Bill Sloman <bill.sloman@ieee.org> wrote in news:23103e40-ea55-4d4b-b33c-946330e7c99b@googlegroups.com:> The filtering is between the output of the supply and device it is > powering.Do not need a primer from an utter retard. We were powering a $35k synthesizer by the mfgr specs. Their suggestion to use a linear instead of a switcher has to do with detection of jitter during operation. Incorporating the linear fixed it. Incorporating a filter on the switcher did not, because the EMI flooded the chassis and the jitter got injected despite the rail getting clean filtration. The linear and no post filter fixed it and was cheaper than filtering. It matters at tens of GHz. You are a 100% pure noise jackass.
high voltage charge pump
Started by ●December 30, 2019
Reply by ●January 2, 20202020-01-02
Reply by ●January 2, 20202020-01-02
Bill Sloman <bill.sloman@ieee.org> wrote in news:23103e40-ea55-4d4b-b33c-946330e7c99b@googlegroups.com:> Your original claim was that " We had some very noise sensitive > devices that we were only able to power with linear supplies."Yep. That is what we decided to use. With millions of dollars being invested by the DoD, we do what they tell us to do. We engineer into the system the proven circuits they want used. When on makes a 1024 channel stimulator where all of them are synched to within a nanosecond of each other, one wants repeatability and cost effectiveness and precision. Doing that across 16 racks of gear takes real engineering, not some dork spouting off basic, fully understood bullshit about how to filter a supply rail.> You had enough control over what you used to reject switching > power supplies.Design choices were 100% our engineering group's scope. Us and the DoD. You are an unintelligent asshole, at best.> If you'd had a better grasp of what you were doingThe presumptuous pussy, Billy Sloman cannot go a single post without insulting folks and he can't even get that right.> you could have rejected the noisier switching power supplies.We rejected switchers altogether for that application, you stupid fuck! You seem to have a problem with that choice. Sorry, PUTZ, but you are the idiot. Bill Sloman, being a Doanld J. Trumplike utter retard yet agin.
Reply by ●January 2, 20202020-01-02
On Thu, 2 Jan 2020 02:20:06 -0800 (PST), Klaus Kragelund <klauskvik@hotmail.com> wrote:>On Thursday, January 2, 2020 at 2:45:47 AM UTC+1, jla...@highlandsniptechnology.com wrote: >> On Wed, 1 Jan 2020 16:45:53 -0800 (PST), Klaus Kragelund >> <klauskvik@hotmail.com> wrote: >> >> >On Thursday, January 2, 2020 at 12:39:54 AM UTC+1, jla...@highlandsniptechnology.com wrote: >> >> On Wed, 1 Jan 2020 15:13:25 -0800 (PST), Klaus Kragelund >> >> <klauskvik@hotmail.com> wrote: >> >> >> >> >On Wednesday, January 1, 2020 at 5:18:56 PM UTC+1, jla...@highlandsniptechnology.com wrote: >> >> >> On 1 Jan 2020 05:34:23 -0800, Winfield Hill <winfieldhill@yahoo.com> >> >> >> wrote: >> >> >> >> >> >> >Bill Sloman wrote... >> >> >> >> >> >> >> >> On January 1, 2020, jlarkin wrote: >> >> >> >>> >> >> >> >>> We don't use power transformers much these days. We usually >> >> >> >>> buy fully standards-compliant, universal-input switching >> >> >> >>> power supplies, wall-warts or enclosed boxes. >> >> >> >> >> >> >> >> Which is fine until you need a power rail which isn't >> >> >> >> available off the shelf. >> >> >> > >> >> >> > A simple solution to that problem is to add a fixed-ratio >> >> >> > bus converter, see AoE x-Chapter 9x.16, "DC transformer". >> >> >> >> >> >> Big switching supplies, for serious power busses, are available in >> >> >> most any voltage, and are available as adjustable. >> >> >> >> >> > >> >> >True >> >> > >> >> >At our firm, we never use standard supplies. Price is king, so we need to find lowest cost. Even at low volumes, it pays to do a custom design >> >> > >> >> > >> >> >> I usually build a lot of secondary linear and switching regs, on my PC >> >> >> boards, that never get near the AC line, so I can generally design >> >> >> around a 24 volt wart or equivalent. We buy supplies with all the >> >> >> conformance stickers, real or maybe not, and that work anywhere in the >> >> >> world without tap switching and fuse changing hazards. >> >> >> >> >> >> It's a lot easier to do a CE compliance doc if the power supply is >> >> >> already conforming. >> >> >> >> >> > >> >> >Only true if your power