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Com-Tech Power Amplifiers
Reference Manual
4.3 Protection Systems
Com-Tech amplifiers provide extensive protection and
diagnostic capabilities. Protection systems include
ODEP, “standby” and an AC circuit breaker. These fea-
tures provide protection under any conditions.
4.3.1 ODEP
Crown invented ODEP to solve two long-standing prob-
lems in amplifier design: to prevent amplifier shutdown
during demanding operation, and to increase the effi-
ciency of the output circuitry.
To do this, Crown established a rigorous program to
measure the
safe operating area (SOA) of each output
device before installing it in an amplifier. Next, Crown
designed intelligent circuitry to simulate the instanta-
neous operating conditions of the output devices. Its
name describes what it does: Output Device Emulation
Protection or ODEP. In addition to simulating the operat-
ing conditions of the output devices, it also compares
their operation to their known SOA. If ODEP sees that
more power is about to be asked of the output devices
than they are capable of delivering under the present
Fig. 4.2 ODEP, IOC and Signal Presence Indicator States
