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?
AC Plug Pack (wall wart) plugs - suggestions please
Started by ●September 1, 2020
Reply by ●September 1, 20202020-09-01
On 2/09/2020 12:01 pm, 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?im pretty sure there are no good options, but I,m just checking
Reply by ●September 1, 20202020-09-01
On 9/1/2020 7:01 PM, 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?So, your "wall wart" delivers AC? Can you put a bridge just inboard of the connector and cover the DC +, DC -, and AC cases? [You're still at the mercy of wrong voltage rating...]
Reply by ●September 1, 20202020-09-01
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. 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. Try to make the item damage proof if used with a DC pak up to 12V. ..... Phil
Reply by ●September 2, 20202020-09-02
On Tuesday, September 1, 2020 at 7:01:50 PM UTC-7, 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 plug... > Time marches on plug packs get mixed in together and "hey this fits" and > pzzzt... magic smoke happens to someones piece of kit.First suggestion: make sure the inlet port is clearly labeled, both polarity and voltage, DC or otherwise. Hope for curious folk to find the specification, and test for fit of the mechanical bits. Less interesting: if you use an AC pack, in-the-device bridge or voltage-doubler rectification, then follow up with a switchmode supply, you can't get the wrong polarity, and maybe can tolerate the highest of the safe-low-voltage input possibilities. I've done this with 36-70VDC telecom power modules, it works (within limits, at a cost).
Reply by ●September 2, 20202020-09-02
On 2020-09-02, whit3rd <whit3rd@gmail.com> wrote:> On Tuesday, September 1, 2020 at 7:01:50 PM UTC-7, 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 plug... >> Time marches on plug packs get mixed in together and "hey this fits" and >> pzzzt... magic smoke happens to someones piece of kit. > > First suggestion: make sure the inlet port is clearly labeled, both polarity > and voltage, DC or otherwise. Hope for curious folk to find the > specification, and test for fit of the mechanical bits. > > Less interesting: if you use an AC pack, in-the-device bridge or voltage-doubler > rectification, then follow up with a switchmode supply, you can't get > the wrong polarity, and maybe can tolerate the highest of the safe-low-voltage > input possibilities. I've done this with 36-70VDC telecom power modules, it works > (within limits, at a cost).I once spent 20 minutes on the phone to customer support for a device (a very important IEEE 802.3 to IEEE 1284 converter needed for payroll) because the power pack had gone missing, just while they were telling me that I had to have their genuide power pack, the screwless case came open in my hands to reveal a bridge rectifier, 100uF cap and an LM7805. I soon found a suitable power pack. -- Jasen.
Reply by ●September 2, 20202020-09-02
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. NT
Reply by ●September 2, 20202020-09-02
On 02/09/2020 03:01, 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?Use two connectors, one for each pole. -- Cheers Clive
Reply by ●September 2, 20202020-09-02
On 2020-09-01 22:18, david eather wrote:> On 2/09/2020 12:01 pm, 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? > > im pretty sure there are no good options, but I,m just checkingThe only vaguely common alternatives I've seen are round DIN plugs or 3.5 mm phone plugs. BITD modems ran off 24VAC warts with those same round connectors. A D-sub might work. Alternatively, nearly all the warts I've seen use 2.1 or 2.5 mm centre pins, 5.5 mm outside. Maybe use an odd size, like this one? <https://www.digikey.com/product-detail/en/cui-devices/PPM-2-35135-S1/102-4709-ND/9486620> 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 2, 20202020-09-02
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.> > 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. > > > ..... Phil > > > >