requirement is below 15W. If your unit draws more, or the external supply you use can supply more >> >> > >> >> >Above 15W all the rules with fire comes into play, so the approval process is pretty much the same as approving your own custom supply. And the cost for the approval is not that high, complete product might be 15k USD for an advanced product with several insulation systems >> >> > >> >> >The hurdle with insulation systems is that it seems UL by amazing coincidence have an idea to only approve components/parts that is not part of the IEC system, so that one is forced to make both US and EU variants >> >> > >> >> >> A MeanWell 800 watt switcher box is a fraction of the weight and cost >> >> >> of an 800 watt transformer, and outputs clean DC. The heavy ugly >> >> >> transformer is just the start of a power supply. >> >> >> >> >> >Meanwell is expensive. But an easy solution. When you disassembly the Meanwell and competitor supplies, you find that they really are not that good. We did an internal products, just me and another guy, and in 12 months we had a solution that outprformed the Meanwell types in price and performance. >> >> > >> >> >Cheers >> >> > >> >> >Klaus >> >> >> >> >> >> We have had excellent performance from MeanWell supplies. We've used >> >> about 700 so far. >> >> >> > >> >Our lowest volume products are normaly 10k units >> > >> >Max volume 6 million >> > >> >> Can you make your own for this price? What did 24 man-months of >> >> engineering cost? >> >> >> > >> >We can make it for 10 times lower that price, with efficiency orders of magnitude better (sub 90% efficiency is a joke, cannot see why do would sell such bad products) >> >> 0.1 * $71 is $7.10. But without shipping, and in quantity, you'll have >> to come in around $6 maybe. I sorta doubt that is possible. >> >I have the luxury of having a a lot of high volume parts running in current products (many more than 20 mill pcs per year), so I can cherry pick the low cost ones and use in this supply > >For the custom part, you can do tricks on the pricing of the common mode inductors and transformers that will shock you. Those 2 parts are the most expensive parts in the construction. But it means you have to divert away from your COTS magnetics, and you do not seem to like that. You should reconsider, the price is a different ballgame when you go into deep dialogue with the manufactor > >Also you can do tricks that can remove certain parts that one would normally use, but I cannot disclose those details here for IP reasons > >> How can an efficiency be an order of magnitude above 90%? 900% ? >> > >When you are talking about magnitudes in efficiency and your are above 95%, any 1% increase is really a monumental effort and takes real creative engineering > > >Cheers > >KlausIf you can make a 600 watt offline PFC switcher, in a metal box, for $6, why aren't you selling them on Digikey? -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●January 2, 20202020-01-02
On Wed, 1 Jan 2020 17:21:41 -0800 (PST), Klaus Kragelund <klauskvik@hotmail.com> wrote:>On Thursday, January 2, 2020 at 12:39:54 AM UTC+1, jla...@highlandsniptechnology.com wrote: >> On Wed, 1 Jan 2020 15:13:25 -0800 (PST), Klaus Kragelund >> <klauskvik@hotmail.com> wrote: >> >> >On Wednesday, January 1, 2020 at 5:18:56 PM UTC+1, jla...@highlandsniptechnology.com wrote: >> >> On 1 Jan 2020 05:34:23 -0800, Winfield Hill <winfieldhill@yahoo.com> >> >> wrote: >> >> >> >> >Bill Sloman wrote... >> >> >> >> >> >> On January 1, 2020, jlarkin wrote: >> >> >>> >> >> >>> We don't use power transformers much these days. We usually >> >> >>> buy fully standards-compliant, universal-input switching >> >> >>> power supplies, wall-warts or enclosed boxes. >> >> >> >> >> >> Which is fine until you need a power rail which isn't >> >> >> available off the shelf. >> >> > >> >> > A simple solution to that problem is to add a fixed-ratio >> >> > bus converter, see AoE x-Chapter 9x.16, "DC transformer". >> >> >> >> Big switching supplies, for serious power busses, are available in >> >> most any voltage, and are available as adjustable. >> >> >> > >> >True >> > >> >At our firm, we never use standard supplies. Price is king, so we need to find lowest cost. Even at low volumes, it pays to do a custom design >> > >> > >> >> I usually build a lot of secondary linear and switching regs, on my PC >> >> boards, that