The Sentry UL range provides automatic, current limited and thyristor
controlled charging of vented lead acid or NiCd batteries. The units may
be used in a wide range of industrial charging applications, including
standby engines, pumps and generators.
The charger uses an open frame construction, designed for surface
mounting in an enclosed panel. Each unit consists of a transformer, rectifier
and control circuit. The control circuit ensures that the charger maintains
a battery voltage at the pre-calibrated float level, while supplying
any additional load current up to the specified maximum.
When used as a float charger, the unit is designed to give a constant current
output while battery voltage is below a ‘knee point’ (approx. 13V on a
12V LA). Above the knee-point, as the battery approaches its float voltage,
the Sentry output current ramps down. This multi-stage charge
regime gives an optimum combination of fast charge rate, followed by
float charge without overcharging.
