This circuit that emits siren sound can be used in a fire alarm. We found it in an old American documentation. The signal must be applied to a good audio amplifier.
This circuit was found in a 90s American documentation from the 90s. The components are from that...
In the figure we have the circuit of a clamp-type microammeter described in the Radio Electronics...
The voltage-gain for this amplifier is 10. Other operational amplifiers can be use and the Power...