External buzzer relay

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To get round the problem that the Simrad AI50 AIS alarm is not loud enough and that Simrad has been unwilling to assist in any way, just indicating that by opening the AI50 box i would void my warranty, I wired a noise activated relay, this is shown in the picture before it was enclosed in a waterproof box and the microphone (which is the green bit lying on the box) was attached to the AI50 box and enclosed so it was shielded from noises other than the AI50 alarm. When the AI50 alarm goes off, the noise triggers the relay which closes the circuit to a very loud buzzer bought from Maplin. This is a long way round the problem, but at least it works.

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