mini-box M3-ATX User manual

GND
+
Switch Logic
6
-
24
V
DC
-
DC
ATX PSU
PC
ATX power
Mother
Board
ON/OFF switch
M3
-
ATX
Battery
Ignition SW
-
+
Seri
al
ctlr
8bit MCU
Amplifier
Enable
Reverse and
forward protection
Status LED
M3-ATX
6-24V Intelligent ATX Power Supply
Installation Guide
Version 1.0c
P/N M3-ATX-01
Before you start…
Please take a moment and read this manual before you install the M3-ATX in
your
vehicle. Often times, rushing into installing the unit can result in serious damage
to your M3-ATX board, computer and probably your car’s electrical system.
Always double check the polarity of your wires with a voltmeter.
Avoid using the cigarette plug as a power source, often times the contacts are
not capable of delivering high current to your PC.
Introduction
Thank you for purchasing the M3-ATX power sequencer / vehicle ATX power
supply.
The M3-ATX was designed to work with a wide variety of main boards such as
the VIA mini-ITX motherboards as well as Pentium-M / Celeron or full power
Pentium systems.
M3-ATX Logic Diagram

http://mini-box.com, Embedded PC Solutions
M3-ATX User Guide Page 2
1.2 M3-ATX Connection diagram
Power Input Connectors (right side)
Red Battery + (positeive, un-switched battery)
Black Battery - (negative)
White Ignition (To start connect to Battery +).Do not use in the standard
PSU mode (mode P0)
Power Output Connectors (left side)
Hard drive wire harness (HDD, SATA-HDD, Floppy)
ON/OFF and THUMP wire harness (connects to M3-ATX pin header)
-ON/OFF wire harness (red/back) to connect to motherboard’s ON/OFF pin
headers.
-THUMP (white) to connect to amplifier remote ON/OFF connector.
Wire harness for motherboard
ON/OFF switch and Thump
control (optional
Wire harness for serial
connection.
IMPORTANT: Always use the “Hibernate” feature on your PC, never use
“Standby”.
P Off-delay Hard-off
P0 Standard PSU mode
P1 5sec 1 min
P2 1 min 5 min
P3 30 min 2 hour
P4 custom custom

http://mini-box.com, Embedded PC Solutions
M3-ATX User Guide Page 3
P0: In this mode, the M3-ATX behaves like a regular ATX power supply.
P1: Sends ON pulse to motherboard when ignition is ON for more than 2
seconds, sends OFF pulse to motherboard 5 seconds after ignition is turned
off. Waits another 1 minute and then shuts down 5VSB to conserve battery. In
this mode, the M3-ATX consumes less than 0.5mA. This is our
recommended setting.
P2: Sends ON pulse to motherboard when ignition is ON for more than 2
seconds, sends OFF pulse to motherboard 60 seconds after ignition is turned
off. Waits another 5 minutes and then shuts down 5VSB to conserve battery.
P3: Sends ON pulse to motherboard when ignition is ON for more than 2
seconds, sends OFF pulse to motherboard 30 minutes after ignition is turned
off. Waits another 2 hours and then shuts down 5VSB to conserve battery.
P4: Can be set to any value. Setting can be done via an optional serial cable.
(Default values for P4 are Off-delay=30sec, Hard-off=30sec)
NOTE: To reset to the M3-ATX settings to the factory defaults (in case changes
were made via the serial uplink), simply power off the unit, connect a jumper as
shown and then power back up. The LED light will start to flash rapidly
indicating that the factory defaults were loaded. Don’t forget to
Remove jumper when done!.
Power challenges in a Vehicle PC: One of most difficult tasks of operating a
PC in a vehicle is power consumption while the computer is OFF. Even when
your computer is OFF, it will still consume about 100mA on the 5V rail. When
the computer is in the suspend mode, it will consume even more power,
because the RAM needs to be powered at all times. No matter how big your
battery is, you will eventually drain it if proper actions are not taken.
The M3-ATX is addressing these issues by cutting off the 5VSB rail after a pre-
defined amount of time (see jumper chart, HARDOFF). During the HARDOFF if
the battery level drops below 11.2V for more than one minute, M3-ATX will shut
down and re-activate only when the input voltage is > 12V.
Engine Cranks, under-voltage and over-voltage situations. Another difficult
task is maintaining stable power to your PC. While car batteries are rated at
12V, they actually provide voltages in between 7-11V (engine cranks) or as high
as 80 volts (load dump). Most of the times, your battery will stay at 13.5V (while
car is running) but extra precautions need to take place in order to prevent such
situations. M3-ATX can operate as low as 6V and as high as 24V while
providing strict regulation on all rails along with input voltage clamping and
reverse protection.
Loud amplifier pops when PC starts. If your PC is connected to your car
amplifier, you will hear a loud pop when the computer is first started. The M3-
ATX has an ‘anti-thump’ control that will keep your amp OFF while the PC
starts. Simply connect the white wire from your M3-ATX cable harness to your
amplifier remote control pin.

