In the figure we have the trip circuit for a relay with audio signals. The circuit is from an 80's Radio Electronics. The relay is of the sensitive type of 12 V. For shooting with microphone use the following circuit.

In the figure we have the trip circuit for a relay with audio signals. The circuit is from an 80's Radio Electronics. The relay is of the sensitive type of 12 V. For shooting with microphone use the following circuit.