The Emergency Relay/Charger is a device for assuring immediate back-up power to communications equipment in the event AC power is temporarily lost to the power supply or the supply fails. In addition it will allow the power supply to act as a ?trickle? battery charger without any additional modification.

When loss of DC voltage is sensed by the ERC, it employs a fast-acting S.P.D.T. relay to automatically switch the equipment?s DC input over to a standby battery to allow continued operation. When the power supply is returned to service, the ERC disengages the battery and puts the supply back on line to provide DC voltage. While the power supply is operating normally, a small portion of the output current is directed to the battery to trickle-charge and maintain it at full voltage.( Note: Battery float voltage will be maintained at .7 volts lower than power supply voltage)

Note: If the power supply is down for an extended period, the back-up battery may become significantly discharged while powering the radio. When the supply returns to service, the trickle charge rate of the ERC may be insufficient to restore the battery to full charge in a timely manner. In the event this occurs, a supplemental charger may be necessary to bring the battery to full charge.