The Battery DC-Voltage is established using special hi-frequency transformers. Voltage is transformed up to 500 VDC. An Actel-microprocessor is controlling the IGBT-bridge to generate a quartz driven sinus form of the output Voltage. The reactance coil and the 2 step filter will smoothen the sinus form of the output tension. All internal control signals are transmitted by opto-couplers. To reach the highest safety level, ultra sine inverters offer a 100 % separation between Battery circuit and output.
In the event of a complete short circuit and after a time laps of ca. 7 sec. the inverter will shut it’s self down. If a very big current draw is detected at the output, the inverter goes (if necessary) over to the current-limitation. This allows the start up of a very much bigger power consumer above the nomination value of the inverter.
The inverter is protected against wrong polarity of the battery power. If this wrong polarity lasts only for a short moment, the inverter remains ok. If this wrong polarity lasts for a longer period, the high current fuse will blow and the fuse must be replaced in our workshop. With the experience we have had the inverter shows mainly a normal function after this repair.
The Stand-by circuit recognizes a user from ca. 2 Watt on and the inverter is switched on. Smaller user e.g. chargers for Handy need either the connection of a bigger user or the inverter must be configured to "Continuous mode" (by the switch behind the round opening in the front of the inverter). After disconnection during Stand-by mode, the inverter switches back into the current saving mode after a laps of time of ca. 45 sec. This is shown by the blinking of the LED in the front of the inverter every 7 sec.
The IBS Inverters are equipped with an intelligent monitoring of over- and undervoltage. Up to the power class of the IBS inverters the under voltage value for switching off are between 10.5 V and 11.5 Volt. The standby mode happens with a time delay. Therefore the proper start of IBS inverters connected to bigger users or using smaller batteries or partly discharged batteries (as long they can deliver some current) is possible without switching off the inverter. To prevent the stepping-up of the two circuits for high discharging of the battery and for switching-in are strongly damped. After a high discharging disconnection, the voltage of the battery must recover ca. to 12 Volt for switching on the inverter properly. An over voltage of more than 15.5 Volt will automatically disconnect the inverter. The disconnection of the inverter by over- or under voltage is displayed by the red LED (Stand-by).
By overcharge the inverter shuts down (after ca. 7 sec.) and the inverter is restarting again after ca. 7 sec. In situations of extreme charge or in conditions of high temperature the fan will start to run (exception: US30/300 Watt which is designed to work without fan). If temperature of the heat sink rises to 80 °C a safety cut out takes place (red LED Stand-by is lit). After the cooling off of the heat sink to ca. 40 °C the inverter switches on automatically. (Time for this is dependent to circumstances of cooling longer than 30 min.)