never get near the AC line, so I can generally design >> >> around a 24 volt wart or equivalent. We buy supplies with all the >> >> conformance stickers, real or maybe not, and that work anywhere in the >> >> world without tap switching and fuse changing hazards. >> >> >> >> It's a lot easier to do a CE compliance doc if the power supply is >> >> already conforming. >> >> >> > >> >Only true if your power requirement is below 15W. If your unit draws more, or the external supply you use can supply more >> > >> >Above 15W all the rules with fire comes into play, so the approval process is pretty much the same as approving your own custom supply. And the cost for the approval is not that high, complete product might be 15k USD for an advanced product with several insulation systems >> > >> >The hurdle with insulation systems is that it seems UL by amazing coincidence have an idea to only approve components/parts that is not part of the IEC system, so that one is forced to make both US and EU variants >> > >> >> A MeanWell 800 watt switcher box is a fraction of the weight and cost >> >> of an 800 watt transformer, and outputs clean DC. The heavy ugly >> >> transformer is just the start of a power supply. >> >> >> >Meanwell is expensive. But an easy solution. When you disassembly the Meanwell and competitor supplies, you find that they really are not that good. We did an internal products, just me and another guy, and in 12 months we had a solution that outprformed the Meanwell types in price and performance. >> > >> >Cheers >> > >> >Klaus >> >> >> We have had excellent performance from MeanWell supplies. We've used >> about 700 so far. >> >> Can you make your own for this price? What did 24 man-months of >> engineering cost? >> >> https://www.amazon.com/gp/product/B00G8UDEQ8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 >> >> >Sub 90% efficiency does indicate they just settled for a PFC and flyback design, which is a bad move > >Do you have a picture of the PCB so we can what they have chosen ? > >Cheers > >KlausHere's some pics of a similar MeanWell supply. https://www.dropbox.com/sh/29nrzcned50nde5/AADt7PbPBUWt2nYM8hzqe95za?dl=0 It's potted, presumably for heat transfer, since this on is very small and has no fan. I tested it in free still air, but it's meant to be conduction cooled. My degc/w numbers are actually watts/degc. Output regulation was perfect, to four digits. For my product, I'll use a bigger one, 800 watts, which includes a fan. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●January 2, 20202020-01-02
On Wed, 1 Jan 2020 23:38:09 -0500, bitrex <user@example.net> wrote:>On 1/1/20 11:24 PM, jlarkin@highlandsniptechnology.com wrote: >> On Wed, 1 Jan 2020 22:39:43 -0500, bitrex <user@example.net> wrote: >> >>> On 1/1/20 11:18 AM, jlarkin@highlandsniptechnology.com wrote: >>>> On 1 Jan 2020 05:34:23 -0800, Winfield Hill <winfieldhill@yahoo.com> >>>> wrote: >>>> >>>>> Bill Sloman wrote... >>>>>> >>>>>> On January 1, 2020, jlarkin wrote: >>>>>>> >>>>>>> We don't use power transformers much these days. We usually >>>>>>> buy fully standards-compliant, universal-input switching >>>>>>> power supplies, wall-warts or enclosed boxes. >>>>>> >>>>>> Which is fine until you need a power rail which isn't >>>>>> available off the shelf. >>>>> >>>>> A simple solution to that problem is to add a fixed-ratio >>>>> bus converter, see AoE x-Chapter 9x.16, "DC transformer". >>>> >>>> Big switching supplies, for serious power busses, are available in >>>> most any voltage, and are available as adjustable. >>>> >>>> I usually build a lot of secondary linear and switching regs, on my PC >>>> boards, that never get near the AC line, so I can generally design >>>> around a 24 volt wart or equivalent. We buy supplies with all the >>>> conformance stickers, real or maybe not, and that work anywhere in the >>>> world without tap switching and fuse changing hazards. >>>> >>>> It's a lot easier to do a CE compliance doc if the power supply is >>>> already conforming. >>>> >>>> A MeanWell 800 watt switcher box is a fraction of the weight and cost >>>> of an 800 watt transformer, and outputs clean DC. The heavy ugly >>>> transformer is just the start of a power supply. >>>> >>> >>> How do small companies that make e.g. tube guitar amps certify their >>> products at reasonable cost? I don't think many of them are UL listed, >>> too