The Other 13E1 SE-OTL

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Ant
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#106 Re: The Other 13E1 SE-OTL

Post by Ant »

Hi Ray, playing devils advocate, why go DC in the first place? I see no benefit from a noise (hum) point of view. The old man got his quiet as a mouse with it all in one box

If it is in regard to having both ac and DC in one umbilical from the psu box then yes i can see it, but why not just have 2 at separate sides of the box to keep them separate.

It seems like an unnecessary complication without context. Although I'm sure there is a reason

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Paul Barker
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#107 Re: The Other 13E1 SE-OTL

Post by Paul Barker »

He wrote earlier he has varying mains voltage at home. So he’d like to keep the power consistent.
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#108 Re: The Other 13E1 SE-OTL

Post by Ant »

Ah fair enough, thought there had to be some reason
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Nick
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#109 Re: The Other 13E1 SE-OTL

Post by Nick »

Ray P wrote: Sat Jun 15, 2019 12:13 pm
There are voltage regulator devices that seem to have the right voltage and current numbers on paper but I'm thinking about heat dissipation/reliability; am I right in thinking that keeping the difference between Vin and Vout is the critical thing regarding heat rather than the how high Vout is, coupled with the loss in the reference voltage of the device?

Ta
If its a simple linear then yes, Current * ( Vin - Vout) is roughly the dissipation in the regulator. But its a different matter if its a switching regulator.
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Ray P
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#110 Re: The Other 13E1 SE-OTL

Post by Ray P »

Ant wrote: Sat Jun 15, 2019 12:55 pm It seems like an unnecessary complication without context. Although I'm sure there is a reason
As Paul said Ant, I've noticed that there are times when simple AC heating exceeds the voltage rating of the filament - I assume that over time this might result in a reduced life for the 13E1s with the transformer I'm using and it's probably cheaper to sort out some DC heating than to buy another pair of them.
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Ray P
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#111 Re: The Other 13E1 SE-OTL

Post by Ray P »

Nick wrote: Sat Jun 15, 2019 4:06 pm If its a simple linear then yes, Current * ( Vin - Vout) is roughly the dissipation in the regulator. But its a different matter if its a switching regulator.
Cheers Nick. I was thinking LT1084 in a very simple voltage regulator circuit (essentially as per datasheet) and aiming for 28.5V raw DC on its input.
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pre65
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#112 Re: The Other 13E1 SE-OTL

Post by pre65 »

I've used these for similar purposes.

https://www.ebay.co.uk/itm/NEW-LT1083-A ... SwpkFY7doB
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Ray P
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#113 Re: The Other 13E1 SE-OTL

Post by Ray P »

Yes, that's the sort of thing I had in mind Phil. What voltage/current did you run it at and was it reliable?
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pre65
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#114 Re: The Other 13E1 SE-OTL

Post by pre65 »

I use one in my 15v PSU for the SEG DAC, and one in my 50W chip amp PSU at approx 25v, not sure about the current.

No problems as yet. :)
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jack
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#115 Re: The Other 13E1 SE-OTL

Post by jack »

Phil,

On the eBay LT1083 board, do the stability caps provided match those specified in the LT datasheet?
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pre65
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#116 Re: The Other 13E1 SE-OTL

Post by pre65 »

jack wrote: Sat Jun 15, 2019 10:53 pm Phil,

On the eBay LT1083 board, do the stability caps provided match those specified in the LT datasheet?
To be honest, I've no idea. :oops:
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#117 Re: The Other 13E1 SE-OTL

Post by jack »

pre65 wrote: Sat Jun 15, 2019 10:59 pm
jack wrote: Sat Jun 15, 2019 10:53 pm Phil,

On the eBay LT1083 board, do the stability caps provided match those specified in the LT datasheet?
To be honest, I've no idea. :oops:
Worth checking. The LT108x series are quite sensitive wrt stability and the datasheet is explicit about the types and values of the required capacitors...
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Ray P
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#118 Re: The Other 13E1 SE-OTL

Post by Ray P »

I guess the thing to do is build one and test run it with a load resistor to see how it goes over a longish period of time.
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Ray P
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#119 Re: The Other 13E1 SE-OTL

Post by Ray P »

I've taking some leave this week so today I almost completed the power supply chassis for the 13E1 build. I say power supply chassis, it's actually just a box containing the varios toroidal transformers. Tomorrow I just need to finish hooking up the switch and LED, check everything and put the lid on it.

Mains voltage seems to have been much more stable recently so for now I've left the 13E1 filaments powered with AC; I'll keep an eye on it and reconsider using DC if it deteriorates again.
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#120 Re: The Other 13E1 SE-OTL

Post by Cressy Snr »

Nice to see the project going again Ray.
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