USB powerbank with pure 5V output

[new6ton]

I guess USB powerbank have switching power supply for the 5V output? I need a pure 5V power bank that doesn't use switching power supply but just pure output like the 3.7v lithium battery in cell phone. And why doesn't lithium battery doesn't produce 5 volt dc output?

 

[davenn]

And why doesn't lithium battery doesn't produce 5 volt dc output?

because of the chemistry

I need a pure 5V power bank that doesn't use switching power supply

use a linear regulator ... a little lossy in comparison to a switching (buck converter) regulator
but at least it smoothSo, why do you need a very smooth supply ?
maybe it doesn't need to be as smooth as you imagine ?Dave

 

[Torbert]

For temporary (3 hour) low power (.06 w) output I used lithium ion (3.7v) in series with an alkaline (1.5v) battery for a five volt application. No recharging, or high power draw. I could have used a nickel hydroxide (1.2v) rechargeable but needed the full five volts. Mix and match is a very limited system for output power but can provide quite a variety of voltages.
Another project used a 13.8 volt DC power source, a full wave rectifier with a capacitor array minimizing ripples in voltage. This would output 400w of stable DC power. Inputting the proper resistance put the voltage anywhere from 0 to 13.8 volts.

Intended use makes all the difference in requirements.

 

[davenn]

For temporary (3 hour) low power (.06 w) output I used lithium ion (3.7v) in series with an alkaline (1.5v) battery for a five volt application.

I guess you have never heard of the "rule" about not mixing battery tupes ( chemistries) and voltages ?
It seriously is a bad idea

 

[anorlunda]

I need a pure 5V power bank that doesn't use switching power supply but just pure output

Why is that? I'm just curious.

 

[eq1]

So, why do you need a very smooth supply ?
maybe it doesn't need to be as smooth as you imagine ?

And just as important, over what frequency range?

In 2019 it's possible to get cheap supplies that switch at many MHz with lots of closed-loop gain into the 100s of KHz.

 

[new6ton]

Why is that? I'm just curious.

It's to power a very expensive laboratory equipment, a spectrometer so I can bring it outside with a laptop. The spectrometer says 5V, 1A at the back.

Currently, It's power via Meanwell adaptor (see picture):

I want very pure 5v output so it won't ruin the circuit inside. I heard ordinary USB powerbank has switching power supply, and not good as it's pure? Pure means like output from 3.7v lithium battery like used in cellphone, without any switching noises, etc.

 

[berkeman]

It's to power a very expensive laboratory equipment, a spectrometer so I can bring it outside with a laptop. The spectrometer says 5V, 1A at the back.

I want very pure 5v output so it won't ruin the noise performance of the circuit inside.

I corrected your post above.

The professional EE approach to these types of applications (as suggested already in this thread by @davenn ) is to use a higher battery source voltage (like 12V) with a DC-DC buck converter to make an intermediate voltage that a linear LDO then smooths out. I've used this topology for 80dB radio modems, for example.

 

[new6ton]

I corrected your post above.

The professional EE approach to these types of applications (as suggested already in this thread by @davenn ) is to use a higher battery source voltage (like 12V) with a DC-DC buck converter to make an intermediate voltage that a linear LDO then smooths out. I've used this topology for 80dB radio modems, for example.

I don't want to build anything. I just want to buy a readily available one. Any product one can suggest that outputs the most purest DC 5v ever? I don't want to build or use nontested ones because I don't want the voltage to suddenly rise to DC 10 volts or so and ruin the $16,000 spectrometer.

 

[berkeman]

I don't want to build or use nontested ones because I don't want the voltage to suddenly rise to DC 10 volts or so and ruin the $16,000 spectrometer.

So your are worried about overvoltage faults, not ripple voltage on the outputs? Lordy...

 

[new6ton]

So your are worried about overvoltage faults, not ripple voltage on the outputs? Lordy...

I'm just worried of anything that can ruin the circuit inside. I don't know what is the circuit inside but it's mostly the CCD and programmable microcontroller. Can't ripple voltage damage them?

 

[berkeman]

Buy a standard power supply product. Better yet, buy the standard power supply that the vendor sells for that instrument. What in the world is the problem here?

 

[new6ton]

Buy a standard power supply product. Better yet, buy the standard power supply that the vendor sells for that instrument. What in the world is the problem here?

The standard power supply is the AC adaptor. Remember I need the battery pack to carry it outside with my laptop into wine shops to scan the purity of their wines or contaminants. The manufacturer doesn't have battery pack.

 

[berkeman]

Ah, thank you. I understand better now. Can you post a picture and a link to the datasheet for the standard AC-DC power supply that the manufacturer supplies for this product? That will help us to point you to a compatible battery-powered supply.

Also, have you asked the product manufacturer about a battery-powered option?

