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4.5 PROTECTION CIRCUITS
The CMX25 is designed with a variety of protection circuits to provide safeguards for the
amplifier should any adverse electrical conditions occur or if the amplifier is accidentally
experiencing operator deviation of the design application. Listed below are the safeguards built
into the CMX25.
4.5.1 Over Heat Protection
The CMX25 critical components are mounted to heat sinks which are, in turn, air cooled by four
fans. Should a over heating condition occur, either through component failure or by a restricted
air flow, the CMX25 contains heat sensors that will shut down the system should an over heating
condition occur. As a result, the air inlet and outlet openings should be free of obstructions for
proper cooling of the amplifier. Operation is restored automatically when the amplifier cools to
normal temperature levels.
4.5.2 Input Protection
The CMX25 is designed to operate with less than a 0 dBm ( 1.0 mW ) input signal however, to
prevent over driving the amplifier, the Input Protection circuit will activate if the input signal
exceeds 3 dBm ( 2.0 mW ) and will automatically compensate for the increased input signal by
reducing the gain of the preamplifier. Even though the amplifier has an Input Protection Circuit,
overdriving the amplifier is not recommended, refer to paragraph 5.1.2 for more details.
4.5.3 Output Protection
The CMX25 incorporates a microprocessor controlled Output Protection Circuit which monitors
the Forward Power Meter indication and limits the out put power to 40 Watts. This feature
protects the amplifier from being over driven and causing damage to the power transistors.
