Camco D-Power 7 - Manual (Page 19)

D - P O W E R
S E R I E S
USER MANUAL
D-POWER 7
P.18
4.2.5 Mode Indicators
On the front panel there are two yellow LEDs to indicate the mode that is
set. In stereo mode (2-channel) none of them will be lit. In Parallel Mono
the (PM) LED will be lit and in Mono Bridge, the (MB) LED will be lit.
Amplifier in Parallel Mono mode
Amplifier in Mono Bridge mode
4.3 Power Amp Protection Systems
4.3.1 Clip Limiter
If the power amp is overdriven, the clip detection circuit triggers the micro-
processor. The processor reduces input signal level by controlling the
DCA. The strategy is implemented in software. For sinusoidal input signals
the microprocessor limits the input signal in such a way that non-linear
distortions of the signal never exceed 1 %.
The Clip Limiter can work on each channel independently (except in the
two mono operation modes). (To disable the Clip Limiter, see 4.1.4 Limiter
Switch.)
4.3.2 Under Impedance Limiter
As a result of incorrectly connected or defective loads, under impedance
or even short circuits may occur in one or both power amp channels.
The microprocessor constantly calculates the load impedance at the out-
put channels. If an impedance of less than 1,33 ohms/channel is detected,
the microprocessor limits the signal to the power amp until a subsequent
measure ment indicates that impedance has risen to a safe level. When-
ever the Under Impedance Limiter is active, the corresponding channel’s
On LED is turned off (See 5 Troubleshooting).
4.3.3 SOA Protection
To ensure that the power transistors are only used in the Safe Operation
Area (SOA), the SOA-protection in stereo mode switches back the rail volt-
ages of the respective power stage. In mono modes the rail voltages of
both channels are switched back.
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 immedi-
ately 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 OPERA
TION