 

[new6ton]

Ah, thank you. I understand better now. Can you post a picture and a link to the datasheet for the standard AC-DC power supply that the manufacturer supplies for this product? That will help us to point you to a compatible battery-powered supply.

I did. The AC adaptor for it is:

Also, have you asked the product manufacturer about a battery-powered option?

I asked. They don't have any battery pack and don't know how to suggest any.

 

[Baluncore]

Can't ripple voltage damage them?

That is a general power input. The instrument will have it's own internal supply regulation and protection. External noise +/- 0.25V, on the DC 5V supply will be unimportant.

When you are fearful of the unknown, find out what is going on. Read the specifications on the power input requirements.

Why will you not identify the make and model of the spectrometer?

 

[new6ton]

That is a general power input. The instrument will have it's own internal supply regulation and protection. External noise +/- 0.25V, on the DC 5V supply will be unimportant.

When you are fearful of the unknown, find out what is going on. Read the specifications on the power input requirements.

Why will you not identify the make and model of the spectrometer?

The model is this exactly. http://enspectr.com/portfolio/enspectr-r532/

 

[berkeman]

Ah, sorry, yes you did already post this. Since it's an AC-DC converter brick, it will have ripple on its output, so that shouldn't be an issue with your battery powered solution.

I would just use a medium-size 12V battery with an off-the-shelf 12V to 5V DC-DC converter circuit. 4A is a pretty high output current, so it may take some searching to find a good converter module.

How long do you need this instrument to run off of a battery supply?

 

[new6ton]

Ah, sorry, yes you did already post this. Since it's an AC-DC converter brick, it will have ripple on its output, so that shouldn't be an issue with your battery powered solution.

I would just use a medium-size 12V battery with an off-the-shelf 12V to 5V DC-DC converter circuit. 4A is a pretty high output current, so it may take some searching to find a good converter module.

How long do you need this instrument to run off of a battery supply?

It's 1A only, the back of the spectrometer has this label:

I want to run the battery pack less than 1 hour only.

 

[new6ton]

Ah, sorry, yes you did already post this. Since it's an AC-DC converter brick, it will have ripple on its output, so that shouldn't be an issue with your battery powered solution.

I would just use a medium-size 12V battery with an off-the-shelf 12V to 5V DC-DC converter circuit. 4A is a pretty high output current, so it may take some searching to find a good converter module.

It's risky to use 12V to 5V DC-DC converter circuit. What if the converter get broken in the future. Then the entire 12V will get into the unit and ruin it. It's too risky to ship a $16,000 unit around the world. I want a battery pack that doesn't use any converter but just pure 5V but worry free.

How long do you need this instrument to run off of a battery supply?

See photo and answer in last message.

 

[berkeman]

So a 12V, 1Ahr battery source would give you plenty of margin. What have you found for 12V input, 5V output DC-DC converter modules? If you use a simple 12V lead acid deep-discharge battery (like I do for my HAM radio setups), you can use a simple/cheap car battery charger to recharge the battery source...

 

[new6ton]

So a 12V, 1Ahr battery source would give you plenty of margin. What have you found for 12V input, 5V output DC-DC converter modules? If you use a simple 12V lead acid deep-discharge battery (like I do for my HAM radio setups), you can use a simple/cheap car battery charger to recharge the battery source...

View attachment 251432

See my last message. It's risky to use 12V to 5V DC-DC converter circuit. What if the converter get broken in the future. Then the entire 12V will get into the unit and ruin it. It's too risky to ship a $16,000 unit around the world. I want a battery pack that doesn't use any converter but just pure 5V but worry free.

And the 12v is too bulky.

The following is another product by another company that uses the same unit but made it portable. Did you see their battery pack? It's compact and small size. What could it be?

Remember since I didn't buy these specific products. They won't tell me what kind of battery or circuit for it. Its portable unit is $3000 more expensive.

 

[rbelli1]

Meanwell also sells switching converters meant for low voltage input that have a 5V output. If you can trust the very expensive device to the Meanwell AC power adapter you should be able to trust it to their other converters.

Meanwell DDR

BoB

 

[new6ton]

Meanwell also sells switching converters meant for low voltage input that have a 5V output. If you can trust the very expensive device to the Meanwell AC power adapter you should be able to trust it to their other converters.

Meanwell DDR

BoB

The problem is together with the 12V battery. It's bulky. I just need something like this:

Could it be just small AA rechargeable batteries? What combinations can produce 5V? Maybe 3 pieces of 1.5v AA small batteries or 4 pieces? Remember I think each is only 1.2V?

 

[rbelli1]

Get an 8 way AA battery holder and use 8 lithium batteries with the DDR switching power supply. If the device actually draws 1A continuously you should get 2 or so hours out of them. Alkaline will be half or less life if they work at all.

The other option is to take the cover off the device and examine the internal power supply to see what is the acceptable range of input voltages.

You could also get a usb to whatever plug your equipment is cable and use that. The pictured adapter is 2.1x5.5.

