13 Replies Latest reply on Nov 30, 2015 1:27 AM by greenrover1

    Intel NUC on12 volts using DC-to-DC converter for 19 volts?

    73

      I have an application that is very similar to an automotive installation. I need to be able to run the Intel NUC D54250WYB off of a12 volt power source with a separate ignition wire as input reference.  I found a DC USB 200 which is capable of converting 12 volts into the required 19 volts for the NUC given the right jumper settings and the DC USB 200 accommodates the ignition wire as an input reference.  However, I'm having a little trouble figuring out where on the D54250WYB motherboard to plug in the DC USB 200 so that the power on and the time delayed power off feature will work.

       

      I have been reading the NUC technical manual for D54250WYB and it would appear that the Front Panel Header pins 6 or 8 (or both) may be where the DC USB 200 is supposed to interface with the D54250WYB but I'm not sure.   I've ordered the BOX D54250WYK1 but it will be several weeks before it comes in and I'm not even sure that pins 6 / 8 are even available.  

      Intel NUC Front Panel Header.gif

       

      The technical reference for the DC USB 200 states "J8 Soft ON/OFF control for motherboard. Connect this to motherboard ON/OFF pins if you want the motherboard to be controlled by the unit."

      DCDC-USB200 Layout.gif

      I have only a little experience with older motherboards and I don't want to damage my new D54250WYB so I'm hoping someone here on the forum can help me confirm the proper connection point(s) on the board.

       

      The technical reference for the DC USB 200 is attached in case that might be helpful.

       

      Thank you for your time.

        • 1. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
          sylvia_intel

          Hello 73, I would like to confirm you that pins 6 and 8 are available on this NUC, actually they are available on all of them.



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          • 2. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
            73

            Thank you Sylvia.  Any idea if those are the correct pins to use for the on/off signal coming from an automotive power supply such as the DCDC USB 200?

            • 3. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
              sylvia_intel

              Those are the pins we use in our products for ON/OFF, but I will recommend you to verify with the power supply manufacturer.

              • 4. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
                wdpless

                I have a similar project and will be tapping into those same pins. While searching for the jumpers with wires to connect securely I am having trouble finding 2.0mm pitch connectors. Most of what is sold is 2.54mm. Does Intel sell this accessory or do I need to order from china(currently in US). Any help would be appreciated. Thanks.

                • 5. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
                  sylvia_intel

                  Wdpless, we do not sell these connectors. I’m sorry.

                  • 6. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
                    spearson

                    #73,

                     

                    I am not sure why you are going down this path. The Intel(R) NUC D54250WYB can be run using any input voltage in the 12V to 19V range. You do not need to use a DC-DC converter to up the voltage to 19V...

                     

                    ...Scott

                    1 of 1 people found this helpful
                    • 7. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
                      technuc

                      Are the voltage regulators on the 4th gen boards able to handle an unclean 12V that you'd get on a lead-acid car battery? When low, these batteries could hit 11.4V or so and could go up to 14V when charged. I just want to know if the regulators can take 11.4V, even if not "officially" supported.

                      • 8. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
                        73

                        Hi spearson,

                         

                        In automotive applications, the vehicle electrical circuits can experience a number of "transients".  Please see the following white paper from Advantech:  http://www.advantech.com.tw/eservice-applied-computing/newsletters/white%20paper/Power_Challenges_Faced_by_Vehicle_Applications.pdf

                         

                        TypicalAutomotiveTransients.jpg

                         

                        So they say it isn't a good idea to connect sensitive computer electronics directly onto a car battery.  A good DC to DC Power Supply designed for use in automotive applications will buffer the incoming electrical to filter out the typical automotive transients and output a clean stable voltage which will not harm the sensitive computer electronics.

                         

                        Some of the power supplies out there are expensive (think high amperage / high wattage police car power applications).  I bought mine for about $75.00.  It is a small price to pay for peace of mind and stable long-term operations.  I justify the cost in my mind as a form of insurance.

                        • 9. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
                          73

                          Hi technuc,

                           

                          The Intel specifications indicate the NUC runs on "DC Power 12 - 19 V, 65 W".  At a voltage on the low end or even slightly below manufacturer's specification the electronics "might" work but if they do, they have to work harder and they put out more heat due to the inefficiency.  (Not to mention possibly voiding the warranty.)

                           

                          For my application, I would prefer not to "test" the limits of the NUC or risk shortening the life span of the unit.  By using a "buck boost" capable power supply I am able to use any DC source ranging from 6 volts to 34 volts and still get clean, stable output power to the NUC at a single stable voltage the NUC prefers.  (Also... by using an external DC to DC power supply, the heat generated by voltage conversion is kept outside the NUC case where it can be safely dissipated without overheating the NUC board.)

