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We have several models of the
DC/DC auto UPS control module. This one works in 12 volt systems, has a
throughput of 5 amps and has the ability to drive LEDs or relays to indicate
the status of the UPS.
This is a microprocessor
controlled uninterruptible power supply control module. You can connect the
module to the car's electrical bus and it will charge an external 12 volt lead
acid battery of your choice. Your equipment, for example, a small computer,
video recorder, or a car alarm, is connected to the module. This equipment runs
off the automobile's electrical bus until the voltage from the car drops below
a preset voltage, the "N" voltage (from 13.1 to 11.9 volts, depending on your
needs). Then the external battery takes over. When the external battery drops
below the "P" preset voltage (Between 10 volts and 3 volts depending on your
requirements) the power is cut off to either prevent damage to the external
battery or to run your equipment as long as possible.
These controllers can charge an auxiliary battery from the car's
auxiliary battery is isolated from the car's electrical system so that it will
only operate the equipment attached to the load terminals of the controller.
The load terminals power
your equipment from either the car or the auxiliary battery, acting as a
battery backup (BBU). The switch position depends on the voltage levels of the
two inputs. This allows your equipment to be powered from the car when car
power is available.
The DC UPS controller
protects the auxiliary battery from being over-discharged.
The control set-points of the DC UPS controller can be set so that
the equipment switches to auxiliary power when the car is shut off.
The setpoints can also be
set so the the crossover voltage is lower, say 12.0 volts. This allows the load
to run off the car's battery but cut off while the car's starting battery still
has enough power to safely start the engine.
One of the most popular applications is to run a small auxiliary
battery that kicks in while the car is starting to prevent equipment drop-outs
when the car's voltage sags.
|Max Charge Current
||60 to 120 mA (see graph below)
|Charging can occur with input
||10V to 15V (this range can be adjusted
during manufacture, usually we set it to come on at 13V input, and to stop
charging when the main battery drops to 12.4V. This allows charging when the
car's engine is turned off.)
|Maximum pass-through current
|| 5 amps
|Maximum pass-through wattage
||60 watts continuous
|Type of battery charged
||Lead acid, VRLA, SLA, etc.
|Nominal Battery Voltage
|| 12 Volts
||0.8 to 17+ Amp-Hours
|Size of module
|External battery connects when the input
voltage to the module drops below
||13.1 to 11.9 volts, see suffixes
|External battery is disconnected from the
load when the external battery's voltage drops below
||10 to 8 volts, see suffixes
|The available custom setpoints are Main
On, Main Off, Charger On, Charger Off, Aux On, Aux Off
document describes how to engineer and specify the 6 custom setpoints if
||Minimum ambient temperature
-10°C (-40°C available upon request)
Maximum ambient temperature of
||0.187 x 0.032 quick disconnect
terminals also known as quick disconnect or Faston terminal
||The connector on the UPS module
is a MOLEX 43650-0316. The customer supplied mating connector shell is a MOLEX
# 43645-0300. You also need three socket contacts to insert into the shell.
These are MOLEX # 43030-0009.
||6 spade terminals clearly
3 Ground terminals
External battery positive
Car battery positive
||PIN 1. Negative side of the MAIN
LED. This pin will be low when load is being powered from the main input.
Maximum sink current is 30mA.
PIN 2. Positive supply for the LEDs. Nominal
output 12VDC. Do not draw more than 30mA from this pin. Current limiting
resistors will be needed in series with the LEDs.
PIN 3. Negative side of
the STANDBY LED. This pin will be low when load is being powered from the
standby input. Maximum sink current is 30mA.
||3 oz, 87 grams
||See drawing below
|| 12V to 12V DC UPS User's Manual
|Theory of operation
5A DC-UPS Theory of Operation
|Country of Origin
||Made in USA, NAFTA eligible
|| See the
shopping cart below
The PST-DC-UPS-1212 can be ordered with a range of "N"
and "P" values, as explained in the following table.
**(For example PST-DC-UPS-1212-N13.1-P10 would be a module
which disconnects from the car battery when the car voltage falls lower than
13.1 volts and turns the auxiliary battery off when it falls to 10
||Voltage at which car battery is cut of
from the load
||Voltage at which auxiliary battery is cut
off from the load
|N13.1 (most common
||13.1 ±0.2 volts
||Load is disconnected from the car electrical bus when the
ignition is switched off
||12.9 ±0.2 volts
||12.8 ±0.2 volts
||12.7 ±0.2 volts
||12.6 ±0.2 volts
||12.0 ±0.2 volts
||11.9 +0.1 -0 volts
||Allows the load to be powered by the car battery most of
the time but still start the car (barely).
||Tell us what you need, the range is between 13.1 volts and
11.9 volts. The tolerance is ±6 mV with 2% accuracy
|P10 (most common choice)
||When deep cycling of the auxiliary battery is desired.
||When longest possible system operation is desired
regardless of loss of auxiliary battery cycle life.
||Tell us what you need, the range is between 7.5 to 14 volts
The tolerance is ±6 mV with 2% accuracies
Hook up diagram:
||Price for quantity 1-49
||Price for quantity 50-99
|| Quantity 500+
|In-line fuse kit, consists of 2 in-line automotive spade
fuse holders for the battery+ and load+ lines. Includes 7.5 amp fuses.
current depends on both the car voltage and the state of charge of the battery.
When the car is running the blue curve applies.
1. Q: My application needs more pass-through current, what can I
A: We have developed a new module with
power up to 120 watts. Click here for details .
2. Q: When the
module turns off because both batteries are below their setpoints when does the
module turn back on?
A: The module turns back on only when the car's voltage
is restored to the proper charge voltage. A new auxiliary battery won't turn
the module back on.
3. Q: What do you have for 24 volt systems?
Consider the 24 volt version of the 10 Amp backup
module which will use 24 volt auxiliary batteries in a 24 volt vehicle.