expensive. They don't have much choice but to use an internal >>> off-line linear supply they designed themselves such as it is. >> >> Do many certify their products? In europe and asia, they seem to just >> buy CE stickers in bulk. >> >> Some British friends told me that CE means Can't Enforce. >> >> >> > >I didn't know if there was some level of standards certification between >the CE self-policing and getting a UL certification on the mains-powered >equipment which in addition to the hefty initial fees and re-cert fees >they have to regularly test to destruction some number of your products; >it's an expense that small "boutique" mfgrs probably can't afford when >they're only moving dozens or small-hundreds of units a year that cost >say $2000 per. > >That stuff has not ever been "my department" so far.I designed 5 or 6 NMR gradient amps, sold OEM to Agilent. They paid to have them fully lab certified to UL and CE and everything. None were destroyed, and we had no follow-up inspections of any kind. We had to make a few small tweaks, like wire colors and stuff, but didn't have to re-test. I recently self-certified one of our boxes to CE for a customer who needed it in a system. He never asked to see the cert report, or even the signed certificate of conformance. All he wanted was the sticker. It's not awful to self-certify to CE. You can farm out just the EMI part if you don't have the equipment. The biggest hassle is figuring out which specs apply, and getting those specs. If CE is mandatory, why are the specs so expensive? -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●January 2, 20202020-01-02
On Thu, 2 Jan 2020 02:22:36 -0800 (PST), Klaus Kragelund <klauskvik@hotmail.com> wrote:>On Thursday, January 2, 2020 at 4:39:49 AM UTC+1, bitrex wrote: >> On 1/1/20 11:18 AM, jlarkin@highlandsniptechnology.com wrote: >> > On 1 Jan 2020 05:34:23 -0800, Winfield Hill <winfieldhill@yahoo.com> >> > wrote: >> > >> >> Bill Sloman wrote... >> >>> >> >>> On January 1, 2020, jlarkin wrote: >> >>>> >> >>>> We don't use power transformers much these days. We usually >> >>>> buy fully standards-compliant, universal-input switching >> >>>> power supplies, wall-warts or enclosed boxes. >> >>> >> >>> Which is fine until you need a power rail which isn't >> >>> available off the shelf. >> >> >> >> A simple solution to that problem is to add a fixed-ratio >> >> bus converter, see AoE x-Chapter 9x.16, "DC transformer". >> > >> > Big switching supplies, for serious power busses, are available in >> > most any voltage, and are available as adjustable. >> > >> > I usually build a lot of secondary linear and switching regs, on my PC >> > boards, that never get near the AC line, so I can generally design >> > around a 24 volt wart or equivalent. We buy supplies with all the >> > conformance stickers, real or maybe not, and that work anywhere in the >> > world without tap switching and fuse changing hazards. >> > >> > It's a lot easier to do a CE compliance doc if the power supply is >> > already conforming. >> > >> > A MeanWell 800 watt switcher box is a fraction of the weight and cost >> > of an 800 watt transformer, and outputs clean DC. The heavy ugly >> > transformer is just the start of a power supply. >> > >> >> How do small companies that make e.g. tube guitar amps certify their >> products at reasonable cost? I don't think many of them are UL listed, >> too expensive. They don't have much choice but to use an internal >> off-line linear supply they designed themselves such as it is. > >That is dangerous > >In CE you can ship the product, if you are sure you comply with the regulations > >Trouble is, if they ask for the test results, you must be able to provide them with days of leadtime > >Cheers > >KlausBut does that happen? And what if you ignore the request? -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●January 2, 20202020-01-02
