Chapter 3: Protection; Turn-On/Turn-Off Muting; Short Circuit Protection; Thermal Protection - Outline TFive User Manual

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3 Protection

3.1 Turn-On/Turn-Off muting

For about four seconds after turn-on, and immediately at turn-off, the amplifier outputs are muted.

3.2 Short circuit protection

A short circuit protection system safeguards the amplifier's output transistors under short circuits and other stressful loads.
It is completely inaudible when inactive. In case of short circuit, the red LED will be light-up and writing "PROT" appears in
the first line of the display(see Par. 2.2 for a detailed description). The amplifier will reset himself 5 times every 2 seconds.
Once 50 resets have been performed and the fault still exisst on the output, the unit sets into steady protection mode. Turn
ON/OFF cycle is needed to restart the unit.

3.3 Thermal protection

A T series amplifier uses a continuously variable speed fan to assist cooling (the fan speed changes in response to the
amplifier's cooling needs). If the heat sink temperature reaches approximately 80°C, the yellow LED starts to flashing. If the
temperature is more then 85°C the thermal sensing circuitry will mute each power section channels, the LED will light
permanently and the power supply will be cut off. Once the heatsink has cooled down, the amplifier will automatically reset
and the LED will be go out. It is possible to reduce the temperature by reducing the output power.

3.4 DC fault protection

If DC or excessive subsonic energy appears at a channel output, an instantaneous protection circuit will cut off the power
supply for both channels. Power supply shutdown is used instead of speaker relays, thereby improving the damping factor
and reliability of the amplifiers.

3.5 Input/Output protection

An ultrasonic network decouples RF from the outputs and keeps the amplifier stable with reactive loads.
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