USB powerbank with pure 5V output

[new6ton]

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?

Above it is the USB input connected to the computer USB output. Can't anyone recognize what is this pluggable battery pack?

 

[anorlunda]

When I go camping, I bring an inexpensive battery pack to charge USB devices. It has two output ports, 1A and 2A.

 

[Baluncore]

Can't anyone recognize what is this pluggable battery pack?

That appears to be an EnSpectr proprietary product as it has the name embedded in the plastic moulding.

 

[Baluncore]

You could beg or buy a cheap used cordless drill with a charger and battery. Pick a standard system that uses batteries available at low cost on eBay etc.

Then cut off the motor body, keeping the handle with the battery socket. Put a 5 volt regulator in the handle with a DC lead and connector to the instrument.

 

[rbelli1]

https://www.digikey.com/en/articles/techzone/2017/mar/designing-in-usb-type-c-and-using-power-delivery-for-rapid-charging

According the above paper you should be able to get >1A out of your USB-C port. Then you have the full sized one for the data connection. I would suspect the full sized one is also able to provide >1A but that is not guaranteed. If it has the + sign next to it then most likely it can. See the lower right of the linked picture. These ports support the USB2 charging specification and will give you enough power.

BoB

 

[new6ton]

https://www.digikey.com/en/articles/techzone/2017/mar/designing-in-usb-type-c-and-using-power-delivery-for-rapid-charging

According the above paper you should be able to get >1A out of your USB-C port. Then you have the full sized one for the data connection. I would suspect the full sized one is also able to provide >1A but that is not guaranteed. If it has the + sign next to it then most likely it can. See the lower right of the linked picture. These ports support the USB2 charging specification and will give you enough power.

BoB

But as I have mentioned before. My Microsoft Surface Pro 2017 has only one USB3 port and it is not USB-C and it is already used up plugging it to the spectrometer USB input. Here is a picture of the MS tablet:

It comes from https://www.windowscentral.com/why-no-usb-type-c-new-surface-pro explaining why the new surface pro has no USB type c. But there is finally an adaptor to connect the proprietary ms port to type c. https://www.windowscentral.com/first-look-surface-connect-usb-c-adapter

Who owns one. Is it designed to connect and to power other units like regular USB-type c?

 

[new6ton]

When I go camping, I bring an inexpensive battery pack to charge USB devices. It has two output ports, 1A and 2A.

View attachment 251451

The surface connect to type c costs $80 so I guess I'll just use a battery pack like above as suggested.

Now for permanent use. Won't the battery pack like the above be safer to use than an AC (Alternating Current connected directly to transmission line) adaptor like this?

I mean, can't any defect happens (like open or short in the wiring in the primary winding inside) the can cause secondary to have full 110 voltage instead of 5 volts? So won't a battery pack just be safer to use? As the worse that can happen in the latter is just 9 volts going to output instead of 5 volts?

 

[Baluncore]

I mean, can't any defect happens (like open or short in the wiring in the primary winding inside) the can cause secondary to have full 110 voltage instead of 5 volts? So won't a battery pack just be safer to use? As the worse that can happen in the latter is just 9 volts going to output instead of 5 volts?

It is important when catastrophising to pick probable scenarios. The probability of theft is significantly greater than the probability of a AC line to DC output breakdown in a switching converter.

Is the instrument insured against theft? What about electrical failure? or electrostatic damage during a thunderstorm?

 

[new6ton]

It is important when catastrophising to pick probable scenarios. The probability of theft is significantly greater than the probability of a AC line to DC output breakdown in a switching converter.

Is the instrument insured against theft? What about electrical failure? or electrostatic damage during a thunderstorm?

The $16000 lab equipment is not insured against anything. An AC/DC switching adaptor has no primary and secondary winding. I think it's all diodes and ICs? Usually if the adaptor got defective, perhaps it would just cease to output any voltage or would the full 110v appear in the secondary? Anyone familiar with AC/DC switching adaptor?

 

[Baluncore]

Anyone familiar with AC/DC switching adaptor?

Yes.
The AC input is rectified to HV DC between 150V and 340V. That is switched through the HF transformer primary. The secondary voltage is rectified and compared with a reference. A signal is sent back to the HV switch via a transformer or opto-isolator to control the switching and so regulate the output voltage.

An AC/DC switching adaptor has no primary and secondary winding.

An AC/DC switching adaptor contains a high frequency ferrite core transformer that can be very small because it operates at about 100kHz. That transformer isolates the input from the output. The design of such a module has critical safety requirements in the PCB and transformer design to prevent breakdown between the AC and DC sides of the adaptor.

 

[davenn]

The $16000 lab equipment is not insured against anything.

OMG ... Seriously ??
That's your number 1 concern

 

[new6ton]

Yes.
The AC input is rectified to HV DC between 150V and 340V. That is switched through the HF transformer primary. The secondary voltage is rectified and compared with a reference. A signal is sent back to the HV switch via a transformer or opto-isolator to control the switching and so regulate the output voltage.

