Crown PIP-BP1X Technical Information download pdf (Page 21)

Page 21Reference Manual

Macro-Tech

24x6 & 36x12 Power Amplifiers

5 Technical Information

5.1 Overview

Your amplifier incorporates several new technological

advancements including low stress output stages, real-

time computer simulation of output transistor stress, an

advanced heat diffuser embodiment and a modular

system for signal input and processing. In addition,

Macro-Tech 36x12 models also have an articulated VZ

power supply in Channel 1.

Custom protection circuitry limits temperature and cur-

rent to safe levels while making the amplifier highly reli-

able and tolerant of faults. Unlike many lesser

amplifiers, it can operate at its voltage and current limits

without self-destructing.

Real-time computer simulation is used to create an ana-

logue of the junction temperature of the output transis-

tors (hereafter referred to as the “output devices”).

Current is limited only when the device temperature

becomes excessive—and just by the minimum amount

necessary. This patented approach is called ODEP or

Output Device Emulation Protection. It maximizes the

available output power and eliminates overheating, the

major cause of output device failure.

The amplifier is protected from all common hazards that

plague high-power amplifiers, including shorted, open

or mismatched loads; overloaded power supplies, ex-

cessive temperature, chain-destruction phenomena,

input

overload damage and high frequency blowups.

The unit protects loudspeakers from DC in the input sig-

nal, turn-on and turn-off transients, and it detects and

prevents unwanted DC in the output. The amplifier is

also protected from internal faults.

The patented four-quadrant topology used in the

grounded output stages is called the grounded bridge.

The grounded bridge topology takes full advantage of

the power supplies delivering peak-to-peak voltages to

the load that are twice the voltage seen by the output

devices and twice the voltage generated by the power

supplies.

The grounded bridge topology is ground-referenced.

Because the required current exceeds the limits of pres-

ently available components, composite output devices

are constructed to function as gigantic NPN and PNP

devices. Each output stage has two composite NPN

devices and two composite PNP devices.

The devices connected to the load are referred to as

“high-side NPN and PNP” and the devices connected

to ground are referred to as “low-side NPN and PNP.”

Positive current is delivered to the load by increasing

conductance simultaneously in the high-side NPN and

low-side PNP stage, while decreasing conductance of

the high-side PNP and low-side NPN in synchrony.

A wide bandwidth, multiloop design is used for state-

of-the-art compensation. This produces ideal behavior

and results in ultra-low distortion values.

Aluminum extrusions have been widely used for

heatsinks in power amplifiers due to their low cost and

reasonable performance. However, measured on a

watts per pound or watts per volume basis, the extru-

sion technology doesn’t perform nearly as well as the

thermal diffuser technology developed for

Macro-Tech

power amplifiers.

Our thermal diffusers are fabricated from custom con-

voluted fin stock that provides an extremely high ratio of

area to volume, or area to weight. All power devices are

mounted directly to massive heat spreaders that are

electrically alive. Electrifying the heat spreaders im-

proves thermal performance by eliminating the insulat-

ing interface underneath the power devices. The

chassis itself is used as part of the thermal circuit, and

this maximizes utilization of the available resources.

5.2 VZ Power (Macro-Tech 36x12 only)

VZ means Variable Impedance and is the name of

Crown’s patented articulated power supply technology.

This technology is what makes it possible to pack such

tremendous power into Crown’s

Macro-Tech 3600VZ

and

Macro-Tech 5002VZ

amplifiers. The high-power

channel of the Macro-Tech 36x12 uses this articulated

power supply technology.

5.2.1 Background

A power supply must be large enough to handle the

maximum voltage and current needed by the amplifier

to drive its maximum rated power into a specified load.

To fulfill this require-

ment, conventional

power supply de-

signs produce lots of

heat, are heavy, and

take up precious real

estate. And it’s no se-

cret that heat is one

of a power amplifiers

worst enemies. Con-

sider the circuit that

follows in Figure 5.1.

According to Ohm’s

Law, as your power

Fig. 5.1 A Typical

Power Supply

POWER

TRANSISTOR

POWER

TRANSISTOR

SPEAKER

LOAD

POWER

SUPPLY

–

1 2 ... 16 17 18 19 20 21 22 23 24 25 26 ... 33 34

Comments to this Manuals

No comments

Crown PIP-BP1X Technical Information Page 21

Comments to this Manuals

Related products and manuals for Processors Crown PIP-BP1X