mini-box M2-ATX Installation Manual page 3

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allowing your operating system to fully come up. This will prevent disk drive
corruption or systems that remain hung in the ON position. After the first 60
seconds of system operation, the AutoLatch feature will be removed and
system will shut down at as governed by the "Off-delay" setting.
P0: In this mode, the M2-ATX behaves like a regular ATX power supply. If J6 is
connected to the motherboard, M2-ATX will also send a gratuitous "ON pulse"
to the motherboard right after power is first applied. If IGNITION is connected
to the battery, the unit will shut down if battery is < 11.2V. This is to protect
the battery from over-discharging. If Ignition is not hooked up, M2-ATX will
operate from as low as 6V. For more information, please consult the "UPS
mode" documentation on the product page.
P1 (recommended): Sends ON pulse to motherboard when ignition is ON for
more than 5 seconds, sends OFF pulse to motherboard 5 seconds after
ignition is turned off. Waits another 60 seconds and then shuts down 5VSB to
conserve battery. In this mode, the M2-ATX consumes less than 0.5mA. This
is our recommended setting.
1.2 Power challenges in a Vehicle PC
The 5V Standby Problem: 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 or in Suspend, it will still consume about 50-150mA on the
5VSB rail. No matter how big your battery is, you will eventually drain it if proper
actions are not taken.
The M2-ATX is addressing these issues by cutting off the 5VSB rail after a pre-
defined amount of time (see jumper chart, HARDOFF). When 5VSB is always
active (HARDOFF=Never), M2-ATX constantly monitors the battery levels.
When battery level drops below 11V for more than one minute, M2-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 3.3V, 5V, 12V and -12V power to your PC. While car
batteries are rated at 12V, they actually provide voltages in between 7-16V
(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. M2-ATX can operate as low as
6V and as high as 28V 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 M2-
ATX has an 'anti-thump' control that will keep your amp OFF while the PC
starts. Simply connect J6 to your amplifier remote control pins to activate the
'anti-thump' feature.
2.0 Mode of operation
1) Ignition=OFF. Nothing happens. M2-ATX is waiting for ignition signals.
2) Ignition=ON. M2-ATX waits for few seconds then turns on the 5VSB rail. After another
second M2-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
M2-ATX User Guide Page 3