Question Voltage supply issue related to NUC PC Core i7

[zainiii]

Hi Everyone,

My name is Kamran, and I am a PhD student. I want to build a compact system that includes many components along with the NUC PC Core i7-12700H for medical purposes. The NUC PC works fine with the power cable I received from the company, which has the following specifications: 19V, 6.32A, and 120W, and it operates on AC 80-240V. However, I want to create a compact system that incorporates the NUC PC with other instruments without using power cables for any of the components, in order to save space and make the system very compact. Instead, I would like to use a multiple DC output AC to DC converter to provide power to the various components and instruments.

The issue is that the NUC PC requires 19V DC, and I haven't found a multiple-output AC to DC power converter that provides 19V DC. After extensive research, I concluded that I could use a 15V DC power supply with a current rating of 8A, as I was unable to find any multiple-output AC to DC converter that offers outputs of 18V, 19V, or 20V.

I’m unsure whether this option would be suitable for running the NUC PC effectively or if it would create problems. If there are any experts here, please guide me.

Your assistance in this matter would be greatly appreciated.

 

[Eximo]

I suppose it depends on how compact you are wanting. Plenty of modular bench PSUs that can have multiple DC outputs. Though that would be very expensive.

If the input is fine with the lower voltage, you need only be aware that running the extra current through the VRMs in the system at peak power will shorten their operational life through higher temperatures. Of course that assumes you ever get anywhere near 120W in operation. As long as they are capable of dissipating sufficient heat for your load, they may last more than long enough.

I don't think you will find anyone who has had a 12700H NUC long enough that also uses a 15V power supply.

 

[zainiii]

I suppose it depends on how compact you are wanting. Plenty of modular bench PSUs that can have multiple DC outputs. Though that would be very expensive.

If the input is fine with the lower voltage, you need only be aware that running the extra current through the VRMs in the system at peak power will shorten their operational life through higher temperatures. Of course that assumes you ever get anywhere near 120W in operation. As long as they are capable of dissipating sufficient heat for your load, they may last more than long enough.

I don't think you will find anyone who has had a 12700H NUC long enough that also uses a 15V power supply.

Dear Sir,
Thank you very much for providing me with the valuable information.
My setup is not large; it's a compact one. My NUC PC will be measuring data from two sensors using Spyder IDE, and a software for measuring spectrometer data will also be used. All these results will be displayed on a connected 7-inch LCD. This work will be done by the NUC PC. I will only use it for testing, maybe twice a week for 1 to 2 hours, and not permanently all the time. I believe its not a big setup to draw large amount of power consistently.

 

[Misgar]

without using power cables for any of the components

I'm having difficulty imagining a system that will work without any power cables, unless everything runs on internal batteries.

I was unable to find any multiple-output AC to DC converter that offers outputs of 18V, 19V, or 20V.

Yet here you mention AC-to-DC converters, so presumably you do intend using power cables after all? Did you consider "programmable" modules with controllable output voltages to obtain 19V?

After extensive research, I concluded that I could use a 15V DC power supply with a current rating of 8A

Was this "extensive" research based on the permitted input voltage range of the NUC, as specified by the manufacturer, or were you simply multiplying Volts and Amps to end up with the same output power from a 15V supply as from the 19V supply provided with the NUC?

Prior to the advent of USB-C charging, 19.0V DC was a very common supply voltage for laptops. Some laptops had 18.0V power bricks, others 19.5V or 20V bricks. As a rough rule of thumb, I would not specify or use a power brick, if its rated output exceeded +/- 1.0V over the normal input, e.g. no higher than 20.0V and no lower than 18.0V for a 19.0V supply.

As an electronics design engineer, I would not connect a significantly lower 15V DC supply to a computer rated at 19V. It's asking for trouble and you could end up with a dead NUC. Trying to RMA a damaged unit might be difficult, if examination showed an unusual failure mode, due to the wrong supply voltage.

As @Eximo says, the NUC's internal DC-to-DC converter could draw significantly higher currents at 15V DC, which might exceed the ratings of the MOSFETs in the SMPSU.

for medical purposes

You should be aware that equipment used in hospitals near patients, must adhere to stricter safety codes than general office equipment. All computer equipment and especially switched mode power supplies, emit a broad range of radio frequency interference. There are also the mains isolation requirements to consider near patients, where fluid spillage on to equipment may be involved.

You really do not want to face a board of enquiry, when your uncertified equipment results in the death of a patient, if their pacemaker stops working due to RFI or a pain killer infuser gives an overdose.

Before proceeding, I suggest you contact the safety representatives at the medical establishment where you propose using your NUC system and check if it conforms with safety legislation.

https://eepower.com/industry-articles/iec-60601-1-and-power-supplies-for-medical-devices/#

 

[Eximo]

I believe the intention is to use a single power supply, with multiple outputs, to run all the attached equipment. At least that was how I read it.

Modular bench supplies are a thing as mentioned. Could also start with a higher voltage supply and get adjustable buck converters for everything downstream.

He says compact, but I don't know what that means for his application.

 

[Misgar]

I believe the intention is to use a single power supply, with multiple outputs, to run all the attached equipment. At least that was how I read it.

That was my understanding too.

My main concern is whatever the OP puts together, if the "medical" equipment is being used in a hospital near patients, to stay within the law, you would need to obtain "Type Approval" (UL/CE, etc) for Medical Equipment.
https://www.qualio.com/blog/fda-medical-device-classes-differences
https://www.gov.uk/guidance/medical-devices-how-to-comply-with-the-legal-requirements

Of course, I have no idea what safety legislation applies where the OP lives, nor if the equipment will be used near patients or not. I'm just pointing out the pitfalls of using "office" equipment in a "medical" environment.