http://mini-box.com, Embedded PC Solutions
M3-ATX User Guide Page 4
Mode of operation
1) Ignition=OFF. Nothing happens. M3-ATX is waiting for ignition signals.
2) Ignition=ON. M3-ATX waits for 2-3 seconds then turns on the 5Vsb rail. After another second
M3-ATX sends an “ON” signal to the motherboard via the 2 wires connected to the
motherboard’s ON/OFF pins. The motherboard will turn ON and your system should start
booting.
3) Ignition=ON. Your computer will remain ON.
4) Ignition=OFF. M3-ATX waits for “OFFDELAY” in seconds (see jumper chart) and then it turns
the motherboard OFF by sending a signal to the motherboard’s ON/OFF switch. Your
computer should turn off gracefully (shutdown procedure). After shutdown, 5VSB will still be
provided for another “HARDOFF” seconds. In the event where the shutdown process is
longer than “HARDOFF” (Operating System gets frozen, etc), power will be shut down hard,
turning off all power rails. During the HARDOFF procedure, the battery levels will be
constantly monitored to prevent deep discharge situations.
5) M3-ATX will go to step 1, if ignition is tuned ON again.
NOTE. When all config. jumpers are removed, M3-ATX acts as a regular power supply, no ignition timing,
no HARDOFF. M3-ATX will send a gratuitous “ON” pulse to the M/B when power is applied for the first
time. Do not connect the on/off switch if you don’t want your PC to be started automatically.
Troubleshooting
a) Motherboard is not turning ON: Check input cables.Make sure you have a
a well tighten wire harness. Measure the un-switched pin (red). You should see
12V (car on) or 0V (car off). NOTE: In P1, P2, P3 modes if V(In) is < 12V, the
M3-ATX will not start.
b) Motherboard is not turning ON (cont): Ensure total system power
consumption does not exceed the M3-ATX specifications.
c) Motherboard is not turning ON (cont). Make sure that the ON/OFF wire
harness from the M3-ATX is connected to the ON/OFF switch of your M/B.
M3-ATX Characteristics
Minimum Input Operating. voltage 6V
Maximum input Operating voltage 24V (clamping will occur at 25-27V)
Deep-Discharge shutdown threshold 11.2V
Input current limit (fuse protected) 15A
Max Output Power 125 Watts (8-16V, see chart below)
Deep Sleep Current Consumption. < 0.5mA
Storage and operating temperature -55 to +125 degrees Celsius (storage), -40 – 65C
(operating)
MTBF 150,000 hrs @ 50C, 96,000 hrs @65C
Efficiency (Input 9-16V) >94%, all rails combined, 50% load.
Input connectors Faston 0.25” terminal
Output Connector ATX Power 20 pin (Molex P/N 39-01-2200)
*Units starts failing at >125 Celsius. Operating at temperatures above 85C / 185F will drastically reduce
the MTBF.

http://mini-box.com, Embedded PC Solutions
M3-ATX User Guide Page 5
Maximum Power Characteristics
Output Rail Current (Max) Current Peak
(<30 seconds)
Regulation
5V 6A 8A 1.5%
3.3V 6A 8A 1.5%
5VSB 1.5A 2A 1.5%
-12V 0.15A 0.2A 10%
12V 4-6A (see below) 8A (see below) 2%
When operating at <8V or >16V or extreme temperatures, de-rate by 25-50%, ventilation will be required.
12V Rail Output Current (buck/boost converter)
Input (V) 12V out current Input (V) 12V out current
6-8V 4A (6A peak) 11-16V 6A (8A peak)
8-11V 5A (7A peak) 16-24V 4A (7A peak)
Support and warranty: Standard Hardware Warranty 1Year / US, 2 Year EU
Installation support: 30days via email, [e-mail]