On Thursday, 3 September 2020 23:36:40 UTC+1, Phil Hobbs wrote:> On 2020-09-02 05:44, Tabby wrote: > > On Wednesday, 2 September 2020 03:01:50 UTC+1, david eather wrote: > > > >> I have in mind a project that will use AC Plug Packs. For safety and > >> legal reasons I can't change that, but I am troubled by the low voltage > >> power plugs supplied. They are 2.1mm round plugs just like those on > >> almost any DC plug Pack. > >> > >> Time marches on plug packs get mixed in together and "hey this fits" and > >> pzzzt... magic smoke happens to someones piece of kit. > >> > >> are there suggestions for an alternative plug to use. Doesn't need to be > >> polarized (of course), but something hot plug-able would be nice. > >> > >> Any suggestions? > > > > One simple solution is run the kit at the highest commonish wart voltage, 30 or 32v. And always make your warts output ac so psu polarity doesn't matter. Another is to add overvoltage protection. Another is to have the dc socket insde the appliance case. Another is to put the whole wart inside the appliance with just a mains connector user accessible. etc etc. > > I gather you're retired. ;) > > AFAICT the use of AC warts mostly went out with the 56kbaud modem, and > for good reason. That approach requires gigundo wet Al filter caps and > so on in order to be able to handle 50-60 Hz AC. What a waste. > > Cheers > > Phil HobbsI prefer wartable goods to run on anything - they won't, but getting partway there is a real plus. If you design for ac in it can run off correct PSUs, wrong polarity & old iron lumps. That was really the motivation behind said approach. Cap failure doesn't matter if it runs on a dc wart, lytics normally go high ESR low C. NT
AC Plug Pack (wall wart) plugs - suggestions please
Started by ●September 1, 2020
Reply by ●September 3, 20202020-09-03
Reply by ●September 3, 20202020-09-03
On 2020-09-03 20:29, John Larkin wrote:> On Thu, 3 Sep 2020 18:30:06 -0400, Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> On 2020-09-02 17:44, david eather wrote: >>> On 2/09/2020 12:35 pm, Phil Allison wrote: >>>> david eather wrote: >>>> >>>> ================== >>>>> I have in mind a project that will use AC Plug Packs. For safety and >>>>> legal reasons I can't change that, but I am troubled by the low voltage >>>>> power plugs supplied. They are 2.1mm round plugs just like those on >>>>> almost any DC plug Pack. >>>>> >>>>> Time marches on plug packs get mixed in together and "hey this fits" and >>>>> pzzzt... magic smoke happens to someones piece of kit. >>>>> >>>>> >>>> ** Though possible this rarely happens. >>> >>> Sadly, I confess I have done it. An LED clock that used 5volts got it's >>> own wake up call when I plugged 12 volts into it. I really needed the >>> clock and I liked it too. >> >> That's why we standardized on +24V. AC won't kill our boxes because of >> the unidirectional TVS, series Schottky rectifier, and polyfuse. >> However, as you go lower in voltage, your box will draw more operating >> current, so it'll require that much more fault current to switch the >> polyfuse if somebody plugs in the wrong wart. >> >>>> You need to clearly label your AC pack with the name of the item it >>>> goes with and a warning that it be used with no other. >>> >>> Yep, I was thinking that would be the best I could do. >>> >>> Thanks >>> >>>> >>>> Try to make the item damage proof if used with a DC pak up to 12V. >> >> 24V at least.> > We like 24 because it's unlikely that anybody has a higher voltage > wart around, to plug in by mistake. > > Of course, my new pulse generator ships with a 48v wart! >As the wise man said, "Unbreakable toys are very useful for breaking other toys." ;" Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●September 3, 20202020-09-03
