90 Volt SMPS possible?

[ethernet]

Hi,
Is it possible to modify a power socket SMPS power supply to lift the voltage to 90-100 volts? Yes, they have a voltage divider and there may be 6 volts of wriggle room. However these chips usually have over voltage protection and the Mosfet switcher tops out at about 48 volts.  60mA for valve HT would be plenty.
Secondly it would be really good to have a beefy SMPS at 56V to drive  a battery whipper snipper whose batteries cost a packet. Higher voltage SMPS dont seem to be on Baliexpress and the like. A variac and bridge rectfier is not my preferred option as Akiexpress postage shot up to $20 kilo like overnight.

[Terry Bites]

No
Any direct off mains convetrer is just waiting to kill you when you're not paying attention.
Wall chargers are itching to get at you.
You need to design or buy a new converter that will run of 5-6V
You can have any output voltage output you like. [not Farringdon's fatal voltages though]
 I'll mention again this handy resource. www.ti.com/design-resources/design-tools-simulation/webench-power-designer.html#design

Plug in  0.1 A out 90V non-isolated low cost and see what pops out.

Or take a punt. www.ebay.co.uk/itm/134341489529?hash=item1f47607379:g:CKEAAOSwPoJjgKQW&amdata=enc%3AAQAHAAABICL%2F6h48807RSH%2BrUfxeEbv9HwQWXC5iLQtc3qiLOWa75MUSirEC1whKasJPz%2BHfautyTdTtrB03g0bJaQiuYTG4DQnvLD%2BGurEvibjRaZKL453laqd29OnRDsGBKEemCNqXdsmBsumRdsxDUWaJLe%2FvbfmuAdzJOCNw4oDtndlAOMZP0O5n1qaj8bO2RcRGhAVciMzwichLFjUQEDzoqxeilW%2F86Wjc7yZ3Jj467IdUJFrfywsi2VGMG993J3fGBKfXvFUSudwKj7RakPS7vPQRfWBZFnwVEsKNv58TrnjJtkYnlVXF2geq%2B057llH7Wn4A0s%2FdxQguZ4pu7SSWfi97SWkHhPlpNc0V7ReD6Iviw5S7lYsmc1YoMl72KiqNSQ%3D%3D%7Ctkp%3ABk9SR9Tb4Y6iYQ

[coppercone2]

UNFORTUNATELY 90V FALLS INTO A NARROW REGION OF ELECTRICAL PHYSICS PARAMETERS (89.71231V - 91.3014V) THAT JUST DO NOT ALLOW COMMUTATION TO OCCUR.

[TheMG]

No, not without re-designing half the power supply (including re-winding the transformer).

Would suggest looking for a DC-DC boost converter capable of the voltage you need instead, and run that off your low voltage power supply.

[Mechatrommer]

UNFORTUNATELY 90V FALLS INTO A NARROW REGION OF ELECTRICAL PHYSICS PARAMETERS (89.71231V - 91.3014V) THAT JUST DO NOT ALLOW COMMUTATION TO OCCUR.

sounds BS to me. any reference?

[inse]

Where’s your joke detector?

[Zero999]

When I needed that voltage range for a project, I bought two 48VDC power supplies and connected them in series. I added a diode in reverse parallel with each output, to protect it against reverse polarity, in case the other one shut down or current limited.

[Nominal Animal]

If you look at e.g. Mean Well AC-DC supplies, they tend to top out at 48V because they tend to be universal (85 - 264 VAC, 120 - 370 VDC).  For similar reasons, there does not seem to be too many AC-DC or DC-DC supplies with output in the range 55-100V.

I believe (but check with the more experienced members here, I'm just a hobbyist) that using two Class II isolated 48V supplies, like Mean Well HDR-15-48 (DIN rail mountable units that you can buy from e.g. TME for 16€ apiece, or Mouser for 17.25€ apiece) in series would give you 96 VDC.  Each can be adjusted between 43.2V and 55.2V, so you should be able to adjust the combination between 87V and 110V.

I also asked TI Webench on suggestions for a 5-12VDC to 96VDC 100mA boost converter, and it provided several designs based on chips like LM51561H that would yield better than 85% efficiency at 60mA.

Where’s your joke detector?

I COULDN'T HEAR IT GO OFF BECAUSE OF THE SHOUTING GOING ON.

[TimNJ]

Most commercial power supplies top out at 48-56VDC due to the 60V SELV requirement. Staying under this voltage makes your system design and regulatory process much easier. You may of course need an internal voltage above 60V for whatever reason. If so, proper precautions need to be taken to prevent user from coming in contact with this potential. That’s the reason most power supplies manufacturers don’t bother above 60V.

[jonpaul]

48V = std telcom battery plant

Very commpon in all sizes, 2X in series.

Some can adjust set both at 45V

DONE!

Jon

[Zoli]

You can get 56V POE supplies; quick search gave me 120W brick.
90V: fly-back with one of the 1:10-12 small(Pulse or Würth) transformers.

[Terry Bites]

You have failed to define a temperature at which this band is valid.
Clearly it is subject to drift. Imbecile!

[Zero999]

Most commercial power supplies top out at 48-56VDC due to the 60V SELV requirement.

120VDC is the actual limit for SELV, but it does require basic insulation, because it still presents a hazard, just less so than the mains.

[james_s]

That depends on how much engineering work you want to do. Keep in mind that if you modify it for higher voltage, the current it can deliver will fall accordingly.

It's relatively easy to find surplus telecom "rectifiers" which are really just 48VDC SMPS's. You could probably tweak one of those up to 56V fairly easily. Or you could do what I've done with obsolete cordless tools and just install XT60 connectors and use cheap LiPo packs meant for model airplanes and drones and such.

[Zero999]

I used two DIN rail mount power supplies, in series, with anti-parallel diodes, in an enclosure.

Here's an example.
https://uk.rs-online.com/web/p/din-rail-power-supplies/2358693

[Someone]

Most commercial power supplies top out at 48-56VDC due to the 60V SELV requirement.

120VDC is the actual limit for SELV, but it does require basic insulation, because it still presents a hazard, just less so than the mains.

Depends which standard you refer to, Australian AS3100:
SELV "40V between conductors"

IEC/EN/AS/etc 61010
70V DC dry, 35V DC wet, or current (more complex)

Now with more modern IEC/EN/AS/etc 62368:
ES1 DC 60V or 0.5mA

[Zero999]

Most commercial power supplies top out at 48-56VDC due to the 60V SELV requirement.

120VDC is the actual limit for SELV, but it does require basic insulation, because it still presents a hazard, just less so than the mains.

Depends which standard you refer to, Australian AS3100:
SELV "40V between conductors"

IEC/EN/AS/etc 61010
70V DC dry, 35V DC wet, or current (more complex)

Now with more modern IEC/EN/AS/etc 62368:
ES1 DC 60V or 0.5mA

Yes I got ELV confused. Extra Low Voltage is always below 120V, or 50VAC, but SELV varies, depending on the standard.

[langwadt]

That depends on how much engineering work you want to do. Keep in mind that if you modify it for higher voltage, the current it can deliver will fall accordingly.

It's relatively easy to find surplus telecom "rectifiers" which are really just 48VDC SMPS's. You could probably tweak one of those up to 56V fairly easily. Or you could do what I've done with obsolete cordless tools and just install XT60 connectors and use cheap LiPo packs meant for model airplanes and drones and such.

quite few places that sell stepper motors and drivers have 60V supplies