Super wide range PSU

[tvtech]

'Cuz the US gov't won't fund NASA to do it. Everybody knows that!

Except me. I have learned. Thanks throb.

Regards,
tv

 

[tcmtech]

Sorry not buying it. I have worked around industrial systems my entire life and to this day I have yet to ever see any system that did not already have one or more of the standard off the shelf system voltages active in it that was not able to be easily tapped into to add any type of small accessory power pack for other purposes.

As far as small and cheap goes for supplying 5 volts at a few watts of power to something I quite regularly buy the small 12 - 24 VDC cigarette lighter USB adapters for the
DC work and for the AC powered stuff I get the little power cubes that are about 1" cubed that take any voltage from a 85 - 250 VAC and put out 5 VDC @ 1 - 2 amps. Both units can be bought for less than $3 each.

Now with any system that does not already run on those two ranges of input power there is more than likely some internal subsystems that do operate on power that is in one of those ranges which gives you a tie on point that will work as a power source just the same.

My point is no matter what the higher power input voltage was there is almost always some electronics that are running off of a common lower AC or DC power buss that can be tied into.

 

[Cicero]

Sorry not buying it. I have worked around industrial systems my entire life and to this day I have yet to ever see any system that did not already have one or more of the standard off the shelf system voltages active in it that was not able to be easily tapped into to add any type of small accessory power pack for other purposes.

As far as small and cheap goes for supplying 5 volts at a few watts of power to something I quite regularly buy the small 12 - 24 VDC cigarette lighter USB adapters for the
DC work and for the AC powered stuff I get the little power cubes that are about 1" cubed that take any voltage from a 85 - 250 VAC and put out 5 VDC @ 1 - 2 amps. Both units can be bought for less than $3 each.

Now with any system that does not already run on those two ranges of input power there is more than likely some internal subsystems that do operate on power that is in one of those ranges which gives you a tie on point that will work as a power source just the same.

My point is no matter what the higher power input voltage was there is almost always some electronics that are running off of a common lower AC or DC power buss that can be tied into.

Not buying it? Didn't know I was selling something.

I think I get what you're saying and I understand that, but I think you're still missing what I'm asking, and perhaps taking it the wrong way. I'm trying to stay away from extra power connections to the device which is what I assume you're suggesting here...with having an 2 AC inputs (1live, 1 neutral), and maybe an extra 2 DC connections. That would be 4 power connections to the device, and the user connects the appropriate power to the appropriate connections. Fair enough.

But what I'm proposing, is that there are only 2 power connections to the device, no exceptions. Say V+ and V-. And I want to be able to connect any type of input power (12-48V DC, 12-264V AC) to those same connections, preferably with no user fiddling involved.

 

[throbscottle]

so, it's been establilshed that wide-range ac or dc psu's are easy. For what you want then have an "ac or dc" detector, then a bit of logic switches the input via a n/o relay to the appropriate converter. Have you considered if this would pass safety regulations though?

 

[Cicero]

so, it's been establilshed that wide-range ac or dc psu's are easy. For what you want then have an "ac or dc" detector, then a bit of logic switches the input via a n/o relay to the appropriate converter. Have you considered if this would pass safety regulations though?

Yeah thats it, well its the only way I'd think it could perhaps work as well.

Getting it passed through safety approvals could be a nightmare you're right, I can't imagine trying to explain it to them, haha.

 

[blueroomelectronics]

If it were possible to do it cheap, small and safely you'd see such devices on the market.

 

[Cicero]

If it were possible to do it cheap, small and safely you'd see such devices on the market.

Meh, not necessarily.

Like many people have said, "whats the point?" That's a fair question, and its only because I want to consolidate psu's that I have a need, but there are not many people/devices that would require such a wide input range, at such low output power as well. So why would they be on the market then if there isn't a large need?

Secondly, if it is just a case of creating some 'smart switch' circuitry to either select the AC psu or DC psu, how much size and cost would that really add?

 

[ronsimpson]

'smart switch' circuitry to either select the AC psu or DC psu

You can send DC into a AC power supply.

whats the point?

Inventory control

12-250V ad, dc

That is "a bridge too far". (movie)

 

[blueroomelectronics]

Meh, not necessarily.

Not meh at all, from a manufacturing standpoint this would save them plenty vs having to manufacture two separate devices.

Have you ever seen anything even remotely close to what you're looking for? I haven't. But if you do post a link I'd be interested.

 

[Cicero]

Yeah, I reckon its necessary to revise the input specs:
90-264VAC and 12-60VDC

 

[Cicero]

Not meh at all, from a manufacturing standpoint this would save them plenty vs having to manufacture two separate devices.

Have you ever seen anything even remotely close to what you're looking for? I haven't. But if you do post a link I'd be interested.

Check back a few posts of mine, I posted a Ti solution thats damn close.

EDIT: Thanks for the dislike

 

[throbscottle]

You can send DC into a AC power supply.

Good point, I've heard about that before. With an SMP it rectifies the AC mains anyway, and the chopper makes the AC for you. So you would just need to optimise it to work with the voltages you require, and change "can" into "designed for". Could maybe get rid of "smart switching" altogether - or maybe it just be between a couple of transformer taps to cope with the extremes.

I'm thinking now (owwwwwch!) my daughter & son in law have (or had) a powered cool box for camping. It can run on 12v vehicle or on 240VAC. It has 2 inputs, a DC power jack and a figure of 8 for mains. I guess it has a 12v motor and the mains input is to a psu. Wouldn't surprise me if you get 12v at the DC jack when it's running on mains.

But what this gets me round to is, it has 2 sockets to be able to run on 2 different power sources. You are thinking of having a single socket to run both, so, well we've established you CAN, but is it a good idea to do so? Confused customers for one thing, and you would still need to produce 2 types of cable even though they have the same appliance connector, they would need a different power connector at the other end, and this leads me to think there are safety implications here - at least as far as the regulatory people are concerned. So you may as well have 2 input sockets anyway.

 

[ronsimpson]

Yeah, I reckon its necessary to revise the input specs:
90-264VAC and 12-60VDC

Does the 12-60 need isolation?

You might look at what voltage UL regulates. I think at and below 48V you don't have much trouble. If the price of getting through UL is 1/4 as much you might want to rethink the voltage range.

 

[tcmtech]

Again everything goes back to the practical application of it Vs what already on the market of which there are already a pile of dual universal input to 5 VDC USB output power supplies all over the place.

They come with a common 12 - 24 VDC automotive flip out power port plug input and a flip out 120 VAC plug built into one unit and most of them I have seen will work on any input voltage from common 12 - 24 VDC or 85 - 250 VAC power source and cost around $5 - $10 at most any auto parts store or gas station.

Here is just one of a few dozen versions of the device.

Pretty sure that if you needed a mass quantity of them to work on an even wider input AC and DC voltage ranges the manufacturers could easily tweak their designs to handle it. No point in re inventing an already off the shelf item that is mass produced.

 

[Cicero]

Your safety concerns are valid, for sure, and I can't answer them at this point as I'm not even sure myself . The DC unit wouldn't need isolation, but I'm not sure whether the AC side does or not.

tcmtech : Agreed. I like those car adapters, and I reckon I'll look to buy a few to see what they're doing inside - perhaps tweak what they do.

ronsimpson : Thanks, Ti really do have some good DC buck solutions.