AC mains voltage protection
If the AC mains voltage is outside the operational window (over or under
voltage), the power supply will automatically shut down. When the mains
voltage is above the minimum start voltage and below its maximum
operating voltage the amplifier will restart.
It takes a couple of seconds to self check (this is known as the "soft start"
or "slow start" sequence), the gain will gradually be increased back to the
previous set level and the fans will blow at high speed before going into
"idle". The two green "ON" LED's then indicate that the power supply and
output stage is operating correctly.
D.C. protection
There are two types of DC protection:
• Fuses on the supply branches of each channel.
• A DC crowbar protection circuit that shorts the output if more than 10 volts
is detected on the outputs. Both these circuits come into effect once a DC
level is detected.
9
DESIGN FEATURES
Cooling
MARTIN AUDIO MA Series amplifiers run very cool due to a patented heat
exchanger. The bi-polar output devices are mounted directly onto a copper
heat sink thereby avoiding thermal losses normally found when using mica
washers. The heat sink is mounted horizontally in front of a pressure
chamber and the air flow is constant along the whole heat sink. When cool
air hits the geometric fins of the heatsink, turbulence is produced thereby
enabling efficient cooling. (In a conventional tunnel design the end of the
heat sink away from the fan invariably gets hotter than that directly in front
of the fan).
Light weight
The MA 1.6 switch mode amplifier has a very good power to weight ratio,
making it one of the most powerful, lightweight 2u amplifiers available. This
is achieved not only by the design of the power supply and heatsink but
also by the use of an alloy chassis making rear rack supports unnecessary
in most applications.
Switch mode power supply (SMPS)
Switch mode power supplies are the modern solution to the problems of
size and weight. However, early examples of SMPS used in power
amplification were not ground breaking and literally adopted the type of
supply found in many computers today. The MARTIN AUDIO SMPS is
different in that it is regulated.
Martin Audio – MA1.6 Power Amplifier
E
NGLISH
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