On Thursday, January 2, 2020 at 5:44:39 PM UTC+1, jla...@highlandsniptechnology.com wrote:> On Thu, 2 Jan 2020 02:22:36 -0800 (PST), Klaus Kragelund > <klauskvik@hotmail.com> wrote: > > >On Thursday, January 2, 2020 at 4:39:49 AM UTC+1, bitrex wrote: > >> On 1/1/20 11:18 AM, jlarkin@highlandsniptechnology.com wrote: > >> > On 1 Jan 2020 05:34:23 -0800, Winfield Hill <winfieldhill@yahoo.com> > >> > wrote: > >> > > >> >> Bill Sloman wrote... > >> >>> > >> >>> On January 1, 2020, jlarkin wrote: > >> >>>> > >> >>>> We don't use power transformers much these days. We usually > >> >>>> buy fully standards-compliant, universal-input switching > >> >>>> power supplies, wall-warts or enclosed boxes. > >> >>> > >> >>> Which is fine until you need a power rail which isn't > >> >>> available off the shelf. > >> >> > >> >> A simple solution to that problem is to add a fixed-ratio > >> >> bus converter, see AoE x-Chapter 9x.16, "DC transformer". > >> > > >> > Big switching supplies, for serious power busses, are available in > >> > most any voltage, and are available as adjustable. > >> > > >> > I usually build a lot of secondary linear and switching regs, on my PC > >> > boards, that never get near the AC line, so I can generally design > >> > around a 24 volt wart or equivalent. We buy supplies with all the > >> > conformance stickers, real or maybe not, and that work anywhere in the > >> > world without tap switching and fuse changing hazards. > >> > > >> > It's a lot easier to do a CE compliance doc if the power supply is > >> > already conforming. > >> > > >> > A MeanWell 800 watt switcher box is a fraction of the weight and cost > >> > of an 800 watt transformer, and outputs clean DC. The heavy ugly > >> > transformer is just the start of a power supply. > >> > > >> > >> How do small companies that make e.g. tube guitar amps certify their > >> products at reasonable cost? I don't think many of them are UL listed, > >> too expensive. They don't have much choice but to use an internal > >> off-line linear supply they designed themselves such as it is. > > > >That is dangerous > > > >In CE you can ship the product, if you are sure you comply with the regulations > > > >Trouble is, if they ask for the test results, you must be able to provide them with days of leadtime > > > >Cheers > > > >Klaus > > But does that happen? And what if you ignore the request? >I have only seen it once, in an earlier company I worked for, we were asked to provide the information. Luckily we had it all done, so could just send it out If you can't, I do not know exactly what kind of re-enforcement of the rules they have. I think you can be told to return all units Just did a search: https://www.cemarkingassociation.co.uk/how-is-the-ce-mark-enforced/ Seems there are examples of prosecution of non compliance
Reply by ●January 2, 20202020-01-02
On Thursday, January 2, 2020 at 5:32:08 PM UTC+1, jla...@highlandsniptechnology.com wrote:> On Wed, 1 Jan 2020 17:21:41 -0800 (PST), Klaus Kragelund > <klauskvik@hotmail.com> wrote: > > >On Thursday, January 2, 2020 at 12:39:54 AM UTC+1, jla...@highlandsniptechnology.com wrote: > >> On Wed, 1 Jan 2020 15:13:25 -0800 (PST), Klaus Kragelund > >> <klauskvik@hotmail.com> wrote: > >> > >> >On Wednesday, January 1, 2020 at 5:18:56 PM UTC+1, jla...@highlandsniptechnology.com wrote: > >> >> On 1 Jan 2020 05:34:23 -0800, Winfield Hill <winfieldhill@yahoo.com> > >> >> wrote: > >> >> > >> >> >Bill Sloman wrote... > >> >> >> > >> >> >> On January 1, 2020, jlarkin wrote: > >> >> >>> > >> >> >>> We don't use power transformers much these days. We usually > >> >> >>> buy fully standards-compliant, universal-input switching > >> >> >>> power supplies, wall-warts or enclosed boxes. > >> >> >> > >> >> >> Which is fine until you need a power rail which isn't > >> >> >> available off the shelf. > >> >> > > >> >> > A simple solution to that problem is to add a fixed-ratio > >> >> > bus converter, see AoE x-Chapter 9x.16, "DC transformer". > >> >> > >> >> Big switching supplies, for serious power busses, are available in > >> >> most any voltage, and are available as adjustable. > >> >> > >> > > >> >True > >> > > >> >At our firm, we never use standard supplies. Price is king, so we need to find lowest cost. Even at low volumes, it pays to do a custom design > >> > > >> > > >> >> I usually build a lot of secondary linear and switching regs, on my PC > >> >> boards, that never get near the AC line, so I can generally design > >> >> around a 24 volt wart or equivalent. We buy supplies with all the > >> >> conformance stickers, real or maybe not, and that work anywhere in the > >> >> world without tap switching and fuse changing hazards. > >> >> > >> >> It's a lot easier to do a CE compliance doc if the power supply is > >> >> already conforming. > >> >> > >> > > >> >Only true if your power requirement is below 15W. If your