                           

                          The intelligent power supply (DCDC-USB-200) paired with my NUC will also send a shutdown command to the computer if input voltages reach min or max levels I've set inside the power supply.  (Because my DCDC-USB-200 also has a USB port, I'm able to use the NUC to monitor input power and output power as well as script the power supply response to various voltage level changes.)

                           

                          With this setup, I feel pretty good that the computer will be kept isolated from issues that automotive power would normally introduce.  My setup may be slightly overkill, but my tolerance for risk is also quite low in this application.

                           

                          Anyway, hope this helps.

                          • 10. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
                            73

                            Here is what I have learned so far about the Intel NUC D54250WYB Front Panel Header:

                             

                            • Pins 1 and 3 ( Hard Drive LED): Pin 1 is Positive 1.5 volts, Pin 3 is Negative
                            • Pins 2 and 4 ( Power LED):  Pin 2 is Positive 4.8 volts, Pin 4 is Negative
                            • Pins 5 and 7 ( Reset): Pin 7 is Positive 3.27 volts, Pin 5 is Negative
                            • Pins 6 and 8 ( On/Off):  Pin 6 is Positive 3.28 volts, Pin 8 is Negative
                            • Pin 9 (5 Volt):  Pin 9 is Positive 4.8 volts.

                             

                            These figures are as measured by multi-meter on the pins.

                             

                            As I think I understand the way pins 6 and 8 work (and likely pins 5 and 7 as well), the pins are supposed to be shorted to ground in order to send the on/off signal to the motherboard? I could be wrong but I believe the 3.27/3.28 voltages are reference voltages that are measured by the board. When the board senses current flow on pin 6 (or pin 7) then the board triggers an event that is captured by software which then tells the computer to turn on or off depending on the current state ("On" if computer is off, "Off" if computer is on).

                             

                            Alternatively, it could be that the negative pin 8 is being measured for voltage - causing the trigger when shorted to pin 6.  I'm not real clear on how it works.  What I do know is that the DCDC-USB-200 when activating the on/off switch is shunting the two pins to ground when it fires an "on/off" command.

                             

                            I'm guessing a little here as there is very little if any documentation of how this works that I have been able to find so far and certainly no information specific to this board. It would be great if Intel could confirm for us how this works for D54250WYB?

                            • 11. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
                              73

                              Hi wdpless,

                               

                              I had the same trouble.  You might find it easier to purchase the Schmartboard jumpers from Radio Shack for about $7. They work pretty well with the pins on the NUC.

                               

                                   Schmartboard 5" Male/Female Jumpers (10) with Headers (40)

                                   Model: 920-0022-01  | Catalog #: 276-156

                               

                              Link:

                                   http://www.radioshack.com/product/index.jsp?productId=12825863&clickid=prod_cshttp://www.radioshack.com/product/index.jsp?productId=12825863&clickid=prod_cs

                               

                              I was able to find them at my local store.

                               

                              Hope this helps.

                              • 12. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
                                spearson

                                #73,

                                 

                                I am not saying that you don't need to do something to handle transients; I am simply saying that there is no absolute need (for this particular NUC anyway) to up-convert to 19V. Pick the output voltage (12V-19V) that is the least costly. This could be what you've chosen or maybe you want to look again (if not too late). Frankly, I don't think you are being too conservative. As Andy Grove said, 'Only the paranoid survive'...

                                 

                                ...Scott

                                • 13. Re: Intel NUC on12 volts using DC-to-DC converter for 19 volts?
                                  greenrover1

                                  Looking at the spec on this DC-DC converter and I am concerned that they have a low voltage shutdown at 11.4VDC, not a good value for deep cycling batteries as in my case I would lose my NUC and all of the functionality it provides, some critical, at roughly 60% remaining state of charge. Not good. As for pins 6 and 8, this is just a logic low that requires a momentary short to energize the NUC and a longer input to shutdown. I have designed much of my control logic around this simple fact. The DC-DC converter is nice and offers a lot of protection for the NUC however it is quite expensive and the additional protection could be effected with a few simple discrete components or modules for filtering and surge suppression. My power supply thankfully is massive in capacity and provides extremely clean straight line DC as observed on a 60MHZ scope under all source/sink conditions, some of my power control logic deals with a condition where deep cycles might be called upon to start a marine diesel engine normally isolated from the starting battery system and where high surge currents and electrical noise from mechanical energy might actually be an issue, in this case DC power to the NUC is opened for complete protection and self restoring post off normal start logic conditions. They can deal with a restart on the NUC which is less than 35 seconds for W8.1 Embedded Pro!

                                   

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