On 2020-09-03 21:43, Tabby wrote:> On Thursday, 3 September 2020 23:36:40 UTC+1, Phil Hobbs wrote: >> On 2020-09-02 05:44, Tabby wrote: >>> On Wednesday, 2 September 2020 03:01:50 UTC+1, david eather >>> wrote: >>> >>>> I have in mind a project that will use AC Plug Packs. For >>>> safety and legal reasons I can't change that, but I am troubled >>>> by the low voltage power plugs supplied. They are 2.1mm round >>>> plugs just like those on almost any DC plug Pack. >>>> >>>> Time marches on plug packs get mixed in together and "hey this >>>> fits" and pzzzt... magic smoke happens to someones piece of >>>> kit. >>>> >>>> are there suggestions for an alternative plug to use. Doesn't >>>> need to be polarized (of course), but something hot plug-able >>>> would be nice. >>>> >>>> Any suggestions? >>> >>> One simple solution is run the kit at the highest commonish wart >>> voltage, 30 or 32v. And always make your warts output ac so psu >>> polarity doesn't matter. Another is to add overvoltage >>> protection. Another is to have the dc socket insde the appliance >>> case. Another is to put the whole wart inside the appliance with >>> just a mains connector user accessible. etc etc. >> >> I gather you're retired. ;) >> >> AFAICT the use of AC warts mostly went out with the 56kbaud modem, >> and for good reason. That approach requires gigundo wet Al filter >> caps and so on in order to be able to handle 50-60 Hz AC. What a >> waste. >> >> Cheers >> >> Phil Hobbs > > I prefer wartable goods to run on anything - they won't, but getting > partway there is a real plus. If you design for ac in it can run off > correct PSUs, wrong polarity & old iron lumps. That was really the > motivation behind said approach. > > Cap failure doesn't matter if it runs on a dc wart, lytics normally > go high ESR low C. > > > NT >As I said, I gather you're retired. ;) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●September 4, 20202020-09-04
On 9/3/2020 5:29 PM, John Larkin wrote:> We like 24 because it's unlikely that anybody has a higher voltage > wart around, to plug in by mistake. > > Of course, my new pulse generator ships with a 48v wart!Midspan injectors and a fair bit of industrial networking kit (e.g., APs) are powered from 48VDC. Not likely found in residences -- but not an assurance for commercial establishments.
Reply by ●September 4, 20202020-09-04
On 4/09/2020 8:36 am, Phil Hobbs wrote:> On 2020-09-02 05:44, Tabby wrote: >> On Wednesday, 2 September 2020 03:01:50 UTC+1, david eather wrote: >> >>> I have in mind a project that will use AC Plug Packs. For safety and >>> legal reasons I can't change that, but I am troubled by the low voltage >>> power plugs supplied. They are 2.1mm round plugs just like those on >>> almost any DC plug Pack. >>> >>> Time marches on plug packs get mixed in together and "hey this fits" and >>> pzzzt... magic smoke happens to someones piece of kit. >>> >>> are there suggestions for an alternative plug to use. Doesn't need to be >>> polarized (of course), but something hot plug-able would be nice. >>> >>> Any suggestions? >> >> One simple solution is run the kit at the highest commonish wart >> voltage, 30 or 32v. And always make your warts output ac so psu >> polarity doesn't matter. Another is to add overvoltage protection. >> Another is to have the dc socket insde the appliance case. Another is >> to put the whole wart inside the appliance with just a mains connector >> user accessible. etc etc. > > I gather you're retired. ;) > > AFAICT the use of AC warts mostly went out with the 56kbaud modem, and > for good reason. That approach requires gigundo wet Al filter caps and > so on in order to be able to handle 50-60 Hz AC. What a waste. > > Cheers > > Phil Hobbs >I'm retired. An AC plug pack is an usable way for someone to build a bit of basic power kit without the need to worry about electrical code compliance with all of those hideous, sometimes hidden and often changing requirements. In dinosaur days it was possible to do a *fully* approved (industry, academic and government approved) tertiary diploma that legally entitled you to fit a plug onto a power cord or work on an unplugged electrical appliance, but you could not legally do so because the controlling bodies would not issue you the required ticket unless you did a full electricians apprenticeship. You were fully qualified to teach the apprentices how to do it at a Technical collage, but if you ever tried to do it yourself..... Such is the stupidity (and closed shop system) that existed in my state at the time. I have no idea what it is now, but at the time it was so stupid, so restrictive and so impossible to work with that just about everyone who could ignored it. No longer an option today when you can be sued for just about anything. Low voltage AC is more friendly to simple construction methods - perf board, strip board, hideous home made PCBs brawn by hand. etc. Easier to find components in small quantities, easier to trouble shoot and debug etc. And no switching noise to unexpectedly stick it's nose in where it is not wanted.
