Crown CT 4150 Advanced Features, Accessories, CT Power Amplifiers, page, Operation Manual, Fault

CT Power Amplifiers

13 Advanced Features

13.1 Protection Systems

Your Crown amplifier provides extensive protection and diagnostic capabilities, including thermal level control, fault indicators, high-pass filtering, DC protect, AC under/over voltage protection, inrush limiting, and a convection-cooled chassis.

13.1.1 Thermal Indicator

If the amplifier becomes too hot for safe operation, the channel that is generating too much heat will be shut down until the temperature is reduced.

13.1.2 Fault

The amplifier will enter a Fault state if the amplifier senses an unsafe condition. This protection is for both internal and external faults. It is critical to check all wiring to and from the amplifier to ensure the fault is not caused by external conditions. Once wiring has been verified to be correct, and the fault condition persists, see Section 17 Service for Servicing information.

13.1.3 High-Pass Filters

HPF’s are traditionally used in Hi-Z applications. The Com-Tech DriveCore is a low Z amplifier but can be used in conjunction with the XFMR 4/8 transformer box for Hi-Z applications. If the amplifier is to be used in a Hi-Z application, then it is very important to use the HPF to prevent transformer saturation.

13.1.4AC Under/Over Voltage Protection

If the AC line voltage drops below 25% or rises above 15% of the nominal operating voltage of the amplifier, the amplifier’s power supply turns off and the blue Power LED flashes. The amplifier­ will turn back on when the AC line voltage returns to safe operating levels (within ±10%).

13.1.5 Circuit Breaker

A circuit breaker located near the IEC power inlet protects the amplifier from excessive AC current draw.

13.1.6 Convection-cooled Chassis

The DriveCore amplifiers require no fans for cooling, providing quiet operation and optimum efficiency.

13.1.7 Auto-Standby

If amplifier does not see input signals for a period of 30 minutes, the amplifier will go into standby mode. The amplifier will come out of standby mode once an input signal is present. This feature is activated via DIP switch #2 on the back of the amplifier. The amplifier will be configured with Auto-Standby turn-on from the factory. When the amplifier is in Standby, the Ready Indicator on the front panel Display will flash.

13.2 Features

13.2.1 Switching Power Supply

Crown’s Switching Power Supply minimizes the amplifier’s weight. Typical non-switching power supplies require large, heavy transformers in order to produce the required power at the output stage. These transformers must be large to operate at 50 to 60 Hz (standard AC supplied by the power company).

By contrast, switching power supplies can operate with a much smaller (and lighter) transformer because they first convert the AC up to a much higher frequency, thereby reducing waste. The power supply is voltage-specific, allowing use in regions using 100V or 240V.

13.2.2 Power Mode

Deep sleep and green mode allow the amplifier to operate at all times with the lowest possible power level.

13.2.3 Adaptive Rail Technology (ART)

Crown has developed a voltage rail technology that delivers power on demand. ART is at the center of CT DriveCore’s Green mode that provides up to an additional 10% of efficiency. Through ART, the CT DriveCore is always operating at maximum efficiency.

13.2.4 DriveCore Power Stage

Crown has worked with Texas Instruments to develop an audio amplifier on a micro-chip. The result is DriveCore chipset that introduces audiophile quality for an installation amp:

-Greater than 90% Efficiency -118dB Signal to Noise

-THD less than .05% in midband frequencies

14 Accessories

14.1 XFMR 4/8

The ComTech DriveCore amplifier is only capable of low Z applications. It is necessary to use an outboard transformer for Hi-Z applications. Crown highly recommends the use of the XFMR 4/8 transformer box. This transformer box is designed to mate with the top of the ComTech DriveCore Amplifiers. See XFMR data sheet for wiring diagram.

14.2 Rack Support Ears

The ComTech DriveCore amplifier requires front and back rack support for proper mounting. These have been provided with the amplifier.

page 14 Operation Manual