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11 advanced features – Crown Audio I-Tech 4x3500HD User Manual

Page 51

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I-Tech HD DriveCore Series Power Amplifiers

Operation Manual

page 51

11.1 Protection Systems
Your Crown amplifier provides extensive

pro tection and diagnostic capabilities, including

thermal level control, fault indicators, high-pass

filtering, DC protect, AC under/over volt age

protection, inrush limiting, and variable-speed

fans with tachometer feedback. Microprocessor

monitors fans, and signals an error via System

Architect if fans are not operating.

11.1.1 Thermal Level Control (TLC)
If the amplifier becomes too hot for safe

opera tion, the TLC will engage the input

compressor and the clip LED will illuminate. By

compress ing the input, the amplifier will not

generate as much heat and will have a chance to

cool down. The degree of compression is

proportional to the amount of overheating. This

feature allows the show to go on, rather than

having the amplifier shut down, and only occurs

in extreme situations.

11.1.2 Circuit Breaker
If the current draw of the amplifier exceeds safe

limits, this breaker automatically disconnects the

power supply from the AC mains.

11 Advanced Features

11.2 Global Switching Power

Sup ply with PFC
Thanks to its global power supply, the I-Tech

amplifier works anywhere in the world. There’s

no need to reset an AC mains voltage switch,

and no need to order a special model. The amp

will work and meet all specs on 100V - 240VAC,

50/60 Hz.
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 oper-

ate with a much smaller (and lighter)

trans former because they first convert the AC up

to a much higher frequency, thereby reducing

waste.
Power Factor Correction (PFC) controls how

your amplifier draws current from the AC mains.

Instead of drawing high-magnitude cur rent

spikes that reduce the capacity of your power

distro (and couple noise into other sys tem

components), PFC draws a smooth and quiet

current waveform that is in phase with the mains

voltage waveform. PFC allows you to reduce the

size and weight of your power distri bution and

improve the performance of your signal

processors.

11.3 6th Generation Class I

Cir cuitry
Class I (BCA, Balanced Current Amplifier)
Interleave technology allows high levels of
power output without all the associated heat
found in a conventional amplifier. This highly
efficient design also provides accurate,
uncol ored sound with very low distortion and a
high damping factor for tight, clean bass
response. And it can deliver more power to
reactive loads than conventional dissipative
designs (com fortably driving the latest high-
technology transducers). Class I also reduces
current draw of the AC mains, providing energy
conserva tion.

11.4 Color-Coded Rear Overlay
The labels on the rear panel are color coded to
group similar functions under common colors.