Reply by ●September 4, 20202020-09-04
On 9/4/2020 2:47 AM, david eather wrote:> I'm retired. An AC plug pack is an usable way for someone to build a bit of > basic power kit without the need to worry about electrical code compliance with > all of those hideous, sometimes hidden and often changing requirements. InWall warts, bricks, etc. are a cheap way for manufacturers (here) to "inherit" the agency approvals (from the wall wart vendors) instead of doing their own testing and certification.> Such is the stupidity (and closed shop system) that existed in my state at the > time. I have no idea what it is now, but at the time it was so stupid, so > restrictive and so impossible to work with that just about everyone who could > ignored it. No longer an option today when you can be sued for just about > anything. > > Low voltage AC is more friendly to simple construction methods - perf board, > strip board, hideous home made PCBs brawn by hand. etc. Easier to find > components in small quantities, easier to trouble shoot and debug etc. And no > switching noise to unexpectedly stick it's nose in where it is not wanted.If you're looking for "hobbyist quantities" and not pressed for cost/price, there are many options that you can pursue. For example, electric wheelchairs/scooters/mobility aids use XLR connectors to handle the increased current capacity (it's not uncommon for a charger to deliver 8-10A) as well as making the mating of the connector a bit easier (mechanically keyed, large, visible, etc. so folks living with one -- or more! -- handicap aren't also penalized trying to mate some silly connector that comes in umpteen different combinations of ID & OD & polarity & voltage & ampacity. There are many miniDIN connectors (often flimsy) as well as other heftier circular connectors (some with mechanical fasteners to ensure they stay mated). You can also find molded connectors -- OTS and custom -- that can suit your needs... once you've specified them! :> [I really like connectors that can be mated "blind"... but that sorely limits your selections]
Reply by ●September 4, 20202020-09-04
On Thu, 3 Sep 2020 20:28:34 -0700, Don Y <blockedofcourse@foo.invalid> wrote:>On 9/3/2020 5:29 PM, John Larkin wrote: >> We like 24 because it's unlikely that anybody has a higher voltage >> wart around, to plug in by mistake. >> >> Of course, my new pulse generator ships with a 48v wart! > >Midspan injectors and a fair bit of industrial networking kit (e.g., APs) >are powered from 48VDC. Not likely found in residences -- but not an >assurance for commercial establishments.Well, 48 Vdc is the traditional Telcom voltage, so there is lost of stuff available for that voltage. In the US (and I suspect everywhere), the legal dividing line between low voltage and lines voltage is around 50 Vdc, so this is the highest voltage one can use and not have to follow the National Electrical Code for power line systems. In Japan, this starts at 100 Vac, in the US it's 120 Vac, and everywhere else it's ~240 Vac. The Power over Ethernet voltage is 48 Vdc for this reason. The connector pins et al are limited to two amps, so the highest available voltage was used. Joe Gwinn
Reply by ●September 4, 20202020-09-04
On 9/4/2020 10:22 AM, Joe Gwinn wrote:> On Thu, 3 Sep 2020 20:28:34 -0700, Don Y <blockedofcourse@foo.invalid> > wrote: > >> Midspan injectors and a fair bit of industrial networking kit (e.g., APs) >> are powered from 48VDC. Not likely found in residences -- but not an >> assurance for commercial establishments. > > Well, 48 Vdc is the traditional Telcom voltage, so there is lost of > stuff available for that voltage.I'm not sure how much "wall-wart powered" kit like that exists (?)> In the US (and I suspect everywhere), the legal dividing line between > low voltage and lines voltage is around 50 Vdc, so this is the highest > voltage one can use and not have to follow the National Electrical > Code for power line systems. In Japan, this starts at 100 Vac, in the > US it's 120 Vac, and everywhere else it's ~240 Vac.You still have to follow the NEC when routing low voltage signals; esp network cabling.> The Power over Ethernet voltage is 48 Vdc for this reason. The > connector pins et al are limited to two amps, so the highest available > voltage was used.I think heating in the conductors is the bigger concern (not ampacity of connector). Note that legacy PoE only draws ~350mA. By contrast, a bundle of LONG cables (possibly in a raceway) can dissipate a fair bit of heat in that enclosed volume. (you also risk significant voltage drop "at load" at the PD) PoE+ just makes things worse. And 4PPoE is just insane!! :-/ (Sheesh! Why not power your *TV* over the network? Or, charge your electric vehicle?? :> )
