DAD FZ10004, Руководство пользователя

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FZ10004
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Safe Operating Area detector (SOAD)
The Safe Operating Area Detector (SOAD) compares output voltage against output current to ensure that
the output transistors are working inside their safe operating area.
The SOAD provides fault monitoring and input to the Current Peak Limiter (CPL). The SOAD has no dedi-
cated indicator, and its operation is revealed only in conjunction with features such as the CPL.
High-impedance warning (open load)
A high-impedance (open load) condition is indicated when an input signal above approximately -29dB is
detected and no functioning loudspeakers are connected to the amplifier. The fault in indicated by a red
Sig/Hi-imp LED. The indicator is green when a valid load is present under the same input signal conditIons.
Since the Hi - impedance detection initially triggers only when the input signal rises above -29dB, it might
cause the indicator to first turn green, and then red, even in situations where no speaker is connected.
Low-impedance protection warning
A low impedance or short circuit fault is detected when current draw is high (Current Peak Limiter ac-
tive) and when, simultaneously, output signal is low (-4dB LED does not illuminate). When this occurs, the
amplifier protects the output stage from damage by muting the output signal and bypassing the circuits.
Indication of this fault is a constant red illumination of the Current Peak
Limiter (CPL) LED on the front panel. The protection will sequence at 6 second intervals to re-measure
conditions. If the low-impedance fault is no longer detected, the amplifier will un-mute.
If the CPL turns constant orange, the output is muted, and the -4dB signal LED is ON, then the amplifier has
gone into maximum current protection. This situation is caused by an excessive input signal and is not due
to a short circuit. Turn down the input signal to avoid or remedy this situation.
Temperature protection
If the temperature becomes too high to continue safe operation, the overheated output channel(s) will be
muted until the temperature returns to an acceptable level.
Fully active temperature protection (with muting) is indicated by a constantly illuminated TEM LED.
Temperature measurements will continue at 6 second intervals. The output will un-mute when the chan-
nel or power supply returns to a safe operating temperature.
Power Average Limiter (PAL )
The Power Average Limiter (PAL) controls the current-drawing relationship between the power supply and
the mains inlet. PAL limits the maximum average power consumption according to the power supply ca-
pabilities, ensuring that the PSU will not overload. In addition, in the larger models that potentially could
pull more current from the mains than the mains fuses are specified to handle (more than 16 A), PAL limits
the amplifier’s maximum current draw to prevent blowing the mains fuse.
Soft - Start
High powered amplifiers with inadequate inrush limiting can pull considerable current from the mains at
turn-on. This can result in tripping of fast acting mains breakers. Such is not the case with amplifiers. The
amplifiers have very low inrush power as the capacitors are charged slowly and in a controlled manner
ensuring that breakers will not trip.