131219 PRODUCT MANUAL PCM-PS402-512 10
System
The PCM-PS402-512 is a high effi ciency power supply module with a wide input range of 10 - 32 Volts DC. The DC/
DC converters include a built in battery charger and uninterruptible power supply (UPS) controller. It provides power to
a single board computer (SBC) from a wind turbine, solar panel, or other DC source. It can source power from either
the input power connector or from an external battery. The source with the highest available power will automatically be
selected. LEDs provide visual indicators for DC input, battery, fuse, and charge status.
Theory of Operation
The PCM-PS402-512 uses multiphase switch-mode power controllers and low resistance MOSFETs to convert an input
voltage to three regulated outputs. Input voltage can range from 10 to 32VDC and outputs include 5V at up to 10A, 12V at
up to 1A, and -12V at up to 800mA. The combined output power for the three rails must not exceed 50W, with
a maximum
of 12W available from the combination +12V and -12V. High overall conversion effi ciency of 80% to 92% is achieved with
the multiphase SMPS (switch-mode power supply) architecture across all input and load variations. Because of the high
conversion effi ciency, the supply will work across the industrial -40°C to +85°C ambient temperature range.
There is a 10 - 32 VDC input and a 6 - 12V battery connection on the PS402 products. The DC inputs can connect
renewable sources such as wind turbines and solar panels or an appropriately rated external DC supply. The battery
input can connect a 6 - 12V Lead Acid, Li-Ion/Polymer, LiFePO, and SLA battery to the system. Should the input drop
below 9 VDC the supply switches to an external battery input and continues to provide uninterrupted power. When the
external DC input is restored, the supply switches back and begins re-charging the battery. The UPS feature provides a
fast switchover free of oscillations between the two external sources and battery. Switching is accomplished in <500 nS
and hysteresis prevents oscillation. Care must be taken to select sources and batteries with suffi cient power to drive the
intended loads.
The PS402 product line also charges a battery or battery pack. The battery charger employs a constant current/constant
voltage (CC/CV) charging characteristic and is capable of charging a variety of different battery chemistries. The charger
fl oat voltage and charge termination schemes are user programmable to allow batteries as low as 6V and as high as 12V
to be used. The battery charger is a 2A charger that features maximum power point tracking (MPPT) and can servo the
output current based on a preset maximum power point voltage to increase charging effi ciency. The charger has built in
state of charge (SOC), bad battery detection, preconditioning, and end of charge (EOC) features. LEDs provide DC input,
battery and charge status. The controller will charge the battery until either the charge current drops below 200 mA or
a user confi gured EOC time limit is exceeded. The user must select external sources and batteries capable of providing
adequate power to their system.