Table of Contents
Advertisement
Unusual output conditions
The vast majority of amplifier faults show up as high
positive or negative DC output voltages. An
independent circuit in the Halcro amplifiers senses
any unreasonable DC output voltage and switches
the amplifier off if this occurs.
Likewise, if any excessive output current flows for an
extended length of time, this also implies a fault and
an independent circuit measures this and will shut
down the amplifier.
Power supply output current limiting
To further reduce the possibility of fault conditions
causing substantial damage, the power supply is
limited in its maximum available average output
current. Note that this level is higher than the
amplifier's normal current limiting conditions. The
power supply limit will only cut in under fault
conditions.
Internal power supply protection
There are numerous power supply protection
circuits, for example:
o Two independent over temperature cut outs
o Two independent master clock fault sensing
circuits
o All power supplies check for under/over-
voltage and over-current conditions, including
those for standby mode, active power factor
correction and switch mode power etc.
o The small signal power supplies have transient
diode over-voltage protection
Mains transient overload protection
The mains input is protected against all but the most
severe mains input transients. Three independent
circuits achieve this: two surge absorbers and high
energy inductive filtering.
Input overload protection
The inputs have over-voltage protection circuits,
which will handle most typical input overloads.
Amplifier inter-stage protection
Within the amplifier stages, there are more than a
dozen protection circuits.
22
Advertisement
Table of Contents