Reply by ●September 4, 20202020-09-04
On 09/04/20 01:29, John Larkin wrote:> On Thu, 3 Sep 2020 18:30:06 -0400, Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> On 2020-09-02 17:44, david eather wrote: >>> On 2/09/2020 12:35 pm, Phil Allison wrote: >>>> david eather wrote: >>>> >>>> ================== >>>>> I have in mind a project that will use AC Plug Packs. For safety and >>>>> legal reasons I can't change that, but I am troubled by the low voltage >>>>> power plugs supplied. They are 2.1mm round plugs just like those on >>>>> almost any DC plug Pack. >>>>> >>>>> Time marches on plug packs get mixed in together and "hey this fits" and >>>>> pzzzt... magic smoke happens to someones piece of kit. >>>>> >>>>> >>>> ** Though possible this rarely happens. >>> >>> Sadly, I confess I have done it. An LED clock that used 5volts got it's >>> own wake up call when I plugged 12 volts into it. I really needed the >>> clock and I liked it too. >> >> That's why we standardized on +24V. AC won't kill our boxes because of >> the unidirectional TVS, series Schottky rectifier, and polyfuse. >> However, as you go lower in voltage, your box will draw more operating >> current, so it'll require that much more fault current to switch the >> polyfuse if somebody plugs in the wrong wart. >> >>>> You need to clearly label your AC pack with the name of the item it >>>> goes with and a warning that it be used with no other. >>> >>> Yep, I was thinking that would be the best I could do. >>> >>> Thanks >>> >>>> >>>> Try to make the item damage proof if used with a DC pak up to 12V. >> >> 24V at least. >> >> Cheers >> >> Phil Hobbs > > We like 24 because it's unlikely that anybody has a higher voltage > wart around, to plug in by mistake. > > Of course, my new pulse generator ships with a 48v wart! >Should be cheap, safe and multisource as well, since power over over ethernet uses a 48 volt rail... Chris
Reply by ●September 4, 20202020-09-04
On Thu, 3 Sep 2020 18:43:48 -0700 (PDT), Tabby <tabbypurr@gmail.com> wrote:>On Thursday, 3 September 2020 23:36:40 UTC+1, Phil Hobbs wrote: >> On 2020-09-02 05:44, Tabby wrote: >> > On Wednesday, 2 September 2020 03:01:50 UTC+1, david eather wrote: >> > >> >> I have in mind a project that will use AC Plug Packs. For safety and >> >> legal reasons I can't change that, but I am troubled by the low voltage >> >> power plugs supplied. They are 2.1mm round plugs just like those on >> >> almost any DC plug Pack. >> >> >> >> Time marches on plug packs get mixed in together and "hey this fits" and >> >> pzzzt... magic smoke happens to someones piece of kit. >> >> >> >> are there suggestions for an alternative plug to use. Doesn't need to be >> >> polarized (of course), but something hot plug-able would be nice. >> >> >> >> Any suggestions? >> > >> > One simple solution is run the kit at the highest commonish wart voltage, 30 or 32v. And always make your warts output ac so psu polarity doesn't matter. Another is to add overvoltage protection. Another is to have the dc socket insde the appliance case. Another is to put the whole wart inside the appliance with just a mains connector user accessible. etc etc. >> >> I gather you're retired. ;) >> >> AFAICT the use of AC warts mostly went out with the 56kbaud modem, and >> for good reason. That approach requires gigundo wet Al filter caps and >> so on in order to be able to handle 50-60 Hz AC. What a waste. >> >> Cheers >> >> Phil Hobbs > >I prefer wartable goods to run on anything - they won't, but getting partway there is a real plus. If you design for ac in it can run off correct PSUs, wrong polarity & old iron lumps. That was really the motivation behind said approach.A transformer has the 120/240 problem. We buy universal-input DC-out warts with the full international plug set. There are some really weird ones.> >Cap failure doesn't matter if it runs on a dc wart, lytics normally go high ESR low C. > > >NTJust put one of these first-thing: https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=srh05
