Coda LINUS12C - Protection and Fan Systems

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LINUS12C 4. OPERATION
4.2 Power amp protection
4.2.1 DC protection
Each output of the power amp is constantly monitored for persistent DC voltage levels. If the 10 V threshold voltage is
exceeded at any of the outputs, the SMPS will be automatically switched o to prevent further damage from overload to
the power amplier and speakers. In this case, the system restarts and tries to readjust the DC parameters. If this does not
succeed after the third run, it switches to a permanent error. A DC issue can be located in the output stage, the driver stage,
or at the input of the amplier.
4.3 Mains protection
4.3.1 Inrush current limitation
Within one second of the LINUS12C ampliers being connected to the mains, the inrush current limiter will charge the
primary capacitors in a controlled way, limiting the maximum mains current during startup.
4.3.2 Mains overvoltage detection
There is a overvoltage protection in the mains input. If the mains input voltage exceeds 270 V, the main power supply
remains switched o and a high, loud buzzing tone sounds from the device as a warning.
4.4 Main SMPS protection
4.4.1 Overcurrent protection
The main SMPS (Switched Mode Power Supply) transformer current of your LINUS12C amplier is continuously monitored.
If overcurrent occurs, the main SMPS immediately stops working. Should there be an internal failure, this feature prevents
other parts from being damaged.
4.4.2 Overload protection
The output stage is permanently monitored for possible overload situations. There are varying limiting levels of the
look-forward overload protection depending on connected output load. These limits will be set automatically from a load
measurement on each output channel. This improves reliability without degrading sound quality when driving complex
loads. In case of extremely high output levels with heavily clipped output signals and low loudspeaker impedances < 2.5
Ω, this additional protection will reduce the amplier stage output power very quickly. If activated, this indicates that the
amplier is running close to its absolute maximum power capacity and the limit LEDs on the front panel are ashing.
In normal operation (no clipping or only slight clipping) this protection should never be activated.
4.4.3 Thermal protection
The temperature of the main SMPS transformer of your LINUS12C amplier is permanently monitored. If the temperature
exceeds 70° C/158° F, a thermo limiter will act on the total system power and avoid a SMPS shutdown.
4.5 Fans
The fans mounted in your LINUS12C amplier operate permanently, but as long as the temperature remains below 40°C
/104°F, they will run at their slowest speed. The highest detected temperature from the heatsinks of each channel and
SMPS transfortmer controls the speed of the fans. Above 40°C/104°F the speed is increased until it reaches its maximum
value.