unit draws more, or the external supply you use can supply more > >> > > >> >Above 15W all the rules with fire comes into play, so the approval process is pretty much the same as approving your own custom supply. And the cost for the approval is not that high, complete product might be 15k USD for an advanced product with several insulation systems > >> > > >> >The hurdle with insulation systems is that it seems UL by amazing coincidence have an idea to only approve components/parts that is not part of the IEC system, so that one is forced to make both US and EU variants > >> > > >> >> A MeanWell 800 watt switcher box is a fraction of the weight and cost > >> >> of an 800 watt transformer, and outputs clean DC. The heavy ugly > >> >> transformer is just the start of a power supply. > >> >> > >> >Meanwell is expensive. But an easy solution. When you disassembly the Meanwell and competitor supplies, you find that they really are not that good. We did an internal products, just me and another guy, and in 12 months we had a solution that outprformed the Meanwell types in price and performance. > >> > > >> >Cheers > >> > > >> >Klaus > >> > >> > >> We have had excellent performance from MeanWell supplies. We've used > >> about 700 so far. > >> > >> Can you make your own for this price? What did 24 man-months of > >> engineering cost? > >> > >> https://www.amazon.com/gp/product/B00G8UDEQ8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 > >> > >> > >Sub 90% efficiency does indicate they just settled for a PFC and flyback design, which is a bad move > > > >Do you have a picture of the PCB so we can what they have chosen ? > > > >Cheers > > > >Klaus > > Here's some pics of a similar MeanWell supply. > > https://www.dropbox.com/sh/29nrzcned50nde5/AADt7PbPBUWt2nYM8hzqe95za?dl=0 > > It's potted, presumably for heat transfer, since this on is very small > and has no fan. I tested it in free still air, but it's meant to be > conduction cooled. My degc/w numbers are actually watts/degc. > > Output regulation was perfect, to four digits. >Great, thanks a lot From the datasheet, it has PFC like expected. Not really possible to see what kind of converter it is, but looks like a 2 switch flyback or a push pull from the 2 FETs on the bottom cooling plate Cheers Klaus
Reply by ●January 2, 20202020-01-02
On Thursday, January 2, 2020 at 5:23:05 PM UTC+1, jla...@highlandsniptechnology.com wrote:> On Thu, 2 Jan 2020 02:20:06 -0800 (PST), Klaus Kragelund > <klauskvik@hotmail.com> wrote: > > >On Thursday, January 2, 2020 at 2:45:47 AM UTC+1, jla...@highlandsniptechnology.com wrote: > >> On Wed, 1 Jan 2020 16:45:53 -0800 (PST), Klaus Kragelund > >> <klauskvik@hotmail.com> wrote: > >> > >> >On Thursday, January 2, 2020 at 12:39:54 AM UTC+1, jla...@highlandsniptechnology.com wrote: > >> >> On Wed, 1 Jan 2020 15:13:25 -0800 (PST), Klaus Kragelund > >> >> <klauskvik@hotmail.com> wrote: > >> >> > >> >> >On Wednesday, January 1, 2020 at 5:18:56 PM UTC+1, jla...@highlandsniptechnology.com wrote: > >> >> >> On 1 Jan 2020 05:34:23 -0800, Winfield Hill <winfieldhill@yahoo.com> > >> >> >> wrote: > >> >> >> > >> >> >> >Bill Sloman wrote... > >> >> >> >> > >> >> >> >> On January 1, 2020, jlarkin wrote: > >> >> >> >>> > >> >> >> >>> We don't use power transformers much these days. We usually > >> >> >> >>> buy fully standards-compliant, universal-input switching > >> >> >> >>> power supplies, wall-warts or enclosed boxes. > >> >> >> >> > >> >> >> >> Which is fine until you need a power rail which isn't > >> >> >> >> available off the shelf. > >> >> >> > > >> >> >> > A simple solution to that problem is to add a fixed-ratio > >> >> >> > bus converter, see AoE x-Chapter 9x.16, "DC transformer". > >> >> >> > >> >> >> Big switching supplies, for serious power busses, are available in > >> >> >> most any voltage, and are available as adjustable. > >> >> >> > >> >> > > >> >> >True > >> >> > > >> >> >At our firm, we never use standard supplies. Price is king, so we need to find lowest cost. Even at low volumes, it pays to do a custom design > >> >> > > >> >> > > >> >> >> I usually build a lot of secondary linear and switching regs, on my PC > >> >> >> boards, that never get near the AC line, so I can generally design > >> >> >> around a 24 volt wart or equivalent. We buy supplies with all the > >> >> >> conformance stickers, real or maybe not, and that work