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The DP024 is a fully compliant ATX power supply designed to power a low power system from a single 24V power source of a vehicle.
The DP024 power supply has an MCU that controls and monitors various functions of the power supply operation. Also, it realizes
voltages monitoring, temperature monitoring and communication via COM-port with computer. As well the MCU realizes a WatchDog timer
to supervise the computer. A LED indicator continually reports the power system status and health. Also, you can use it for troubleshooting.
Notwithstanding the fact that the DP024 can operate without active cooling it realizes a hardware-firmware device for a temperature-based
automatic-fanspeed control of two fans. Reducing of the fan speed as the temperature drops minimizes the system acoustic noise,
prolongs fans service life period, diminishes power consuption. The use of two fans that has been controlled by DP024 allows to build
a system with redundant cooling facilities and allows to design fault-tolerant system with long-life performance. For operating at low
temperature the DP024 can act as thermostat with heating.
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There are four main operating modes of the DP024 - Deep Sleep, Sleep, Standby, Power On.
The DP024 has user selectable MCU driven timing settings, allowing you to choose various
ignition/shutdown vehicle computer timing schemes (settings). These settings are user
adjusted and saved in EEPROM.
One of most difficult tasks of operating a computer in a vehicle is power consumption while
the computer is OFF. Even if your computer is totally OFF (standby mode), a computer
will still consume a few hundred milliwatts, needed to monitor computer ON/OFF status.
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/sleep mode, it will consume even more power,
because the RAM needs to be powered at all times. The power consumption in the suspend mode
is few Watts. No matter how big your car battery is, it will eventually drain your vehicle
battery in a matter of days. The DP024 is addressing these issues by cutting off the 5VSB rail
after a pre-defined amount of time (timing settings). The DP024 monitors battery voltage to
protect against deep discharge. When battery level drops below predefined value for more than
predefined time, the DP024 will shut down and re-activate only when the input voltage is >
predefined value.
Of course, there is a traditional PC PSU mode setting with no ignition control (shutdown logic
bypassed) and it can be used in non-vehicle computer applications.
Operating as a thermostat with heating at temperature lower than 0ºC as well as automatic-fanspeed
control of two fans for reliable cooling at high temperature together with teperature control from
two sensors (remote and internal) allow to design fault-tolerant system with long-life performance.
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| Features |
- Wide input range (19-35V)
- Suitable for automotive applications
- Suitable for battery powered applications
- Complete with start-up/shut-down control (saved in EEPROM)
- Compatible with most ITX boards equipped with a 20pin ATX connector
- Possibility to control by two standard 12V cooling fans (3-pin)
- Realizes a thermostat by driving heater at temperature lower than 0ºC
- Silent operation (fanless)
- Temperature control
- Low heat dissipation (efficiency over 85%)
- Open frame, chassis mountable, measurements: 36x170x26
- Connection via COM-port with computer
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| Specification |
- Output power 90W.
- Input voltage : +19~35VDC (nominal - 26V).
- Output : +12V 0~4A | +5V 0~6A | +3,3V 0~6A | -12V 0~0,1A | +5Vsb 0~6A
(at 26V input)
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NOTICE: Total current on 5Vsb and 5V rails does not exceed 6A. Do not connect a Car Battery Charger directly to the DP024.
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Connection to car electrical system |
The DP024 should be attached and tuned by specialized personnel only after familiarizing with
User manual
Please take a moment and read this manual before you install the DP024 in your vehicle.
Often rushing into installing the unit can result in serious damage to your DP024 converter,
computer and probably your car electrical system. The DP024 has several wires that need
to be installed in various places. When installing, always double check the polarity of
your wires with a voltmeter. NEVER use the cigarette plug as a power source; often the
contacts are not capable of delivering high current to your PC.
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Connect the IGNITION+ to the switched +24 Volt supply wire (“ignition” circuit or fuse box).
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Connect GND and POWER circuits with heavy gauge wire directly to the automotive batteries (+) and (–) terminals.
GND may also be connected with heavy gauge wire to the Chassis if desired.
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Apply 24 Volts to IGNITION+ by turning on the ignition or by flipping a switch and you’re ready to go!
NOTICE! It is desirable to connect the DP024 to 24V car electrical system via surge protector (shown
hatched). This device should suppress glitches above 40V that sometimes occur in 24V car electrical system
and should provide conducted immunity according to ISO7637.
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The DP024 can be tested in the lab before being installed into the vehicle. Certain details need to be
noted for proper bench testing. When connecting bench power use between 24 to 32 Volts DC to POWER (+)
and GND (BATTERY) (-) terminals for best results. The best way to do successful bench testing is to use
an adequately sized 24V battery. Bringing in the battery from the car or using an extra one that has
at least a 10-AmpHour capacity will be sufficient in most cases. To aid in bench testing, do not connect
IGNITION+ anywhere. The DP024 will operate as “dumb PSU” with button “POWER” control.
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Connection to the battery that is charged by AC-DC charger;
Creation of high efficiency uninterruptable power supply (UPS)
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Connect GND and POWER circuits with heavy gauge wire directly to the batteries (+) and (–) terminals and
charger as shown on figure below. Charger should have rectangular output characteristic (constant current
with voltage limit) that has been complied with battery parameters. This compliance is quite difficult
and is beyond the scope of this application note and will not be discussed here.
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CAUTION! Wrong type of battery and charger maybe the cause of low efficiency this circuit and even
maybe the cause of demage of battery and charger.
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