Protection Circuitry - Cambridge Audio EDGE W User Manual

User manual

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Protection circuitry

Last updated: August 9, 2022 05:05. Revision #5723

The EDGE W includes Ampliﬁer Protection Circuitry to detect faults with Over Temperature, DC and Over Current. If any of these faults are detected the

LED standby button will turn red.

Over Temperature

Over temperature is caused by a combination of high listening levels and low impedance speakers. The Edge W includes temperature detection which

constantly monitors the heat generated by the output transistors.

If the monitored temperature reaches a high level (suitably within the limits of the output devices) the ampliﬁer will automatically switch into a fault

mode To protect itself from damage.

If the loudspeaker impedance is low the temperature of the ampliﬁer may rise faster as the ampliﬁer is working harder. If the ampliﬁer is mounted in a

cabinet or the ventilation slots are obstructed the over temperature detection may activate/reactivate after a short listening time.

Remedy - Leave the unit for 15 minutes to cool down before pressing the Standby button to resume normal operation. If the unit has not fully cooled

down then the temperature may reach the limit soon after the ampliﬁer is powered up.

EDGE W oﬀers loudspeaker protection if the output of the ampliﬁer goes to a high constant voltage (DC) because of some internal fault. This is a rare

fault, although detecting it will protect your loudspeakers from damage.

Remedy - Due to the necessary sensitivity of the DC protection circuit, extremely hard clipping of the ampliﬁer may cause DC protection to be

triggered. If this fault occurs, please contact your dealer for service or our support team https://www.cambridgeaudio.com/support-query.

Over Current

EDGE W oﬀers V/I (voltage/current) protection by constantly monitoring the output transistors to keep them working inside their Safe Operating Area

(SOA). The SOA is a set of limits given by the output transistor manufacturer to ensure reliability. The V/I protection has been incorporated within the

ampliﬁer circuitry to provide a fast response to temporary overload conditions. When the V/I protection is triggered the unit will continue to operate but

distortion may be heard as the unit protects the output transistors.

Remedy - Reduce the volume. If distortion is still present, check the speaker connections and impedance ratings.

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