Hello. I'm trying to build this NAS project using my HP mini pc. The creator of the project used 2 power supplies : 1 x original PSU for the Pc, 1 x 12v 6A PSU for powering the HDDs. My plan is to use a single HP 19.5v 10.3A PSU and a 12V step-down converter for the HDDs but I would like to seek advice first to make sure I'm not damaging anything or burning the house down.

Parts list :

• HP PSU
• 10A Step-down converter
• 5525 to Sata converter

I was looking for a panel mount solution for the 7.4x5mm stock barrel plug for a clean entry into the case and splice the wires to go to the converter but couldn't find anything. I'm open to using a different connector but I have no idea where to look for this kind of application. It needs to be a 3 pin connection.
Since this will be on 24/7 I would like to know how the efficiency is affected. I have a basic understanding of how these things work so feel free to tell me if it's stupid.

 

Really a 10 amp buck converter is quite a large step down. My choice would be just run with an ATX PSU. They are common and inexpensive. Rough estimate is a typical HDD requires about 25 watts at spin up and then only about 8 watts maximum while running. How many drives are you planning to run? How much current would your buck converter have to deliver allowing for about a 20% overhead?

ATX hard disk drives (HDDs) typically use two primary voltages: 12V and 5V. The 12V line powers the motor that spins the platters, while the 5V line powers the logic circuits and actuator arm.

Do you have a link to your project?

Ron

 

Since the project appears to include a processor board of some type, to interface with a number of hard drives, my first question is if the required power supply to convert mains power to the lower RC voltages would be part of the package, is that 3 pin connector for the DC voltages or for the mains power?? CERTAINLY, interrupting the DC power to a hard drive package WILL CAUSE DATA LOSS! I have read about that happening quite a few times, and that the data was not able to ever be recovered. The details of the form of your version of the project are not clear to me.

If the connection is for DC power, there are MANY suitable MS type reliable connectors available from multiple distributors, while if it is for the AC mains power, I suggest the standard common 3-pin IEC connectors used with power cords for most computers and much other equipment.

 

Really a 10 amp buck converter is quite a large step down. My choice would be just run with an ATX PSU. They are common and inexpensive. Rough estimate is a typical HDD requires about 25 watts at spin up and then only about 8 watts maximum while running. How many drives are you planning to run? How much current would your buck converter have to deliver allowing for about a 20% overhead?



Do you have a link to your project?

Ron

Here it is. The ATX psu is not an option in this case. I plan on running 2 HDDs for now but I want the option to populate the remaining 2 bays at some point.
https://makerworld.com/en/models/13...-enclosure-for-lenovo-m920q#profileId-1451077

 

Since the project appears to include a processor board of some type, to interface with a number of hard drives, my first question is if the required power supply to convert mains power to the lower RC voltages would be part of the package, is that 3 pin connector for the DC voltages or for the mains power?? CERTAINLY, interrupting the DC power to a hard drive package WILL CAUSE DATA LOSS! I have read about that happening quite a few times, and that the data was not able to ever be recovered. The details of the form of your version of the project are not clear to me.

If the connection is for DC power, there are MANY suitable MS type reliable connectors available from multiple distributors, while if it is for the AC mains power, I suggest the standard common 3-pin IEC connectors used with power cords for most computers and much other equipment.

The HP mini pc has a 35w TDP cpu and the stock PSU is 19.5v 3.33A, so 65W. That's the reason I wanted to go with another HP PSU with the same voltage but higher amperage. In case the link is not working, that would be a 19.5v 10.3A, so 200W. The connection is for the DC power. The stock barrel is 7.4x5mm but I'm willing to cut that and solder whatever connector you recommend since a panel mounted option for that size isn't available. I'll modify the 3d file for the case so I can mount it properly. I'm not planning on disconnecting the power for the HDDs so don't worry about that.
My plan:

HP 200W PSU	-> Panel mounted connector	->Computer via a cable like this
		->12V 10A Step-down converter	->barell jack to 4 x sata power plugs adapter

 

The HP mini pc has a 35w TDP cpu and the stock PSU is 19.5v 3.33A, so 65W. That's the reason I wanted to go with another HP PSU with the same voltage but higher amperage. In case the link is not working, that would be a 19.5v 10.3A, so 200W. The connection is for the DC power. The stock barrel is 7.4x5mm but I'm willing to cut that and solder whatever connector you recommend since a panel mounted option for that size isn't available. I'll modify the 3d file for the case so I can mount it properly. I'm not planning on disconnecting the power for the HDDs so don't worry about that.
My plan:

HP 200W PSU	-> Panel mounted connector	->Computer via a cable like this
		->12V 10A Step-down converter	->barell jack to 4 x sata power plugs adapter

Please understand that the 19.5 volts from the external supply, oor whatever supply you provide, needs to pass thru the internal voltage conversion circuits to supply the 12 volts and the 5 volts for all of those added hard drives.. The problem then is that the internal power conversion circuit components are not ratedto handle that additional current! THAT is where you will have a problem of the original system not being able to power the additional load.

I don't see any simple way around that problem. In fact I don't see how that published project handles it, either. Does it only power one hard drive at a time??? It seems that there are a few details missing in the information that we have.

 

Here it is. The ATX psu is not an option in this case. I plan on running 2 HDDs for now but I want the option to populate the remaining 2 bays at some point.
https://makerworld.com/en/models/13...-enclosure-for-lenovo-m920q#profileId-1451077

Nice NAS box. Mine is an old WD (Western Digital) two drive flavor. All things considered if all you want is 12 volts and starting with 19 volts (common laptop supply) I would just buy a 12 VDC Buck Converter. I am seeing plenty on Amazon. Figure 12 Volts at 10 Amps Max is only a 120 Watt unit.

Ron

 

Please understand that the 19.5 volts from the external supply, oor whatever supply you provide, needs to pass thru the internal voltage conversion circuits to supply the 12 volts and the 5 volts for all of those added hard drives.. The problem then is that the internal power conversion circuit components are not ratedto handle that additional current! THAT is where you will have a problem of the original system not being able to power the additional load.

I don't see any simple way around that problem. In fact I don't see how that published project handles it, either. Does it only power one hard drive at a time??? It seems that there are a few details missing in the information that we have.

He's using a separate 12v 6A power supply for the HDDs. I wanted to power everything from the same PSU but even if that's safe I wonder what are the power loses in stepping down to 12V.

 

Nice NAS box. Mine is an old WD (Western Digital) two drive flavor. All things considered if all you want is 12 volts and starting with 19 volts (common laptop supply) I would just buy a 12 VDC Buck Converter. I am seeing plenty on Amazon. Figure 12 Volts at 10 Amps Max is only a 120 Watt unit.

Ron

I wanted to do it for a while since these pc's are very capable but pretty limited when it comes to storage. Any idea what connector I should use for the panel mounting?

 

I wanted to do it for a while since these pc's are very capable but pretty limited when it comes to storage. Any idea what connector I should use for the panel mounting?

I would just look at DC Power Connectors and choose one which will handle the current. I can share this much. My two drive NAS box runs off a 12 volt wall wort delivering 12 Volts 3 Amps. It used a common DC barrel jack connector. Actually the forum has an article about that. Anyway any DC connector rated for the Voltage/Current you plan to draw plus about a 20% overhead. Don't over think this. Anything like this will do just fine:
Lsgoodcare 5.5 x 2.1 MM 10A DC Power Jack Socket Dc099 30V Threaded Female Mount Connector Adapter with 3.94 Ich 18AWG Cable and DC Barrel Jack Plug Male

Ron