Hello all!
I have an app on my phone (Interval exercise timer) which can be set to notify over a predetermined span of time with interval notifications. For instance, I can set it up to work for a whole hour with 10 min notifications.
My initial cheap solution was to use cheap target PC speakers ($11) to amplify the noise file that comes out of the line out from the phone. This works well, except that the volume is not there. The reason I need this much louder is that we are using it during a racquetball shuttle (grown men banging a small ball against a wall as hard as they can, generating tremendous amounts of noise to overcome).
I imagine an op amp driving a small relay that will close the circuit to a 110v capable siren (to be sure about the db level that I want to achieve).
Of course I want to insure that there is plenty of isolation between the phone and the 110v source.
Does anybody have some example circuits that I could use with as cheap as possible components?
If there is any further clarifying information that I can provide please let me know.
Thank you,
Tim
I have an app on my phone (Interval exercise timer) which can be set to notify over a predetermined span of time with interval notifications. For instance, I can set it up to work for a whole hour with 10 min notifications.
My initial cheap solution was to use cheap target PC speakers ($11) to amplify the noise file that comes out of the line out from the phone. This works well, except that the volume is not there. The reason I need this much louder is that we are using it during a racquetball shuttle (grown men banging a small ball against a wall as hard as they can, generating tremendous amounts of noise to overcome).
I imagine an op amp driving a small relay that will close the circuit to a 110v capable siren (to be sure about the db level that I want to achieve).
Of course I want to insure that there is plenty of isolation between the phone and the 110v source.
Does anybody have some example circuits that I could use with as cheap as possible components?
If there is any further clarifying information that I can provide please let me know.
Thank you,
Tim
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