An AC/DC switching adaptor contains a high frequency ferrite core transformer that can be very small because it operates at about 100kHz. That transformer isolates the input from the output. The design of such a module has critical safety requirements in the PCB and transformer design to prevent breakdown between the AC and DC sides of the adaptor.

I have about 10 pieces of generic china made $4 AC/DC switching adaptor to power my CCTVs. None of them breaks down. Has anyone encountered one in their collection that breaks down? What happens to it? Maybe the natural design of such is very robust to breakdown or maybe there are already in some kind of IC integrated? If anyone has a good illustration how the inside of one looks like. Would appreciate it to see the picture and/or diagram.

 

[anorlunda]

I have about 10 pieces of generic china made $4 AC/DC switching adaptor to power my CCTVs.

Many people in the modern world have a cardboard box holding dozens of such devices. They are outnumbered only by ants.

Of course they fail, but almost always they just stop working. I can't recall a personal experience of one of those things damaging the equipment they power.
Have you ever personally heard of someone frying their cell phone with a phone charger? I'm sure it must have happened somewhere sometime, but it is so rare as to be negligible.

At your work, many (perhaps all) employees have a laptop powered by an external AC/DC converter. That adds up to lots of $$ for the company. Have you heard of any in your company being damaged by the AC adapter?

We think your concern is exaggerated.

 

[new6ton]

Yes.
The AC input is rectified to HV DC between 150V and 340V. That is switched through the HF transformer primary. The secondary voltage is rectified and compared with a reference. A signal is sent back to the HV switch via a transformer or opto-isolator to control the switching and so regulate the output voltage.

An AC/DC switching adaptor contains a high frequency ferrite core transformer that can be very small because it operates at about 100kHz. That transformer isolates the input from the output. The design of such a module has critical safety requirements in the PCB and transformer design to prevent breakdown between the AC and DC sides of the adaptor.

What is this "critical safety requirements in the PCB and transformer design to prevent breakdown between the AC and DC sides of the adaptor" (switching adaptor)? How can $3 generic china swtiching adaptors be so robust? Is it just an IC inside or main component that they acquire elsewhere?

 

[Baluncore]

How can $3 generic china swtiching adaptors be so robust?

The transformer is sufficiently well insulated internally to be safe. It is called engineering.
The Chinese are not idiots. If adaptors failed the company and their insurers would go broke. Natural selection ensures that only safe and reliable adaptors that meet the standards remain in the market.

 

[new6ton]

The transformer is sufficiently well insulated internally to be safe. It is called engineering.
The Chinese are not idiots. If adaptors failed the company and their insurers would go broke. Natural selection ensures that only safe and reliable adaptors that meet the standards remain in the market.

https://image-us.bigbuy.win/upload/image/assistant/GS01058/GS01058-3.JPG
I tried to find internal schematic of an AC/DC switching adaptor at google just out of curiosity. I found one. Is the transformer above an isolated transformer or autotransformer? What does DC36V-5 mean?

 

[Baluncore]

Is the transformer above an isolated transformer or autotransformer? What does DC36V-5 mean?

The transformer will certainly be isolated. It is not an autotransformer.

You have not identified the product that is pictured. DC36V-5 is probably an internal stock control number. It might be the 5'th version of transformer used in product DC36, or it might identify the whole converter assembly.

 

[Tom.G]

At least as likely, the label could indicate the output rating, 36VDC @5Amps.
Or 36Watts 5VDC.

A clue is the voltage rating of the capacitors at the DC output, 50V... so more likely 36V output.

 

[new6ton]

At least as likely, the label could indicate the output rating, 36VDC @5Amps.
Or 36Watts 5VDC.

A clue is the voltage rating of the capacitors at the DC output, 50V... so more likely 36V output.

The circuit is really inside of most generic china (or even american) made AC/DC switching adaptors that usually have 100 to 230 volt input and 12 volts outputs? Why is it called switching? what switches?

 

[Asymptotic]

The circuit is really inside of most generic china (or even american) made AC/DC switching adaptors that usually have 100 to 230 volt input and 12 volts outputs? Why is it called switching? what switches?

The way a SMPS (Switch Mode Power Supply) operates makes it possible to allow a wide range of AC input voltages.

Output voltage is up to the designer. 12V is often seen because a lot of devices use it, but it can be whatever is needed, and often several discrete voltages are generated. Your computer power supply is a prime example - +12V, -12V, +5V, and +3.3V for the ATX standard.

There are a lot of ways to build a SMPS, depending on it's purpose and how much it costs. Wikipedia has an overview. https://en.wikipedia.org/wiki/Switched-mode_power_supply#Types

What device(s) switch and how they switch depends on the topology. This video tutorial describes a SMPS using one of these topologies.

 

[Baluncore]

At least as likely, the label could indicate the output rating, 36VDC @5Amps.
Or 36Watts 5VDC.
A clue is the voltage rating of the capacitors at the DC output, 50V... so more likely 36V output.

There are too many possibilities, with insufficient information to make any rational deduction.
There is even less evidence that guessing might actually help anyone. No one needs to know.

Why is it called switching? what switches?

