I made prototypes some time ago, here are some pictures of the prototypes in operation. They successfully operate down to 9.5VAC and supply 5A for a pair of 813's
I tried adding a soft start feature, but that didn't work at all, thats why there are some parts not mounted on the proto's.
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This board had a major mistake: i forgot to route the groundplane.
Heres the fixed version.
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Ive nearly finished my last batch of 6.3VAC to 6.3VDC supplies. Therefore I am posting the gerbers for these very convenient PSU modules.
Sorry for the Use of MELF resistors, but there was no other way of building these as compact as they are.
Be aware that the main filter capacitors are 22.5mm snap-in types, not 25mm. And these are quite hard to source. Mouser-nr. 871-B41231A3159M000
Fet: 512-RFP12N10L
Controller: 998-MIC5156YN
Cooler is a SK129-38 available from TME or Reichelt.
I will still build these upon request and a minimum of 4PC.
Sorry for the Use of MELF resistors, but there was no other way of building these as compact as they are.
Be aware that the main filter capacitors are 22.5mm snap-in types, not 25mm. And these are quite hard to source. Mouser-nr. 871-B41231A3159M000
Fet: 512-RFP12N10L
Controller: 998-MIC5156YN
Cooler is a SK129-38 available from TME or Reichelt.
I will still build these upon request and a minimum of 4PC.
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nice! just when i needed it. Any recommended range of values for R1, R5 and R6?
Just happened to know this. "Boards are good for 2.5A provided the winding can deliver that much current as the 2x 15mF 10VDC has quite an ugly current waveform."
Yes, the boards are fine up to 2.5A from a 5-6A 6.3VAC winding, the limiting factor is the heating of the diodes. And the dropout voltage of the used FET (200mOhm Rsdon). I routinely test them up to 1.5A output current which should be sufficient for running a bunch of preamp tubes.
You can also use these boards for 6.3VAC to 5VDC for running something like 300B filaments. Or 7VAC to 7.5VDC for running 7.5V thoriated tungsten filament tubes. They are not current sources, but are quite low noise, a number of customers have hooked MIC5156 based supplies up to spectrum analyzers with good results.
You can also use these boards for 6.3VAC to 5VDC for running something like 300B filaments. Or 7VAC to 7.5VDC for running 7.5V thoriated tungsten filament tubes. They are not current sources, but are quite low noise, a number of customers have hooked MIC5156 based supplies up to spectrum analyzers with good results.
With 7V AC those 10V DC caps won't cut the cake I think. That is too tightly chosen. This was the reason I did not buy one so I remember 🙂
R1: depends on what adjustment current you want, i usually go for 390R there, which gives 1.25/390= 3.2mA of Adj current.
Say you want 200V out, given that your trimmer is 20K it gives 65V of output adjustment range. Say you want the trimmer at half position for the 200V value, that means ((200V-1.25V)/3.2mA)-10K = 52K. The closest convenient value is 47K 2W metal film.
Good catch, I will see which 16VDC caps are available in that form factor.
871-B41231A4159M000 Mouser stock number.
This is a very useful 60x100mm board for building a power supply with the ST L200 regulator.
The benefits of this regulator is that it features an adjustable current limit. So its very useful for expensive tubes.
Beware that this is not a low dropout regulator. You need approx 4.5V over the regulator for it to work.
I have some boards left, and plenty of L200's if anyone wants some.
The benefits of this regulator is that it features an adjustable current limit. So its very useful for expensive tubes.
Beware that this is not a low dropout regulator. You need approx 4.5V over the regulator for it to work.
I have some boards left, and plenty of L200's if anyone wants some.
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@v4lve lover - I ordered a few of your Maida boards and they arrived during the week. I built up one today for use in a preamp and it works perfectly right out of the can.
Many thanks for making them public, really useful thing to have.
Many thanks for making them public, really useful thing to have.
I'm glad you like the boards.
I have finished and tested another little project of mine, this is a HV regulator that follows the classical approach. I made this because i had some stock of old TO-3 high voltage transistors and wanted to build something that uses them. Suggested pass transistor is BU205/208 or BUS11.
BF337 can be hard to source, but you can substitute something like a MPSA42 if you cannot find them.
Specs are: 150-250V out with 40-50V higher B+ in. at a current of approx 50mA.
R8 should not be fitted, unless you want to have the foldback regulator feature.
Attached are the Gerbers as usual, the other zip contains the partslist.
Cooler is a TO-3 "star" cooler. I beleive the part number is FK201. it should be mounted on stand-offs because there is a resistor and a diode on the bottom side of the board.
I have two finished boards remaining from my personal order, PM if interested.
Cheers,
V4LVE
I have finished and tested another little project of mine, this is a HV regulator that follows the classical approach. I made this because i had some stock of old TO-3 high voltage transistors and wanted to build something that uses them. Suggested pass transistor is BU205/208 or BUS11.
BF337 can be hard to source, but you can substitute something like a MPSA42 if you cannot find them.
Specs are: 150-250V out with 40-50V higher B+ in. at a current of approx 50mA.
R8 should not be fitted, unless you want to have the foldback regulator feature.
Attached are the Gerbers as usual, the other zip contains the partslist.
Cooler is a TO-3 "star" cooler. I beleive the part number is FK201. it should be mounted on stand-offs because there is a resistor and a diode on the bottom side of the board.
I have two finished boards remaining from my personal order, PM if interested.
Cheers,
V4LVE
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Thanks @v4lve lover. Used your board in Salas 6v6 pre. I connected + and - to a lifted potential (Morgan Jones Thingy) But I guess I should only connect - of your board to the "lifted" potential.
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I could do another batch if there is enough interest. Current interest is at 3Pc i think i can do a batch of ten at 6pc interest.
Cheers,
V4LVE.
Cheers,
V4LVE.