anywhere in the > >> >> >> world without tap switching and fuse changing hazards. > >> >> >> > >> >> >> It's a lot easier to do a CE compliance doc if the power supply is > >> >> >> already conforming. > >> >> >> > >> >> > > >> >> >Only true if your power requirement is below 15W. If your unit draws more, or the external supply you use can supply more > >> >> > > >> >> >Above 15W all the rules with fire comes into play, so the approval process is pretty much the same as approving your own custom supply. And the cost for the approval is not that high, complete product might be 15k USD for an advanced product with several insulation systems > >> >> > > >> >> >The hurdle with insulation systems is that it seems UL by amazing coincidence have an idea to only approve components/parts that is not part of the IEC system, so that one is forced to make both US and EU variants > >> >> > > >> >> >> A MeanWell 800 watt switcher box is a fraction of the weight and cost > >> >> >> of an 800 watt transformer, and outputs clean DC. The heavy ugly > >> >> >> transformer is just the start of a power supply. > >> >> >> > >> >> >Meanwell is expensive. But an easy solution. When you disassembly the Meanwell and competitor supplies, you find that they really are not that good. We did an internal products, just me and another guy, and in 12 months we had a solution that outprformed the Meanwell types in price and performance. > >> >> > > >> >> >Cheers > >> >> > > >> >> >Klaus > >> >> > >> >> > >> >> We have had excellent performance from MeanWell supplies. We've used > >> >> about 700 so far. > >> >> > >> > > >> >Our lowest volume products are normaly 10k units > >> > > >> >Max volume 6 million > >> > > >> >> Can you make your own for this price? What did 24 man-months of > >> >> engineering cost? > >> >> > >> > > >> >We can make it for 10 times lower that price, with efficiency orders of magnitude better (sub 90% efficiency is a joke, cannot see why do would sell such bad products) > >> > >> 0.1 * $71 is $7.10. But without shipping, and in quantity, you'll have > >> to come in around $6 maybe. I sorta doubt that is possible. > >> > >I have the luxury of having a a lot of high volume parts running in current products (many more than 20 mill pcs per year), so I can cherry pick the low cost ones and use in this supply > > > >For the custom part, you can do tricks on the pricing of the common mode inductors and transformers that will shock you. Those 2 parts are the most expensive parts in the construction. But it means you have to divert away from your COTS magnetics, and you do not seem to like that. You should reconsider, the price is a different ballgame when you go into deep dialogue with the manufactor > > > >Also you can do tricks that can remove certain parts that one would normally use, but I cannot disclose those details here for IP reasons > > > >> How can an efficiency be an order of magnitude above 90%? 900% ? > >> > > > >When you are talking about magnitudes in efficiency and your are above 95%, any 1% increase is really a monumental effort and takes real creative engineering > > > > > >Cheers > > > >Klaus > > If you can make a 600 watt offline PFC switcher, in a metal box, for > $6, why aren't you selling them on Digikey? >It may be slightly larger than 7 USD, mechanics is hard to get in low volume cheap from the get go I am actually sort of working in that route. I do not have the funds yet to do a design like that, but I am working first on POL supplies. I have something in mind that I think would be sort of a gamechanger, but I do not want to reveal it here in a forum. Can I write you a private mail, for your opinion, since you seem to have used at least some number of different POLs over time? Cheers Klaus
Reply by ●January 2, 20202020-01-02
