Camco 32 dB - Manual (Page 20)

4 OPERA
TION
USER MANUAL
VORTEX 6, 4, 2.6 and 200V P.19
4.3.4 Speaker Protect Limiter
Whenever the SOA protection of the power amp switches back the current rail
there could be a small clipping at the output; but the microprocessor is also
triggered by this protection and will reduce the signal level immediately to
minimise the effect.
The user can decide either to use Speaker Protect or not. If you use this amp
for low frequencies (bass / Sub bass) and you want to squeeze the absolute
maximum out of it, Speaker Protect can be switched off. For all other appli-
cations (e.g. Full Range) it’s recommended to keep Speaker Protect switched
on.
4.3.5 DC Protection
Each output of the power amp is constantly monitored for persistent DC voltage
levels. If the 3 V threshold voltage is exceeded at any of the outputs, the main
SMPS will shut down and the channel will be automatically switched off. The
microprocessor performs a sophisticated strategy to locate the cause of the
malfunction. DC can be located in the output stage, driver stage or at the input
of the amplifi er.
Output Stage
When a DC voltage is located at an output stage, the main SMPS remains
switched off. The On LEDs will show a fl ash sequence corresponding to this
malfunction. (See 6 Troubleshooting)
Driver Stage
When a DC voltage is located at the driver stage only the defective channel’s
output stage and the DCA are muted. The other channel continues to work.
The On LED of the defective channel will indicate the malfunction by starting
the relevant fl ash sequence. (See 6 Troubleshooting)
Amplifi er Input
When DC is located at the input stage only the DCA of the affected channel
is muted. The other channel continues to operate normally. If the DC signal
at the input vanishes, the microprocessor will de-mute the affected channel
and the amplifi er will work as usual again.
4.3.6 DC Servo
To prevent DC Offset at the speaker output the VORTEX is fi tted with two DC
Servos. (Hence there are no capacitors in the signal path!)
4.3.7 Over Current Protection
The output stage is permanently monitored for possible current surges. There
are two limiting levels of over current depending on output voltage. These limits
will be set automatically. This improves reliability without degrading sound
quality when driving complex loads.
4.3.8 Thermal Protection
The microprocessor uses several sensors in the amp in order to ascertain tem-
perature data. If the microprocessor detects a temperature of more than 85 °C
at the heat sinks, the input signal on that channel is reduced. If the temperature
exceeds 100 °C, the main SMPS is switched off.
The On LED of the overheated channel will start a blinking-sequence.
(See 6 Troubleshooting)
4.4 Mains Protections
4.4.1 Inrush Current Limitation
Within 2 seconds of the VORTEX being switched on, the inrush current limiter
will increase mains current from nearly zero to nominal value. This value
de pends on program material, output level and speaker loads.
4.4.2 Mains Over Voltage Detection
Mains Over Voltage Detection is always operative. When the mains voltage
exceeds approx. 267 V (230 V operation), 134 V (120 V operation) or 117 V (100 V
operation), the amplifi er will switch off. When the mains voltage returns to nomi-
nal value, a soft start occurs.