circuit
diagram.

Maybe you'd like to try this. I used it many many moons ago -
https://www.dropbox.com/s/9dl0o7z33jiqhft/Tube%20preamp%20power%20supply.png?dl=0
Thank you. I'll feed it from a Variac (I have a Bronson) as Phil
Allison suggested.
 
P

Phil Allison

Guest
Peter Percival wrote:

--------------------------

Pimpom wrote:

Maybe you'd like to try this. I used it many many moons ago -
https://www.dropbox.com/s/9dl0o7z33jiqhft/Tube%20preamp%20power%20supply.png?dl=0
** Using two transformers wired like that is a bad idea and will not do what you asked for. The seconds one will be driven into core saturation.


The better way is two identical, 240V to 50 or 60V trannies with windings in SERIES. So the combination is 100/120 to 480V.

Then a Variac drives the low voltage side to easily get 500VDC with NO saturation of any core.




.... Phil
 
E

ehsjr

Guest
On 4/11/2020 2:12 PM, Peter Percival wrote:
Pimpom wrote:
On 4/9/2020 10:17 PM, Peter Percival wrote:
Ralph Mowery wrote:
In article <r6nhhe$k81$1@news.albasani.net>, peterxpercival@hotmail.com
says...

I wish to buy a power supply delivering up to 500V for experiments
with
thermionic valves.  What would be a suitable current?



It would be helpful if you would list some of the valves numbers and
how

Not yet decided!  Bog standard AF triodes, probably.


 > I'd love to.  Please point me in the direction of a circuit
 > diagram.

Maybe you'd like to try this. I used it many many moons ago -
https://www.dropbox.com/s/9dl0o7z33jiqhft/Tube%20preamp%20power%20supply.png?dl=0

Thank you.  I'll feed it from a Variac (I have a Bronson) as Phil
Allison suggested.
Don't use that circuit - see Phil's reply.
And be aware of the capacitor voltage ratings.
Using 400V filter caps in a 500V supply will
destroy the caps.

Ed
 
P

Pimpom

Guest
On 4/12/2020 12:13 PM, ehsjr wrote:
On 4/11/2020 2:12 PM, Peter Percival wrote:
Pimpom wrote:
On 4/9/2020 10:17 PM, Peter Percival wrote:
Ralph Mowery wrote:
In article <r6nhhe$k81$1@news.albasani.net>, peterxpercival@hotmail.com
says...

I wish to buy a power supply delivering up to 500V for experiments
with
thermionic valves.  What would be a suitable current?



It would be helpful if you would list some of the valves numbers and
how

Not yet decided!  Bog standard AF triodes, probably.


 > I'd love to.  Please point me in the direction of a circuit
 > diagram.

Maybe you'd like to try this. I used it many many moons ago -
https://www.dropbox.com/s/9dl0o7z33jiqhft/Tube%20preamp%20power%20supply.png?dl=0

Thank you.  I'll feed it from a Variac (I have a Bronson) as Phil
Allison suggested.

Don't use that circuit - see Phil's reply.
And be aware of the capacitor voltage ratings.
Using 400V filter caps in a 500V supply will
destroy the caps.

Ed
The circuit is not intended to produce 500VDC which is not needed
for, in the OP's words, "bog standard AF triodes". 500V far
exceeds the maximum plate voltage of common AF triodes.

230:12 -> 12:230 transformation will theoretically output 230V AC
which, after rectification and filtering cannot exceed 325V, less
in practice. This was suggested for the OP to dabble with as a
first step.
 
P

Pimpom

Guest
On 4/12/2020 7:55 AM, Phil Allison wrote:
Peter Percival wrote:

--------------------------

Pimpom wrote:

Maybe you'd like to try this. I used it many many moons ago -
https://www.dropbox.com/s/9dl0o7z33jiqhft/Tube%20preamp%20power%20supply.png?dl=0


** Using two transformers wired like that is a bad idea and will not do what you asked for. The seconds one will be driven into core saturation.
I used that configuration because small 6- and 12-volt
transformers were easily available at local parts shops and, in
fact, I had them in stock at that time. It worked.

How will 12V fed to a 12V winding (or 6V to 6V) saturate the core?

The better way is two identical, 240V to 50 or 60V trannies with windings in SERIES. So the combination is 100/120 to 480V.

Then a Variac drives the low voltage side to easily get 500VDC with NO saturation of any core.
Better still would be a transformer with 350V and 6.3V/12.6V
secondaries. But such trannies are probably hard to get these
days and be quite expensive. Of course, if the OP still wants to
go for a variable 500V supply, that's up to him.

Note to the OP: The two transformers are connected back-to-back.
The low voltage output of the first transformer is fed to the low
voltage winding of the second transformer. That is, what would
normally be the secondary winding of the 2nd transformer is used
as the primary.
 
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