Motherboard - Intel Desktop Board D510MO (embedded):
- integrated (soldered onboard) 1.66 GHz Intel Atom D510 processor (2 cores, 4 threads) with a passive heat sink
- Intel NM10 Express Chipset
- support up to 4 GB DDR2 800 MHz memory
- integrated 1Gb/s Ethernet controller - Realtek RTL8111DL
- integrated video Intel GMA 3150
- integrated audio controller - Realtek ALC662
- integrated legacy I/O controller Winbound W83627TGH-I: two serial ports, one parallel port, PS/2 keyboard and mouse ports
- other interfaces: two SATA 3Gb/s ports, seven USB 2.0 ports
- one PCI slot (in the end, we have installed on it an additional network adapter: Intel PRO/1000 GT)
- one PCI Express Full-Mini Card Slot
- small form factor: Mini-ITX
- low power consumption
- low price
Power Supply - PPQ 1003B:
- 110 W rated power
- quad output (+3.3 V, +5 V, +12 V and -12 V)
- built-in active PFC function
- CE conformity
- switching frequency: 67 kHz
- 100% full load burn-in test with quality engineering test report
- open PCB power supply (without frame)
- short circuit, overload and overvoltage protection
- does not have a built-in voltage supervisor circuit (it is not compatible with TFX12V/SFX12V/ATX12V
standards and this is a big disadvantage when it is used in PC applications)
- the use of a solid state disk (SSD) is recommended. As an alternative option, a SATA model can be used.
Our prototype was built with a Seagate ST250DM000-1BD141 250GB hard disk.
- we have used an old slim aluminium enclosure, initially designated for other not finished project, which was
lying around for many years. We have adapted this case to our purpose. There is room inside for
two 3.5" hard disks. Also this case acts as a heatsink for the hard disks. You can use any case you want:
mini-ITX, ATX-desktop, minitower and so on, new or second hand. You have to find a possibility
to mount the power supply and the motherboard in your case.
Because the power supply and the case used in this project
are non-standard for PC, we have used 12 mm metal hexagonal threaded spacers to mount
all the components inside. The case is vertically positioned for better air circulation.
- there are two fans in our project, first one is used for power supply and second one is used for mainboard.
According to PPQ-1003
data sheet, with natural convection cooling, we can obtain only 70 W on
To obtain 100 W, we need a forced
air cooling of 17 CFM at least. For that,
we have used an ultra-quiet 120 mm fan made by Akasa: AK-183-L2B, 12V DC
voltage rating, with 1400 rpm fan speed and 44.8 CFM airflow (nominal values).
Because is no need for the nominal airflow,
we have decided to supply this fan with a reduced voltage of 5V DC,
which correspond to approx. 600 rpm. The airflow obtained is enough to keep the power supply board and
the heatsink at reasonable temperatures.
In this way, the noise level
created by this fan is also decreased significantly.
The second fan is used to create an air flow for the motherboard (the heat sink of the processor and the RAM modules).
The fan we have chosen is a MagLev ME60151V2-000U-A99 from Sunon (low acoustic noise level,
high reliability, auto restart, dust resistant).
This is a 12 V DC rated fan, but we
have used 5 V DC as power supply for it. The fan acoustic noise level is
also reduced by powering it with a lower voltage.
(This fan can still work even if it is powered with 3.3 V.)
The motherboard has a fan output with PWM capability. According to our tests,
in this particular case, to obtain
a lower acoustic noise level, it is better to use a lower than nominal voltage for the fans
power supply instead of using PWM. The only condition is to test
the fans at these voltages, before using them in PC, to be sure that always start to rotate at power on.
We have performed some temperature measurements (figure 5 and 6, when the ambient temperature was 26°C
and without heavy CPU usage). With fans stopped,
CPU temperature was around 42°C and the power supply temperature
around 57°C (close to the 60°C limit for
this device). With fans running, the temperatures have been decreased to around 35°C for both CPU and
power supply. Figure 7 was taken with fans running and ambient
temperature close to 30°C.