July 15, 200817 yr Richard is a pretty easy guy to talk to and from what I understand the one who actually builds the trafos. All it would take to find out if it's feasible is to shoot him an email. He replied to mine very quickly (hours, not days) and the trafo was built in under a week - exactly as promised.
July 15, 200817 yr Author I'd be interested, if it was encapsulated / shielded. Digipete, you want to take the lead on this one?
July 15, 200817 yr Ok, I will contact Sumr and see what's available and try to get some pricing. Pete
July 15, 200817 yr Anybody figure out what the power consumption for two boards is? Another idea... would it be advantageous to build a sigma22 PS instead, and bypass whats on the Pearl for a PSU?
July 15, 200817 yr Author Anybody figure out what the power consumption for two boards is? Another idea... would it be advantageous to build a sigma22 PS instead, and bypass whats on the Pearl for a PSU? yes. R2 drops about a quarter of a volt, so around 4.7/0.25 per board.. 50mA with headroom.
July 15, 200817 yr yes. R2 drops about a quarter of a volt, so around 4.7/0.25 per board.. 50mA with headroom. I get 53 ma per board, say 100 ma each including headroom, or 8VA for both, so a trafo of about 30+30 15VA should be plenty. Check my math... Avel 236007 30+30 15VA or equivalent seems good.
July 15, 200817 yr Author I get 53 ma per board, say 100 ma each including headroom, or 8VA for both, so a trafo of about 30+30 15VA should be plenty. Check my math... Avel 236007 30+30 15VA or equivalent seems good. yup, looks good. I usually include 20% for transformer headroom, as not to draw more than 80% of rated current from the transformer, but you're good in this case.
July 15, 200817 yr yup, looks good. I usually include 20% for transformer headroom, as not to draw more than 80% of rated current from the transformer, but you're good in this case. Right, this should be at 50% or below the rated current. Probably hard to find less than 15VA for a 30+30V trafo. I'll check with Sumr.
July 15, 200817 yr If you don't mind a split bobbin, Allied has these: Hammond Manufacturing - 186D56 - Allied Electronics 56Vct, 30VA They also have some 6VA Hammond and Triad.
July 16, 200817 yr Here is the input from Sumr for a custom transformer: Peter, I have designed for low flux density, the result is a larger transformer. The OD: 3" HT: 1.3" Input: 1 prim. 120Vac @ 60 Hz, Ouput: 2sec. x 30Vac @ 0.34 amps. A/ Transformer with a core band wrapped around the OD under final mylar insulation. B/ Transformer encapsulated in toroid box with extra steel banding above and below to minimize stray magnetic field. Picture attached of toroid box used in similar application as yours. Pricing based on order of 10 pcs. A/ silicon band US $ 39.00/each B/ Encapsulated, US $ 50.00/each Please let me know if this is of interest. Thankyou, Richard Primrose
July 16, 200817 yr Author Here is the input from Sumr for a custom transformer: Peter, I have designed for low flux density, the result is a larger transformer. The OD: 3" HT: 1.3" Input: 1 prim. 120Vac @ 60 Hz, Ouput: 2sec. x 30Vac @ 0.34 amps. A/ Transformer with a core band wrapped around the OD under final mylar insulation. B/ Transformer encapsulated in toroid box with extra steel banding above and below to minimize stray magnetic field. Picture attached of toroid box used in similar application as yours. Pricing based on order of 10 pcs. A/ silicon band US $ 39.00/each B/ Encapsulated, US $ 50.00/each Please let me know if this is of interest. Thankyou, Richard Primrose hey, thanks! I wonder what the price is less than 10. I suppose its either those or the Avel donuts I posted above: - Avel Y236107 qty 1 = $22.47 + $11.39 shipping ($33.86 each) qty 5 = $21.35 + $13.55 shipping ($24.06 each) I think half of the interested parties in the parts kit wanted a "budget" version, so perhaps the Avel makes more sense here... also lack of universal input is kinda annoying, but not a deal breaker. Also, the picture attached looks like a PCB mount... Opinions?
