Campbell Scientific PS150/CH150 12 V Charging Regulators - Manual (Page 9)

PS150/CH150 12 V Charging Regulators
1. Introduction
The PS150 is a 12 Vdc power supply that includes a rechargeable 7 Ah valve-
regulated lead-acid (VRLA) battery and charging regulator. The CH150 is a
charging regulator for an external rechargeable 12 V VRLA battery such as the
BP12 or BP24 offered by Campbell Scientific. Charging power for these
charging regulators is typically supplied by an unregulated solar panel, AC/AC
transformer, or AC/DC converter.
The PS150/CH150 are smart chargers that provide charging with temperature
compensation for optimal charging and battery life. A maximum power point
tracking algorithm is incorporated for solar inputs to maximize available solar
charging resources.
The PS150/CH150 are compatible with the A100 null-modem adapter and the
A105 adapter for additional 12 V output terminals. The A100 Null Modem
Adapter connects and powers two Campbell Scientific peripherals via two CS
I/O 9-pin connectors configured as a null modem. This is useful in linking
different communications technologies; e.g., telephone to radio, at sites that do
not have a datalogger. The A105 adapter may be used to provide additional 12
V and ground terminals where the power supply is used to power several
devices.
The PS150/CH150 charging regulators are termed series regulators, because
the regulators are placed in series between the charging source and the load.
As batteries become closer to fully charged, series regulators reduce the current
drawn from the charging source, to where the charging source may be
completely unloaded if full-charge is reached. While this unloading of the
charging source is acceptable for solar panels, AC/AC transformers and
AC/DC converters, it is undesirable for wind turbines because of the resulting
free spinning when unloaded. Consequently, series charging regulators,
including the PS150/CH150, should not be used to regulate the output of wind
turbines without the inclusion of a way to load the turbine when the batteries
require little or no charging current.
The PS150/CH150 chargers have several safety features intended to protect the
charging source, battery, charger, and load devices. Both the SOLAR – G and
CHARGE – CHARGE input terminals incorporate hardware current limits and
polarity reversal protection. There is a 5 A fuse in series with the CHARGE –
CHARGE inputs in the event of a catastrophic AC/AC or AC/DC charging
source failure. There is a 4.7 A solid-state breaker in series with the 12 V
output terminals of the charger in the event of an output load fault. The
PS150/CH150 incorporate battery reversal protection, which is catastrophic for
most chargers. ESD and surge protection are incorporated on all inputs and
outputs of the PS150/CH150.
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