Voltage monitor card

The 9902 voltage monitor unit is capable of monitoring a single supply voltage and provides three alarm trip points.

Two trim pots are provided for each trip point, one determines the point of alarm setting on and the other determines the alarm reset point.

Test points are provided so that the set and reset point levels can be measured with a suitable multimeter.

The alarm points provide high-high volts, low volts and low-low volts that can be typically used to monitor a single voltage such as a battery system. Both 12 and 24 V battery systems can be monitored. Alarm outputs are implemented as a set of changeover relay contacts with one contact set provided for each of the three alarm points. These contacts are available via an onboard connector.

The monitor may be set to either normally energise or de-energise the relays during operation.

It allows for selecting four time-out periods between the alarm trip and relay activation.