For Example

BoB

Edit: you may have to choose a charging port on the computer for it to allow 1A to be drawn from it. Most new laptops will have all of the port with this capability. Look for a + next to the usb port.

 

[new6ton]

to

Get an 8 way AA battery holder and use 8 lithium batteries with the DDR switching power supply. If the device actually draws 1A continuously you should get 2 or so hours out of them. Alkaline will be half or less life if they work at all.

The other option is to take the cover off the device and examine the internal power supply to see what is the acceptable range of input voltages.

You could also get a usb to whatever plug your equipment is cable and use that. The pictured adapter is 2.1x5.5.

For Example

BoB

Edit: you may have to choose a charging port on the computer for it to allow 1A to be drawn from it. Most new laptops will have all of the port with this capability. Look for a + next to the usb port.

It is not possible to open the cover because there is a warrantee seal that can void any warrantee if you open it.

My laptop or Microsoft Surface Pro doesn't have the 1A charging port. I think the manufacture told me one time the internal circuit got fried when someone tried to plug it to the USB. If the USB port has low amperage only and the device absorbs 1A, what would technically happen? Can it ruin either equipment?

 

[rbelli1]

It is not possible to open the cover because there is a warrantee seal that can void any warrantee if you open it.

OK. Best not do that then.

My laptop or Microsoft Surface Pro doesn't have the 1A charging port. I think the manufacture told me one time the internal circuit got fried when someone tried to plug it to the USB.

A USB charging port is a standard USB port that allows more than the old USB 1/2A specification to be drawn. The newest USB specification has explicit mention of this scenario. Ports that support more than 1/2A often have a + sign next to the USB symbol. Sometimes the internal plastic is orange or red. On very old devices you may be able to draw more than 1/2A even if there is no visible indication of that availability.

That said, if a USB device plugged into a USB port causes damage then something was broken before the plugging in happened.

There should be a protection device of some description on your surface and the port will shut down in an over-current situation. Being an expensive Microsoft product and an extremely expensive scientific equipment I would not worry about damage occurring. Over and under voltage and current protection will almost certainly be included in the design.

BoB

 

[new6ton]

OK. Best not do that then.
A USB charging port is a standard USB port that allows more than the old USB 1/2A specification to be drawn. The newest USB specification has explicit mention of this scenario. Ports that support more than 1/2A often have a + sign next to the USB symbol. Sometimes the internal plastic is orange or red. On very old devices you may be able to draw more than 1/2A even if there is no visible indication of that availability.

That said, if a USB device plugged into a USB port causes damage then something was broken before the plugging in happened.

There should be a protection device of some description on your surface and the port will shut down in an over-current situation. Being an expensive Microsoft product and an extremely expensive scientific equipment I would not worry about damage occurring. Over and under voltage and current protection will almost certainly be included in the design.

BoB

My Microsoft Surface Pro 201`7 tablet has USB 3.0 and here it is described as Maximum Current: 900mA.

https://en.wikipedia.org/wiki/USB_3.0
If the equipment draws 1A or more, the USB 3.0 has current limiter of some sort?

Added: I couldn't use the USB 3.0 in the Microsoft Surface Pro because it has only one USB which is to connect to the unit. So there is no 2nd USB for the power. The Microsoft Surface 2019 has this specs:

One full-size USB 3.0
Mini DisplayPort
Headset jack
Surface Connect
microSDXC card reader

But still I want to know what would happen if say an average PC USB is only say 1A and you draw 4A, what would happen to the USB? Just for stock knowledge.

 

[Asymptotic]

I guess USB powerbank have switching power supply for the 5V output? I need a pure 5V power bank that doesn't use switching power supply but just pure output like the 3.7v lithium battery in cell phone. And why doesn't lithium battery doesn't produce 5 volt dc output?

I'm not seeing the need for completely ripple-free voltage. The Meanwell GS25E05-P1J is a switching power supply rated 5V, +/-5% load regulation, 0 to 4 amp output with up to 50 mV peak-to-peak ripple/noise. The spectrometer requires 5VDC at 1 amp.

Wouldn't any commercially available USB powerbank capable of supplying 5V at 1A at 50 mVp-p or less ripple (with enough mAhr capacity to supply power for the required amount of time before recharging is needed) do the job?

 

[Rive]

It's 1A only, the back of the spectrometer has this label:

I want to run the battery pack less than 1 hour only.

Well: sorry to say this, but your very best (!) choice is exactly an USB power bank: preferably with a 2A output port.
It is also the most safe for this role.

If you are worried, then pick one which can manage multiple outputs simultaneously and connect a mobile phone (or any useless USB gizmo) on the other port. That'll do as an overvoltage protection.

Any homemade stuff will be just less safe.

If you want to give even more security to the thing then get something like this: it is unnecessary, but can give you the feeling of security anyway. By the way: above that 5V input that is an USB in- or output?