mini-box M2-ATX Installation Manual

GND

+

Switch Logic 6-30V DC-DC

ATX PSU

PC ATX

power

MotherBoard
ON/OFF switch

M1-

Battery

Ignition

-SW +

LED

8bit MCU

Amplifier
Enable

Reverse and

forward protection

Optional On/OFF switch

M2-ATX

6-24V Intelligent Automotive ATX Power Supply

Installation Guide

Version 1.0

P/N M2-ATX-01

Before you start…

Please take a moment and read this manual before you install the M2-ATX in your
vehicle. Often times, rushing into installing the unit can result in serious damage
to your M2-ATX board, computer and probably your car’s electrical system.

The M2-ATX board has several wires that need to be installed in various places.
When installing, 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.

1.0 Introduction

Thank you for purchasing the M2-ATX power sequencer / vehicle ATX power supply.

The M2-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 P4 systems.

1.1 M2-ATX Logic Diagram

http://mini-box.com, Cool Embedded PCs

1.2 M2-ATX Connection diagram

M2-ATX, top view

Power Input Connectors
J1 Battery + (un-switched battery, positive)
J3 Ignition (switched battery, positive. Can test by connecting it to Battery +)
J4 Battery - (negative)

Controls and Settings
J6 Controls amplifier via remote ON/OFF. Left pin is RMT, Right pin is GND
J8 To motherboard ON/OFF switch
J10 User jumper settings (A,B,C,D)
J9 To external ON/OFF switch (optional, J8 is in parallel with J9)

Power Output Connectors
J2 Optional P4-12V power
J7 ATX power connector (to motherboard)
J5 To LED (optional)

NOTE: “If HARDOFF is set to “never”, M2-ATX will automatically
shut down when battery voltage is below 11.2V for more than 1
minute in order to prevent ‘deep discharge’ situations.

Mode “0” is regular ATX power supply mode, no power sequencing
provided, can be used for non vehicle applications.

Avoid using HARDOFF = Never, can severely discharge your
battery if PC. Suggested modes are: 1, 2, and 4.

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, it will
still consume about 100mA on the 5V rail. All power supplies provide 5VSB (5V standby)
so that the motherboard can issue at least a PSON signal. 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, it will eventually drain your battery in a matter of days.

M2-ATX User Guide Page 2