On Thu, 2 Jan 2020 09:02:44 -0800 (PST), Klaus Kragelund <klauskvik@hotmail.com> wrote:>On Thursday, January 2, 2020 at 5:32:08 PM UTC+1, jla...@highlandsniptechnology.com wrote: >> On Wed, 1 Jan 2020 17:21:41 -0800 (PST), Klaus Kragelund >> <klauskvik@hotmail.com> wrote: >> >> >On Thursday, January 2, 2020 at 12:39:54 AM UTC+1, jla...@highlandsniptechnology.com wrote: >> >> On Wed, 1 Jan 2020 15:13:25 -0800 (PST), Klaus Kragelund >> >> <klauskvik@hotmail.com> wrote: >> >> >> >> >On Wednesday, January 1, 2020 at 5:18:56 PM UTC+1, jla...@highlandsniptechnology.com wrote: >> >> >> On 1 Jan 2020 05:34:23 -0800, Winfield Hill <winfieldhill@yahoo.com> >> >> >> wrote: >> >> >> >> >> >> >Bill Sloman wrote... >> >> >> >> >> >> >> >> On January 1, 2020, jlarkin wrote: >> >> >> >>> >> >> >> >>> We don't use power transformers much these days. We usually >> >> >> >>> buy fully standards-compliant, universal-input switching >> >> >> >>> power supplies, wall-warts or enclosed boxes. >> >> >> >> >> >> >> >> Which is fine until you need a power rail which isn't >> >> >> >> available off the shelf. >> >> >> > >> >> >> > A simple solution to that problem is to add a fixed-ratio >> >> >> > bus converter, see AoE x-Chapter 9x.16, "DC transformer". >> >> >> >> >> >> Big switching supplies, for serious power busses, are available in >> >> >> most any voltage, and are available as adjustable. >> >> >> >> >> > >> >> >True >> >> > >> >> >At our firm, we never use standard supplies. Price is king, so we need to find lowest cost. Even at low volumes, it pays to do a custom design >> >> > >> >> > >> >> >> I usually build a lot of secondary linear and switching regs, on my PC >> >> >> boards, that never get near the AC line, so I can generally design >> >> >> around a 24 volt wart or equivalent. We buy supplies with all the >> >> >> conformance stickers, real or maybe not, and that work anywhere in the >> >> >> world without tap switching and fuse changing hazards. >> >> >> >> >> >> It's a lot easier to do a CE compliance doc if the power supply is >> >> >> already conforming. >> >> >> >> >> > >> >> >Only true if your power requirement is below 15W. If your unit draws more, or the external supply you use can supply more >> >> > >> >> >Above 15W all the rules with fire comes into play, so the approval process is pretty much the same as approving your own custom supply. And the cost for the approval is not that high, complete product might be 15k USD for an advanced product with several insulation systems >> >> > >> >> >The hurdle with insulation systems is that it seems UL by amazing coincidence have an idea to only approve components/parts that is not part of the IEC system, so that one is forced to make both US and EU variants >> >> > >> >> >> A MeanWell 800 watt switcher box is a fraction of the weight and cost >> >> >> of an 800 watt transformer, and outputs clean DC. The heavy ugly >> >> >> transformer is just the start of a power supply. >> >> >> >> >> >Meanwell is expensive. But an easy solution. When you disassembly the Meanwell and competitor supplies, you find that they really are not that good. We did an internal products, just me and another guy, and in 12 months we had a solution that outprformed the Meanwell types in price and performance. >> >> > >> >> >Cheers >> >> > >> >> >Klaus >> >> >> >> >> >> We have had excellent performance from MeanWell supplies. We've used >> >> about 700 so far. >> >> >> >> Can you make your own for this price? What did 24 man-months of >> >> engineering cost? >> >> >> >> https://www.amazon.com/gp/product/B00G8UDEQ8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 >> >> >> >> >> >Sub 90% efficiency does indicate they just settled for a PFC and flyback design, which is a bad move >> > >> >Do you have a picture of the PCB so we can what they have chosen ? >> > >> >Cheers >> > >> >Klaus >> >> Here's some pics of a similar MeanWell supply. >> >> https://www.dropbox.com/sh/29nrzcned50nde5/AADt7PbPBUWt2nYM8hzqe95za?dl=0 >> >> It's potted, presumably for heat transfer, since this on is very small >> and has no fan. I tested it in free still air, but it's meant to be >> conduction cooled. My degc/w numbers are actually watts/degc. >> >> Output regulation was perfect, to four digits. >> >Great, thanks a lot > >From the datasheet, it has PFC like expected. Not really possible to see what kind of converter it is, but looks like a 2 switch flyback or a push pull from the 2 FETs on the bottom cooling plate > >Cheers > >KlausI'll take some pics of the bigger unit, which has a fan and isn't potted. Really, these MeanWells are good. I want to get reliable products done, emphasis on DONE, so we don't want to design and certify a power supply that we can buy, all boxed and tested, for $100 or so. Smaller stuff, like dc/dc bricks, we usually buy for a few dollars. CUI, Recom, Murata all make good stuff, but I test a couple to be sure. -- John Larkin Highland Technology, Inc lunatic fringe electronics