This is not the place for a beginners question driven tutorial on a subject that takes a year to understand properly.
As a novice, you need to trust the technology, or begin a study of switching converters.
Follow the tutorial in the above post or go to;
https://en.wikipedia.org/wiki/Switched-mode_power_supply

 

[new6ton]

There are too many possibilities, with insufficient information to make any rational deduction.
There is even less evidence that guessing might actually help anyone. No one needs to know.This is not the place for a beginners question driven tutorial on a subject that takes a year to understand properly.
As a novice, you need to trust the technology, or begin a study of switching converters.
Follow the tutorial in the above post or go to;
https://en.wikipedia.org/wiki/Switched-mode_power_supply

You are right. But which is safer to use on a very expensive laboratory equipment for permanent lab setting (to protect the investment). A DC/AC switching adaptor or a 12v battery and 12vto 5 v DC converter like the following:

https://www.meanwell.com/webapp/product/search.aspx?prod=DDR-15

click image to enlarge it

 

[Baluncore]

But which is safer to use on a very expensive laboratory equipment for permanent lab setting (to protect the investment). A DC/AC switching adaptor or a 12v battery and 12vto 5 v DC converter like the following:

They are equally unlikely to cause an over-voltage problem.
It is 100 times more likely that expensive equipment will be stolen.

 

[new6ton]

They are equally unlikely to cause an over-voltage problem.
It is 100 times more likely that expensive equipment will be stolen.

But technically. The DC to DC converter would be more safe because in the even the converter is damaged, the overvoltage would only be 9V or 12V (the battery) instead of full 110 volts. In average use. You are right that it is 100 times more likely it would be stolen.

But it would matter if it would be used as a tactical equipment, to detect chemical warfare residue or explosive traces. In such case then the DC to DC converter would be more appropriate. Correct? Not that I'll use it on them but just asking. And all spectrometers are controlled for export to North Korea because they have military use too.

 

[davenn]

The DC to DC converter would be more safe because in the even the converter is damaged, the overvoltage would only be 9V or 12V (the battery) instead of full 110 volts.

HUH ?? where did you get the 110V from in a DC - DC converter ??

 

[Baluncore]

But technically. The DC to DC converter would be more safe because in the even the converter is damaged, the overvoltage would only be 9V or 12V (the battery) instead of full 110 volts.

No.
110 Vrms AC is rectified to 155 V DC. We still have 240 Vrms which gives 340 V DC. I have been designing, building and servicing switching supplies for over 40 years. A failure in the HV circuit has always blown the fuse, sometimes it has shattered semiconductors, but it has never jumped to the isolated low voltage output.

On the other hand, a DC-DC converter is usually not isolated. A short circuited switch failure is more likely to connect the input voltage to the output through the inductor. That over-voltage should be detected by a crowbar circuit which will short the output and so protect the load, quickly blowing the fuse.
https://en.wikipedia.org/wiki/Crowbar_(circuit)

 

[rbelli1]

the overvoltage would only be 9V or 12V

Which may be just as destructive depending on the equipment as 115VAC.

a DC-DC converter is usually not isolated.

Meanwell DDR ones are.

If you are still concerned, get a medical power supply with a cardiac float rating.

https://recom-power.com/en/applications/medical/medical-power-supplies.html?0

You can literally bet your life on that not frying the equipment.

BoB

 

[new6ton]

HUH ?? where did you get the 110V from in a DC - DC converter ??

I meant "the overvoltage would only be 9V or 12V (the battery) instead of full 110 volts (if an AC/DC switching adaptor used, at least I thought so initially).

Btw. the Spectrometer I have is mostly optics. The only components that need the 5V is the laser and CCD. The laser can be replaced by a hole at the side of the unit. Does anyone know what kind of CCD has this spec?

Linear CCD Array	Linear CCD Array
Pixel Number	3648
Pixel Size	8 μm x 200 μм
Dark Current	630 e/pixel/s
Readout Noise	30 e rms
Dynamic Range	2100
Max Quantum Efficiency	90%
Integration Time	10 ms – 500000 ms

This is what composes a raman spectrometer (mine doesn't have a TE cooler or any fiber optics, the one below costs $65,000). Can you make the components less than $16,000? I think my supplier can assemble them for less than $1,000. What is your opinion? Note the software is only one time deal for all their products. It's like Apple creationg the IOS for all Iphones units and not each individually programmed.

 

[Tom.G]

Hamamatsu is a major supplier of line sensors, TI used to make some but I couldn't find any in a brief search. Since line sensors are used in flatbed scanners, other possibilities are HP (Hewlett-Packard) and Canon.

Here is a link to the Hamamatsu catalog:
https://www.hamamatsu.com/resources/pdf/ssd/image_sensor_kmpd0002e.pdf
above found with:
https://www.google.com/search?&q=Hamamatsu+ccd+linear+sensor
Cheers,
Tom

 

[sophiecentaur]

If the spectrometer is that expensive then why not spend a bit more money and use the manufacturer's recommended supply unit? If you are really worried about what could happen when there is a power supply fault then read the bit in the manual which tells you about the warrantee being void if you don't use the right PSU.