July 16, 200817 yr Author Here is the input from Sumr for a custom transformer: Peter, I have designed for low flux density, the result is a larger transformer. The OD: 3" HT: 1.3" Input: 1 prim. 120Vac @ 60 Hz, Ouput: 2sec. x 30Vac @ 0.34 amps. A/ Transformer with a core band wrapped around the OD under final mylar insulation. B/ Transformer encapsulated in toroid box with extra steel banding above and below to minimize stray magnetic field. Picture attached of toroid box used in similar application as yours. Pricing based on order of 10 pcs. A/ silicon band US $ 39.00/each B/ Encapsulated, US $ 50.00/each Please let me know if this is of interest. Thankyou, Richard Primrose hey, thanks! I wonder what the price is less than 10. I suppose its either those or the Avel donuts I posted above: - Avel Y236107 qty 1 = $22.47 + $11.39 shipping ($33.86 each) qty 5 = $21.35 + $13.55 shipping ($24.06 each) I think half of the interested parties in the parts kit wanted a "budget" version, so perhaps the Avel makes more sense here... Opinions?
July 16, 200817 yr I assume less than 10 will be more expensive. I would rather get the cheaper Avel, and build a separate supply box located away from the preamp box. Also, see if Avel 236007 30+30 15VA is available. A bit smaller, but still got plenty of power reserve, and might be even cheaper. Just my two cents.
July 16, 200817 yr Author I assume less than 10 will be more expensive. I would rather get the cheaper Avel, and build a separate supply box located away from the preamp box. Also, see if Avel 236007 30+30 15VA is available. A bit smaller, but still got plenty of power reserve, and might be even cheaper. Just my two cents. Excellent! I just sent them an e-mail.
July 16, 200817 yr Author these look sweet: Low Voltage Transformers - 30v to 200v SNC Transformer 30v @ 0.5 amps (TP) 25-3006 SNC transformer, hermetically sealed. Harris P/N: 472-0643-000.
July 16, 200817 yr Author I wonder if there is a nice PCB to use for the unregulated part of the PS? I plan on using a chassis mount rectifier bridge and then a single cap which will be mounted with a clamp. I'll probably leave out the AC filtering. I contacted an individual who sells Pearl kits asking for a few psu boards, and he didn't reply to me
July 17, 200817 yr Author any recommendations on a nice little case that could fit a single PCB? They are 7"x5"x~3" high. The largest Hammond is oh so close..
July 17, 200817 yr How about a Context Engineering 6016? Split Body Enclosures available from Context Engineering I like these better than the Hammonds.
July 17, 200817 yr Author How about a Context Engineering 6016? Split Body Enclosures available from Context Engineering I like these better than the Hammonds. heh. I just was on their site did you purchase them direct? There was another company back that I found that made cases that look like the little creek headphone amplifiers, and like the Whest phono preamps, but I cannot seem to find them now.. oh well. edit: found 'em: www.nutech-eng.com
July 17, 200817 yr Once you move out of the Hammond-type chassis you'll probably find that prices escalate quickly. Example: Lansing Graybox 8.37" (1/2 rack) x 6" x 3.47" (2RU) - part number B2H06-001A - will run you $68 each. You also might see if you can get a quote from someone like Context Engineering for one of their modular cases. I haven't done that for a long time so I can't even remember if it was reasonable or not. Cases are the curse of every diy'er.
July 17, 200817 yr Author hum a hum a hum... I think I'll be trying something from here: Wolgram Products- Sescom Enclosures prices are right and they look decent to boot!
July 17, 200817 yr IIRC the enclosure that I got last December directly from Context ran ~$45 shipped. That was a 6008 I think.
July 17, 200817 yr IIRC the enclosure that I got last December directly from Context ran ~$45 shipped. That was a 6008 I think. Sounds about right. My last pricing info from them is a year old now and probably not current.
July 17, 200817 yr Author hey, thanks! I wonder what the price is less than 10. I suppose its either those or the Avel donuts I posted above: - Avel Y236107 qty 1 = $22.47 + $11.39 shipping ($33.86 each) qty 5 = $21.35 + $13.55 shipping ($24.06 each) I think half of the interested parties in the parts kit wanted a "budget" version, so perhaps the Avel makes more sense here... Opinions? here are the quotes for the Y236007 5 pcs: $18.48 each + $13-ish shipping ($21 each) I think this is a good enough price point to move on, so I'll send some PMs out to people who expressed interested in a parts kit.
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